ARRT-T practice questions
ARRT · ARRT-T · 300 questions
Original practice questions for the ARRT Radiation Therapy (T) Certification Examination exam, covering every domain of the official exam outline.
This course contains the use of artificial intelligence.
About the ARRT-T exam
- Questions
- 200 scored questions plus 30 unscored (pilot) questions
- Passing score
- Not published in the content specifications
- Format
- Computer-based, administered at a standardized testing center
Schedule this exam The certification this earns
Exam details published by the vendor, checked 3 November 2026. Vendors change fees and formats without notice — confirm on the vendor's own page before you book.
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Patient Care: Patient Interactions and Management (14%) · 42 questions
- A patient with widely metastatic cancer stops all disease-directed treatment after a goals-of-care discussion, wants to remain at home, and has pain and breathing comfort needs that could worsen at any hour. The family asks the therapist which service will send a coordinated team to the house for end-of-life comfort care. Which support professional should the therapist name to this family?
- A patient's daughter asks the team for his diagnosis and schedule; he is alert and waiting for today's fraction, yet no authorization form on file names her. Which privacy action should the therapist take first before speaking with her?
- A patient with widely metastatic disease is nearing the end of life and wants to remain at home. The family needs access to symptom control around the clock, help with personal care, regular nursing visits, and counseling that continues after the death. Which support resource best matches every one of those needs?
- During a simulation visit, an adult daughter says her father has authorized her to speak for him and asks for his dose and side-effect details. The chart shows no documented representative, and a colleague is ready to walk her through the plan while the patient rests. Which disclosure decision best follows HIPAA and the Patient Care Partnership before anything is shared?
- A patient with advanced pancreatic cancer has left curative treatment and entered hospice care at home. The family tells the visiting nurse that they want someone to help them pray, reconcile with their faith, and find meaning in what is happening. Which hospice team member should visit to address this spiritual need?
- A patient scheduled for her fourth treatment tells you the daily trips are no longer worth the discomfort, and her daughter, who drives her, asks you to persuade her to finish the course. The patient is alert and answers for herself. Which response best applies the patient's goals of care?
- A patient breathing 2 liters per minute of oxygen through a nasal cannula from a cylinder on a wheeled stand must move from the transport chair to the treatment table. She is unsteady, her oxygen must keep running, and you are the only staff member available. What is the safest action before the transfer?
- A patient on 3 liters of nasal cannula oxygen and a pole-mounted infusion pump stands for the first time after a fall and becomes lightheaded. The patient can bear weight with one helper, and the infusion must continue without interruption. What should the helper do first to support the patient while keeping the infusion running?
- Before today's fraction, the console record shows the field label and fraction size from an earlier plan, while the current signed prescription lists a different treatment site and dose. The patient is on the table and ready. Which identity, site and prescription verification must happen before beam-on?
- Before an afternoon fraction you notice the record shows a plan for the left chest while the skin marks and the immobilization tray match the right chest. Which verification step must happen before the beam is delivered?
- A new course of external beam treatment is ready to start, but the signed prescription lists only the total dose and fractionation schedule, and the record-and-verify entry shows a generic anatomic region instead of a specific site. Before the first fraction, which verification step confirms the treatment site?
- A patient who needs help standing is being moved from a wheelchair to the treatment couch while wearing a nasal cannula and connected to an infusion pump, and both the pump and the oxygen unit sit on separate rolling poles. The patient can push up with both arms, and a second staff member is available. Which transfer technique keeps the patient and both lines safe during the move to the couch?
- During morning setup, a patient who had a near-fall in the waiting area reports lightheadedness every time they stand, and the chart shows a 3 kg weight gain since the last visit. The therapist is about to help the patient onto the treatment couch. What should the therapist do before positioning the patient?
- Mid-fraction, the therapists stop the beam when a patient with dementia becomes agitated and starts thrashing their arms. One therapist holds the patient's arms at their sides until a second staff member arrives, and the thermoplastic mask stays secured as always. Which statement correctly distinguishes restraint from immobilization in this setup?
- A patient receiving radiation for lung cancer with known bone metastases starts to rise from a waiting-room chair and says the room feels unsteady. The slot is running late, and the patient walks with a cane. What should the therapist do before the patient walks to the couch?
- A patient with dementia becomes agitated during setup, tries to sit up, and grabs at the couch rails. To keep her still for the beam, a therapist buckles a soft belt across her chest and thighs and the fraction is finished. The department later reviews the event under its patient safety policy. Which classification applies to what the therapist placed on this patient?
- A patient who has completed several weeks of daily treatments sits up from the couch and reports the room spinning. The therapist notes pale skin, a pulse of 104 taken while the patient stands, and that the patient drank very little fluid overnight, while last week's readings were unremarkable. Which measurement sequence should the therapist obtain to assess for an orthostatic blood pressure change?
- On the treatment table, a confused patient with brain metastases repeatedly pushes at the headrest and tries to sit up. The physician has ordered padded wrist restraints for the treatment sessions, and the thermoplastic mask is already in place for positioning. Which statement correctly distinguishes the restraint from the immobilization device?
- During a CT simulation with iodinated contrast, a patient on the table develops widespread hives, hoarse speech, and audible wheeze within minutes. The treatment team is present and the physician is down the hall. Which action takes priority in managing this allergic reaction?
- While covering another treatment room, you notice a coworker open the chart of a patient outside her assignment, saying she recognized the vehicle parked out front and wanted to know the diagnosis. She closes the record and laughs it off, and nothing leaves the department. Which response best applies the ARRT Standards of Ethics to this chart access?
- On your lunch break in the department's shared cafeteria, you hear a therapist describe a patient's diagnosis, treatment site, and unusual daily setup to two coworkers from another unit. The therapist mentions no patient name and says that keeps the discussion private. Which response best applies the ARRT Standards of Ethics to this conversation?
- While a planning CT is running with IV contrast, a patient develops widespread hives, a hoarse voice, and an oxygen saturation of 89% two minutes after the injection starts; the line is still infusing, the emergency cart is in the room, and the physician is down the hall. Which response best manages the reaction and communicates the critical findings?
- A patient's sibling waits at the counter and asks how the daily treatments and the skin reaction are going, saying the patient has already told them everything. You must reply in a way that follows the ARRT Standards of Ethics and protects the patient's privacy. Which response best applies the confidentiality principle of the ARRT Standards of Ethics?
- During a head and neck setup, a patient suddenly reports an itchy throat and chest tightness, and the therapist hears stridor with each breath. The therapist has stopped the beam and entered the vault alone. Which response best manages this suspected anaphylactic reaction?
- During a teaching visit, a patient with limited English proficiency must learn positioning, skin care, and what erythema means before starting daily treatments. The patient's teenage child offers to translate. The therapist wants a reliable check that the instructions landed. Which communication approach best confirms the patient understands the medical terms and instructions?
- A patient with a documented MRSA lesion on the forearm finishes a fraction in a shared treatment room. In ten minutes that same couch, arm board and accessories will hold the next patient, who will be positioned by hand. Which infection control step breaks the chain of transmission before that setup?
- A patient with limited health literacy is starting a course of breast radiotherapy and nods politely whenever staff walk through the daily routine. Before the first fraction, the therapist needs solid evidence that the patient has actually processed the routine rather than just agreeing to it. Which communication method best verifies the patient's understanding?
- A patient whose first language differs from the one used by every staff member is about to begin a planning session while a teenage relative translates your explanation of the word 'isocenter.' You need certainty that the patient understands the term before the session starts. Which method best confirms the patient's own understanding of the explanation?
- A patient on contact precautions for a resistant skin organism finishes treatment and leaves drainage on the couch pad, mask, and headrest. The same accessories are needed for the next patient in fifteen minutes. Which infection-control steps should the therapist take to break the chain of infection at the treatment unit?
- A patient with confirmed Clostridioides difficile infection has an episode of watery diarrhea that soils the treatment couch and floor partway through a fraction, and another patient is due in that same room shortly. Which pair of actions breaks the chain of C. difficile transmission before that next setup?
- A bottle of a chemical used in your department breaks open on the floor, and the label is soaked and unreadable. Two therapists are about to start cleaning it up with absorbent pads. Which source of hazard information should guide their actions before cleanup begins?
- During a CT simulation education visit, a patient asks whether the scan itself is the treatment, why the same position and immobilization must be repeated later, and whether the metal implant in the hip must be removed. Which explanation addresses the scan purpose, the daily setup, and the hip implant together?
- A patient with a dental implant and a fear of tight spaces arrives for a head-and-neck CT simulation with a thermoplastic mask. The patient asks whether the scanner's magnet could disturb the implant and whether the scan itself is the day treatment begins. Which explanation best prepares this patient for the simulation?
- While casting a block, a small splash of molten Cerrobend hardens on the workbench; nobody is burned, but the pot's label is scorched and unreadable. Which document should guide the cleanup and the protective clothing used before the residue is removed?
- A patient with stainless steel surgical plates in his shoulder grows anxious during the planning visit. He asks why the CT simulation lasts longer than a routine scan, why small marks were drawn on his skin, and why he must lie in exactly the same position each day. Which explanation correctly addresses the implant, skin marks, and positioning concerns during the CT simulation?
- A student in the mold room is told to help skim dross from the pot while Cerrobend is molten. The alloy contains lead and cadmium, the splash hazard reaches the eyes and forearms, and printed safety data sheets are kept at the workbench. Which SDS section should the student use to select the eye and skin protection for this task?
- A patient with a documented prior iodinated contrast reaction of hives, facial swelling, and wheeze needs a contrast-enhanced CT of the chest, and kidney function is normal. Which contrast administration plan addresses both the prior reaction and the imaging requirement?
- A patient arrives for a contrast-enhanced CT of the chest. The intake form records moderate hives and wheezing after iodinated contrast two years ago, normal kidney function today, and clear breathing between events. Emergency drugs and airway equipment are in the room, but the schedule is tight. Which contrast management approach best fits this patient's risk profile?
- A patient in week 2 of a three-week palliative course says the knee cushion and arm cradle used at simulation are uncomfortable, so they have been lying without them. They insist the skin marks still line up, so the setup is fine. Which counseling point best reinforces daily setup reproducibility?
- During a contrast-enhanced CT simulation, a patient with an IV in the hand reports sudden burning at the wrist, and the power injector stops as a firm swelling rises along the forearm. The scan can be repeated later. Which immediate response to contrast extravasation should the therapist carry out at the bedside?
- A head-and-neck patient at fraction 15 says the thermoplastic mask feels tighter than it did at simulation, has been scrubbing the drawn skin marks in the shower, and applies moisturizer over them each evening. Which guidance should you reinforce before today's set-up?
- A patient midway through a chest treatment course tells you one of the alignment marks has faded and that she has been adding her own dot at home so she can line up more easily. She asks whether that helps the team. Which instruction about the faded mark and her own dot keeps her daily setup consistent?
Patient Care: Patient and Medical Record Management (9.5%) · 29 questions
- A patient midway through a pelvic course reports looser stools and cramping at every visit and has been drinking less water because of the urgency. The symptoms have intensified over the past few days, and the radiation oncologist reviews the chart after the day's treatments are finished. How should this worsening bowel side effect be managed and recorded?
- The record-and-verify printout for a 30-fraction course already documents the prescribed dose, the daily fraction, the beam energy and the treated field arrangement for every session. During a documentation audit, the supervisor notes that how the patient was placed still has no per-fraction entry. Which treatment-record element should be added to each session's documentation?
- Before a patient's first fraction, the therapist reviews a lung cancer chart containing a chest CT describing a peripheral nodule, a bronchoscopic biopsy identifying adenocarcinoma, a PET report showing no uptake outside the chest, and surgical pathology reporting negative margins with every sampled lymph node negative. Which statement correctly attributes each finding to the report that establishes it?
- A patient in week three of pelvic radiation reports loose, crampy stools after meals and looser clothing at the weekly check-in. The nurse asks you to reinforce nutrition advice while the assessment note is open. Which dietary counseling point best controls the symptom pattern and protects the patient's weight?
- During simulation a patient mentions an aunt who had cancer, notes that she herself has never had a screening test, then asks what her family history means for her own risk. Which explanation of cancer risk factors and screening should the therapist give at this point?
- At the end of an evening shift, the therapist realizes one patient's treatment was delivered but was missing from the day's charge log, so the billing count is short by one session. Under the routine charge-capture process, which documentation step should happen first to capture that charge for the date?
- Before treatment planning, a therapist reviews the operative and pathology reports for a patient with colon cancer. The report describes a 5 cm adenocarcinoma invading through the muscularis propria into pericolonic fat, lymphovascular invasion present, all surgical margins clear, and 3 of 16 lymph nodes positive for metastasis. Which finding in the pathology report documents regional nodal involvement for this plan?
- During a weekly chart check, the record already documents the patient identifier, date, machine, energy, and the treated field. The therapist must confirm that the number of treatments delivered matches the physician's order before the next session. Which pair of record entries should be checked to verify that?
- During a consultation, a patient whose mother and sister both had breast cancer asks why she was told to begin screening earlier than friends of the same age. You want to document the discussion accurately for the record. Which explanation of cancer risk factors fits her situation?
- Yesterday a linac fault stopped treatment partway through the fraction; the beam was restored under departmental policy and the remaining monitor units were delivered, but the treatment note says only that the fraction was completed. Which entry best documents this interrupted fraction?
- At the weekly review for a prostate cancer patient, the record shows a hemoglobin that has drifted down to 11.2 g/dL, normal white cell and platelet counts, normal kidney studies, and a PSA that has fallen from 14 to 5 ng/mL across the treatment course. The patient reports mild tiredness but is eating and drinking well. Which laboratory finding is most directly related to the prostate cancer burden?
- A patient in the fourth week of treatment to the chest has weeping, tender skin in the fold beneath the breast where two skin surfaces rub together. The course must continue daily, and the team also needs to know when this finding should reach the nurse. Which care plan best manages this treatment side effect?
- Under department policy, a treatment variance must be documented during the same shift with the event timing, dose delivered, and everyone notified. After a pelvis fraction, verification imaging shows the patient was misaligned during part of the beam-on time, and the physician and physicist are both reachable right now. Which entry satisfies the policy?
- A patient in week three of treatment to a regional site reports pink, dry, itchy skin limited to the marked treatment area, with no blisters or open areas. The therapist documents the skin assessment before today's fraction, and the physician has directed that treatment continue. Which assessment finding and management note should be recorded?
- Before a first fraction, a therapist reviews a new chart holding a history and physical describing a right breast mass with a suspicious axillary node, a mammography report noting a 2.8 cm spiculated mass, a bone scan showing one sclerotic rib lesion, and a core biopsy pathology report reading invasive ductal carcinoma. Which document should confirm the histology listed on the treatment record?
- During the monthly billing reconciliation at a busy radiation oncology clinic, a therapist notices that the charge-capture system posted a cone-beam CT charge for every fraction of the past week. Cone-beam CT was used only on the first and last fractions, while planar portal images were taken on the other days, as confirmed by the daily imaging notes. Which correction to the posted charges should be made before the batch is released?
- A patient on pelvic radiation reports more gas and cramping since the last visit. You review their food diary together, suggest smaller meals and fewer gas-forming foods, and answer questions about eating around treatment times. The note must show both what you assessed and what you taught for the next therapist. Which entry best documents this dietary counseling?
- A patient receiving pelvic radiation reports new bruising and nosebleeds that started this week. Today's CBC shows white cells 5.8, hemoglobin 11.2, and platelets 64. Which laboratory finding should drive the therapist's action before today's fraction is delivered?
- During a new-patient evaluation, a person who has smoked for decades but feels completely well asks what a screening test is for, and mentions a parent who had a different cancer. The clinic tailors prevention advice to each person's history. Which explanation of cancer risk factors and screening is accurate?
- Before today's fraction, a patient on concurrent chemotherapy and pelvic radiation has labs showing white cells down from last week, platelets unchanged, hemoglobin steady at the patient's usual baseline, and a normal BUN. The patient now reports a sore throat and chills. Which result should be escalated to the oncology team right away?
- At the end of an evening shift, a therapist checks the treatment area's charge report before the midnight billing cut-off. Three fractions were delivered and documented, but the report shows one fraction posted twice and one fraction missing. Which reconciliation step best resolves these charge-capture errors?
- A patient being treated for a head and neck tumour reports painful mouth sores at today's review, is drinking less than usual, and has lost weight since the last visit. Which action completes the on-treatment assessment before today's fraction?
- During a quarterly chart audit, a lead therapist finds several fractions that record only the date, treatment machine, dose delivered, and fraction number, while the signed prescription and plan sheet are filed separately. Which additional treatment details best complete the documentation for each fraction?
- During week three of pelvic treatment, a patient reports four loose stools a day, cramping, little appetite for solid food, and a dry mouth by late afternoon. The therapist is documenting the daily side effect assessment and wants guidance that fits this bowel reaction. Which dietary advice should be recorded and given to the patient?
- A patient on thoracic radiation reports painful swallowing and has begun skipping meals, so the therapist counsels briefly before the fraction. Guidance must maintain calories and fluids, avoid foods that irritate the raw throat, keep food temperature mild, and be recorded with any change reported to the nurse. Which dietary counseling plan meets all four requirements?
- While reconciling charts at the end of shift, you find a record showing a completed fraction, but you remember the beam stopped partway through and was re-delivered after an unplanned restart. Your department’s written policy requires documenting treatment variances in the record and filing a variance report before shift end. Which entry and reporting action follows that policy?
- In week four of pelvic chemoradiation, a patient reports dizziness when standing and new bruising on both arms. The blood work shows hemoglobin 9.0 g/dL, a white cell count of 3,100 per microliter, and platelets of 95,000 per microliter, with the BUN inside the lab's reference range. Which interpretation best accounts for both symptoms using these results?
- A patient returns for simulation after breast-conserving surgery. The operative note records titanium clips around the cavity, pathology reports a 2.6 cm tumor with clear margins, and the preoperative film lists a 12 o'clock lesion. Which record element should guide identification of the boost target volume on the planning CT?
- During a new-patient evaluation, a woman tells you that her mother and maternal aunt were both diagnosed with breast cancer in their forties, and she asks what that means for her. She reports feeling well today. Which statement about her family history and screening plan belongs in the evaluation record?
Safety: Radiation Physics and Radiobiology (11.5%) · 35 questions
- A treatment plan for a 62-year-old with lung cancer delivers 60 Gy in 30 fractions to a mediastinal target. The plan's dose-volume summary reports a mean dose of 24 Gy to the combined lung volumes and 40 Gy to the heart, while the department's planning-screening table lists TD5/5 values of 20 Gy for lung and 45 Gy for heart. According to this table, which comparison should trigger a plan review?
- During a routine plan review the physicist notes that the spinal cord maximum sits just below the quoted TD 5/5 value for a short cord segment, and the physician asks how that tolerance number should be read. Which interpretation of the TD 5/5 tolerance level applies to this cord dose?
- During monthly machine checks, an ionization chamber reports exposure, a phantom measurement gives the absorbed dose at depth, a worker's dosimetry record gives effective dose, and the physicist records air kerma at the panel. Which statement correctly matches each quantity to its SI unit?
- A clinic is replacing a Cobalt-60 teletherapy unit with a linear accelerator, and the physics team notes that one machine's output drifts down over time while the other holds steady unless the energy setting changes. Which explanation of how these two radiation sources produce and control their beams is correct?
- During morning output checks, a Cobalt-60 unit reads lower than it did last month, while the linac reads the same as yesterday. The physics group asks the therapists to explain the pattern. Which statement correctly compares how the two beams are produced and how their output changes over time?
- In a department safety huddle, a trainee reviews the day's records: patient skin absorbed dose of 2 Gy, an eye-lens dose-equivalent reading of 0.3 mSv, a survey reading of 0.5 µC/kg, and tube output air kerma of 12 µGy per exposure. Which recorded value already includes a weighting for radiation type?
- A patient who completed a full course of pelvic irradiation years ago now needs a second postoperative course that partly overlaps the old high-dose region. The new plan uses a similar dose per fraction and treats a similar tissue volume. Which factor most threatens normal tissue tolerance in the overlapping area?
- During a physics in-service, a resident compares two beams delivering the same absorbed dose to a tumor and asks why the neutron beam kills more cells than the megavoltage photon beam. Which beam property accounts for the greater biological effect at equal dose?
- A student is puzzled that raising the source-to-surface distance from 100 cm to 150 cm for a lung field lowers the dose rate even though field size and beam energy are unchanged. The physicist asks the student to name the governing principle. Which physics principle explains the reduced intensity at the greater distance?
- During a routine output check, a therapist measures an ion chamber in air at 100 cm from the source, then moves the same chamber to 150 cm with the beam and every machine setting unchanged. The physicist asks the therapist to predict the new reading before it is recorded. Which reading should the therapist expect from the inverse square relationship at 150 cm?
- During a physics review, a photon beam and a neutron beam are compared: the neutron beam kills the same cells at a lower physical dose and shows a smaller increase in cell kill when oxygen is added. Which radiobiologic principle explains the neutron beam's higher effectiveness?
- A thoracic plan places a large volume of lung in the high-dose region, and the patient's smoking-related lung function leaves little room for serious late injury. With the total tumor dose held constant, which fractionation strategy best protects the late-responding lung tissue?
- A pelvic patient is receiving a weekly radiosensitizing chemotherapy drug during external beam treatment, has daily CBCT image guidance, and a brachytherapy boost is planned once the beam course ends. Before that boost is scheduled, which dose contribution should you flag for the physicist so tissue tolerance for bowel and skin is assessed correctly?
- Before a second course is approved over a previously treated region, the team weighs the earlier external beam courses, concurrent chemotherapy, and routine image guidance. Which statement best describes how these contributions should be considered when judging normal tissue tolerance?
- A patient undergoing pelvic radiation therapy asks the therapist to explain the skin redness that appeared steadily as the dose accumulated, and also whether treatment could raise her chance of leukemia later in life. Which classification correctly pairs these two outcomes with their radiation effect types?
- During a physics in-service, a resident reviews how a 6 MV photon beam loses intensity as it passes through soft tissue. Which statement about the dominant photon interaction and attenuation is correct?
- During a planning huddle for a chest wall boost, the team compares a 6 MV photon field with a 9 MeV electron field on the same patient. The photon curve falls off gradually with depth while the electron curve drops steeply after a shallow buildup and then reaches near zero. Which interaction explanation accounts for that difference in tissue?
- During a break in a pelvic fraction, a patient of childbearing age who received scatter dose to the ovaries asks whether any injury could be passed on to children she has later. Which category of radiation effect does this question describe?
- During a power outage, a therapist notices the survey meter in the sealed-source storage area still reads above background, while the accelerator vault reads normal with no power running. Which comparison between radioactive-source and machine-produced radiation explains this difference?
- A resident reviewing a linac commissioning report finds a target absorbed dose, a whole-body effective dose from scatter, an exposure reading from a survey meter, and an in-air kerma measurement. The physicist wants each quantity classified before the report is signed. Which statement correctly gives the unit used to report each quantity?
- During a chart check you see a tolerance column listing TD 5/5 values for the spinal cord, lungs and kidneys beside the prescribed dose. The team is confirming that each critical structure stays within tolerance. Which statement correctly interprets a TD 5/5 tolerance value?
- During weekly linac checks, a trainee notes three readings: the plan's prescribed target dose, a reading taken outside the vault with an ionization survey meter that reports exposure, and the monthly badge result from the dosimetry service. The physicist also asks for a reminder about air kerma. Which statement correctly matches each reading to its quantity and unit?
- A clinic stores a sealed radionuclide unit beside a linac for cross-checking calibration. The radionuclide keeps emitting during a power outage, while the linac makes no beam; both are checked against the same absorbed-dose standard. Which statement best distinguishes radionuclide emission from machine-produced radiation?
- A plan delivers the prescription dose to the target while a large volume of late-responding soft tissue sits inside the high-dose region. The oncologist wants to lower the risk of a late normal-tissue reaction, but the target dose and the dose per fraction must both stay the same. Which change to the plan would most reduce that late-reaction risk?
- A hemithorax field for a large patient is too wide for the department's standard 100 cm SSD, so the physicist plans treatment at 120 cm SSD and recalculates before the first fraction. Compared with the 100 cm setup, how do beam output and percentage depth dose change at 120 cm SSD?
- During chart rounds, a thoracic plan shows the spinal cord dose held just below the department's cited TD5/5 limit for a short cord segment, and the team is comparing several serial organs before approval. A student asks how to read the TD5/5 tolerance value. Which statement correctly interprets that number?
- A pelvic tumour is treated with conventional fractionation, and follow-up imaging shows the central part regrowing while the outer part shrinks. The physicist explains the oxygen effect to the team. Which principle best accounts for the greater survival of the poorly oxygenated cells at the same dose?
- In a laboratory comparison, hypoxic and well-oxygenated cell cultures receive the same absorbed dose from a 6 MV beam and from an experimental beam. The experimental beam kills hypoxic cells nearly as well as oxygenated ones, and splitting its dose into two parts with a gap changes the kill very little. Which radiobiologic feature of the experimental beam explains both observations?
- For a palliative treatment, the team moves the source-to-surface distance from 100 cm to 140 cm so the patient's arm can rest comfortably at the side, and they keep the skin field size identical in both setups. Setting aside any monitor unit recalculation, how does the dose at a fixed depth change when the source-to-surface distance is increased?
- A patient with pelvic disease is receiving concurrent radiosensitizing chemotherapy, has image-guidance scans before every fraction, had a planning CT at simulation, and completed a brachytherapy boost earlier in the course. The skin reaction in the treatment area is stronger than expected. Which factors should you review when judging the response?
- A physics resident is auditing the department's beam data and notes two setups: a 6 MV photon beam treating a target 10 cm deep in soft tissue, and a 9 MeV electron beam treating a chest wall where the range spans only a few centimeters. Which statement correctly identifies the dominant interaction for each beam?
- A patient finishing treatment asks whether the radiation could cause a second cancer years later, whether it could affect a future pregnancy or her future children, and why her skin reacted only during the weeks of treatment. Which explanation best distinguishes these radiation effects?
- A patient with locally advanced disease is three weeks into a large-field course with concurrent radiosensitizing chemotherapy when mucosal and skin reactions develop faster than expected. The physician asks whether the daily fraction size should be raised to finish sooner. Considering fractionation, treated volume, and the sensitizing drug together, what should guide the dose-per-fraction decision?
- A patient at eleven weeks of pregnancy is referred for palliative radiation to a single bone metastasis. She asks what the exposure could mean for the baby now and whether effects could surface years later. The team has reviewed fetal dose limits and gestational timing. Which statement best describes the stage-specific fetal risk at this point?
- A plan review compares a shallow chest wall scar treated with a 6 MeV electron cone against the mediastinum treated with 6 MV photons in the same patient. Which depth-dose behavior explains the electron choice for the scar?
Safety: Radiation Protection, Equipment Operation, and Quality Assurance (14%) · 42 questions
- During a source inventory with the storage safe door open, a calibrated meter 30 cm from the exposed source reads 12 mrem per hour, and staff must enter the room to complete the check. Wipe tests show no removable contamination, and the department wants an audible warning if levels rise. Which posting and monitoring arrangement applies to this area?
- A chest wall target sits over the lung, the open 6 MV field extends 2 cm past the target on every side, and the plan shows slight dose build-up near the skin. Which beam change best limits dose to uninvolved tissue while keeping the target dose unchanged?
- A medical physicist is documenting monthly output constancy for a 6 MV beam by measuring dose at reference depth in water against the machine's saved baseline. The result must be accurate to about one percent and available immediately so any drift can be corrected before the next treatment day. Which detector is the best choice for this output measurement?
- During weekly output QA on a linac, a reading comes back outside the department's tolerance limit, and physics has placed the unit on hold for review. The therapist must finish the log entry before the shift ends, and the department requires the reading, the limit it missed, and the response in the record. What should the QA entry for this out-of-tolerance result contain?
- In a photon treatment head, a stream of electrons leaves the accelerator and must be converted into a usable x-ray beam before the collimating devices shape it. Which linear accelerator component performs this electron to photon conversion?
- The radiation safety officer reviews dose records for individuals who hold no occupational assignment. One person waits in the uncontrolled public lobby on a regular schedule, carries no occupational dosimetry badge, and has no declared pregnancy. Which annual effective dose limit applies to this person's recorded exposure?
- A shielding review of a new X-ray room maps three surfaces: the wall behind the patient sits in the direct beam, the corridor wall only receives scatter from the patient, and the floor is struck when the tube points downward. Which statement correctly classifies these barriers?
- During a treatment plan review, the pelvic field is being treated with jaws open well beyond the target plus setup margin, so a band of bowel sits inside the open beam. The oncologist wants normal tissue dose reduced while target coverage stays the same. Which beam delivery change best limits unnecessary patient dose?
- The daily treatment-linac routine covers safety-device tests, geometric checks, dosimetric measurements, and mechanical checks, and each part is logged separately. The physicist asks which item is a safety-device test. Which check belongs in that part of the daily routine?
- During an annual radiation protection survey of a linac running above 10 MV, you must record neutron dose equivalent at several gantry angles and in the treatment room maze, with a live reading at each point. Which detector should be used to perform this neutron survey?
- During commissioning of a linear accelerator vault, a calibrated survey at an accessible position 30 cm from the maze entrance measures a dose equivalent rate of 40 mrem per hour while the beam is on, and the outer corridor beyond the maze stays below 0.05 mrem per hour. Staff can reach that entrance mid-treatment if the door interlock is bypassed. Under the federal radiation-area criterion, what classification and posting apply, and what controls should this site use at the entrance?
- A therapist's annual dosimeter report shows a deep dose equivalent well below the regulatory occupational limit, yet the value has climbed steadily over the past three quarters. Machine output, room shielding and assigned procedures are identical to the earlier periods. Which conclusion about personnel dose and ALARA should the radiation safety officer reach from this report?
- During monthly linac QA, output constancy agrees with the previous baseline, MLC leaf positions sit within tolerance, and the isocenter lasers pass. The light field extends past the radiation field edge on both lateral sides beyond the applicable tolerance, while the longitudinal edges line up. What should the therapist do before the linac is cleared for patient treatments?
- During a review of a new treatment vault, the architect points out three areas: an east wall that can be struck by the useful beam at gantry 90°, a north wall several meters from the couch that never crosses the beam path, and a maze wall seen only around a corner from the target. Which classification correctly identifies the shielding basis for each area?
- A patient scheduled for MRI simulation before pelvic radiotherapy reports that he once ground steel without eye protection and may have had a spark reach his eye. He denies eye pain, sees normally, and his questionnaire shows no implants, pacemakers, or retained metal anywhere else. Which screening step must be completed before he is allowed into the magnet room?
- A radiation therapist declares her pregnancy in writing to the radiation safety officer, and her monthly badge readings will be reviewed for the rest of the pregnancy. The department must apply the correct limit to the embryo or fetus. Which dose limit governs the fetal exposure for a declared pregnancy?
- During a quarterly review, the radiation safety officer finds that a therapist's whole-body dosimeter reported zero dose even though the therapist covered treatment-assist shifts in the room every day. The badge had been kept inside a lead apron pocket, and the officer wants the therapist to monitor occupational exposure during these duties. Which personnel monitoring practice should the therapist follow when wearing the apron?
- Before the first patient of the day, a therapist walks a new hire through the morning routine: the linac warm-up runs first, then the daily output and mechanical checks are recorded, while the CT simulator check is handled separately. Which statement correctly describes what the linac warm-up accomplishes before those checks are documented?
- During monthly quality assurance, output lands inside the department's tolerance, the light and radiation field edges agree, and the MLC leaves verify, but the sagittal isocenter laser sits about 3 mm off the mechanical isocenter. Which corrective action is justified before the next patient is set up?
- A monthly output constancy measurement on the linac is outside the department's action limit but inside the manufacturer's service range. The physicist is on site, asks to be told immediately, and treatment is paused. Under the department's QA procedure, what should be documented before the machine returns to patient service?
- Before a planning MRI, a patient reports a medication patch on the upper arm, a stainless steel clip from an operation two years ago with the implant card available, and a grinding injury to the eye with no imaging on file. Which pre-scan hazard checks must be finished before this patient enters the MRI room?
- A student observing morning QA sees the accelerator's dose-monitor reading fall below tolerance while the CT simulator calibration, the light field, and the imaging panel all check out normally. Which accelerator component most directly supplies the signal behind this low reading?
- During a dosimetry review, a vault therapist tells her supervisor that she declared her pregnancy at 11 weeks of gestation. Her whole-body badge total for the year is 8 mSv, and the medical physicist asks the team to apply the correct fetal limit for the rest of the pregnancy. Which statement gives the correct NCRP-based dose limit for the fetus in this declared pregnancy?
- In the nuclear medicine hot lab, an unshielded multi-dose vial on the prep counter measures 60 mR per hour at 30 cm, and the survey at the lab doorway reads the same level. The adjoining corridor carries visitors and clerical staff all day. Which posting and survey routine correctly matches this lab's measured radiation level?
- Two lung plans deliver the same prescribed dose to the same small lung target, and the multileaf apertures are nearly identical, yet a plan quality check flags higher out-of-field dose in the plan with wider jaw openings. Which beam adjustment should be made to lower dose to healthy tissue while target coverage stays unchanged?
- During monthly output constancy QA, the team irradiates a water-equivalent phantom at the machine's reference geometry and compares the reading with the established baseline for that machine. The result must appear in the same session, be an absolute dose in cGy, and come from a detector suited to the beam energy. Which detector should the therapist use for the output measurement?
- A monthly constancy check on the treatment machine returns an ionization-chamber reading outside the tolerance listed in the department QA manual, and afternoon treatments begin in an hour. The therapist must decide what to record and who to tell. Which action correctly evaluates and documents this out-of-tolerance QA result?
- Concentric ring artifacts in a CT simulator image appear when one specific component drifts out of calibration, and the rings stay centered on the rotation axis throughout the reconstructed image. Which component generates this artifact pattern?
- A spot survey in the vault anteroom while the machine is running reads 0.6 rem accumulated in one hour at 30 cm from the accessible surface. The space is observed only intermittently while therapists walk in and out for setups. Which requirements govern how this anteroom is posted, entered and monitored?
- A shielding sketch for a new room built for a linac that rotates a full circle around the patient lists four surfaces: the wall opposite the gantry, the floor beneath the couch, the ceiling above the treatment position, and the door at the far end of the entrance maze. Which surface needs only scatter-and-leakage shielding?
- A patient reports a transdermal pain patch on the left shoulder that is labeled to contain metallic foil, a metal fragment that struck one eye years ago with no record of follow-up imaging, and an old hip implant whose paperwork was left at home. The technologist is completing MRI screening before the exam. Which safety steps must be finished before the patient enters the magnet room?
- During acceptance testing, a physicist must verify the linear accelerator's absolute absorbed dose to water under reference conditions, using a measurement traceable to a standards laboratory. The physicist asks which detector from the instrument drawer should be used. Which detector best satisfies that measurement requirement?
- A hospital is fitting out a vault for a 6 MV linear accelerator, and the physicist must classify the wall in front of the gantry, the side walls, the ceiling and the entrance maze before calculating thickness. Which statement correctly assigns the barrier type and design basis for each surface?
- A radiation therapist remains in the room during fluoroscopic imaging while wearing a wrap-around protective apron. The radiation safety officer issues one dosimeter to monitor exposure to the body parts outside the apron. Where should it be worn?
- Your independent check of an AP cervical spine plan finds the superior jaw 2 cm above the approved portal border, directly over the thyroid, while the inferior border sits exactly on the approved target margin and the monitor units match the plan. Department policy requires the delivered field to agree with the approved portal image before a fraction is treated. Which correction brings the field into agreement with the plan while keeping the prescribed target dose?
- At the start of a busy treatment day, the linac has been off overnight while the CT simulator has sat idle since yesterday. You are the first therapist in, forty patients are booked, and physics is unavailable until noon. Which morning sequence follows the applicable warm-up and daily QA procedures for both machines before they are used?
- A radiation therapist in her first trimester formally declares her pregnancy to her supervisor. She continues to run daily machine checks, position patients in the treatment room, and work at the console, and the department wants to keep her on the usual rotation. Which dosimetry practice best applies ALARA to her and the fetus during the declared pregnancy?
- During weekly QA on the treatment linac, film shows that the radiation field and the light field are the same size and shape, but the light field sits a few millimetres to one side of the radiation edge every time. The offset appears at every couch height and measurement distance, and the jaw settings match yesterday's record. Which component should be adjusted first to restore light and radiation field coincidence?
- The weekly output check on the treatment machine falls outside tolerance, and a repeat measurement confirms the deviation while the light field, MLC leaf positions, and isocenter lasers all pass. Which response to the failed output check must come before the first patient is treated?
- During MRI safety screening, a patient scheduled for a lumbar spine scan reports an MR-conditional spinal cord stimulator with its label checked, an insulin pump worn on the belt, and a nicotine patch on the upper arm. The slot is already running late. Which MRI safety actions must be completed before the patient enters the scan room?
- A radiation therapist at 14 weeks of pregnancy has formally declared her pregnancy and has a fetal dose of 0.3 mSv recorded for the past month, with shielding in place and the monthly badge readings verified. Which reference limit should this month's fetal dose be judged against?
- After the morning CT simulator warm-up and air calibration finish without error, the therapist runs the linac daily output constancy check and the reading sits outside tolerance for the second morning in a row. Which step in the daily quality-assurance routine should come next before any patient is treated?
Procedures: Treatment Sites and Tumors (11.5%) · 34 questions
- A breast core biopsy returns an invasive carcinoma with no special type. Microscopy shows tubule formation across about 40% of the tumor, moderate nuclear variation, and a moderate mitotic count, scored 2, 2, and 2 in the three-part grading system. Which histopathologic grade and type should be recorded for this tumor?
- During a planning conference the team reviews a core biopsy from a patient's breast mass. The pathology report identifies invasive carcinoma with tumor cells forming glands in part of the specimen, marked variation in nuclear size and shape, and frequent mitoses; the Nottingham score is 8 of 9 across its three features. Which statement correctly classifies this tumor's histologic type and grade?
- A patient treated for squamous cell carcinoma of the head and neck three months ago returns with worsening hoarseness and noisy breathing that eases when he sits upright. His arm and leg strength is normal, he swallows without difficulty, and his facial appearance is unchanged. The oncology team orders urgent radiation to relieve the blockage. Which anatomical obstruction is this emergency treatment intended to relieve?
- In the usual drainage pattern, a tumor in the upper outer quadrant drains through a predictable chain of nodal groups, and that quadrant has the densest lymphatic connection of any area of the breast. Which lymphatic drainage pathway is usually the first stop for cells leaving such a tumor?
- A patient with metastatic lung cancer is admitted with worsening leg weakness, and MRI confirms cord compression at an untreated thoracic vertebra. Steroids have been started, and the radiation oncologist wants the first fraction delivered today while the spine team decides on stabilization. Which treatment course should the department plan for this cord compression emergency?
- A patient with a mid-rectal tumor finishes chemoradiation and is booked for a posterior pelvis course. The target covers the mesorectum plus the nodal drainage that runs beside the pelvic sidewall vessels. Which lymphatic chain should be outlined as the nodal target for this site?
- A patient with adenocarcinoma of the mid-rectum is simulated prone on a belly board, and the physician's note states that the primary lesion sits above the dentate line and is confined to the rectal wall. The therapist is asked to confirm the nodal basin covered by the elective target volume. Which lymph node group is the first-echelon drainage for this mid-rectal tumor?
- A patient with diffuse large B-cell lymphoma has cervical and mediastinal node involvement plus splenic involvement, with no distant organ disease. The treatment plan needs a stage recorded under the current PET-CT-based consensus classification that revised the original Ann Arbor system. Which staging system applies to this lymphoma case, and what does its classification describe?
- A patient with known lymphoma is admitted with new leg weakness, saddle numbness, and inability to void, and MRI confirms an epidural mass compressing the spinal cord. The team wants radiation planning started today. Which reason justifies treating this spinal presentation as an emergency?
- A lung biopsy report describes malignant cells arranged in sheets with intercellular bridges and keratin pearls, and the physician wants the classification entered before planning begins. The team is deciding how the tumor should be labeled. How should this tumor be classified by type and grade?
- A radiation oncology team reviews the staging workup for a newly diagnosed follicular lymphoma. PET-CT shows disease in two contiguous lymph node regions on the same side of the diaphragm, with no marrow or extranodal involvement and no B symptoms. Which staging description correctly classifies this patient's disease?
- A punch biopsy from a lung lesion comes back describing malignant cells arranged in nests with intercellular bridges and focal keratin pearls, noted as moderately differentiated, with mitoses visible in several high-power fields. The staging conference needs this entered correctly in the treatment record. Which statement matches the tumor's histologic type and grade?
- A patient being treated for lymphoma reports new mid-back pain that began over two days, weakness in both legs, and difficulty starting urination. The physician is called to the department, and the team must identify what this finding represents. Which clinical urgency and next step match this presentation?
- A patient with a right upper lobe lung tumor is being staged, and the physician reviews the usual regional nodal drainage from this tumor location before planning the target volumes. Which nodal group is the best answer for the first-echelon regional drainage?
- A patient with newly diagnosed Hodgkin lymphoma has biopsy-proven involvement of a right cervical node and of the mediastinal nodes. PET-CT shows disease confined to lymphatic tissue, entirely above the diaphragm. Which Ann Arbor stage applies to this pattern of nodal spread?
- A breast core biopsy reports invasive ductal carcinoma with tubule formation under 25 percent, marked nuclear variation, and a high mitotic count, giving a combined Nottingham score of 8 out of 9. Which histopathologic type and grade should be entered in the record that the treatment plan references?
- At the initial planning conference, the team describes a patient with lymphoma involving nodal chains in the neck and around the abdominal aorta, a liver biopsy free of disease, and extranodal sites uninvolved. Which staging designation correctly classifies this patient's disease?
- During a simulation conference for a patient with a 3 cm invasive tumor in the upper outer quadrant of the left breast and no palpable adenopathy, the team must decide which nodal regions to contour on the planning CT. Which lymphatic drainage pattern correctly guides that contouring decision?
- A 62-year-old patient newly diagnosed with Hodgkin lymphoma has biopsy-proven cervical and retroperitoneal lymph nodes; the staging workup shows no extranodal organ involvement, and the patient reports no fever, drenching night sweats, or weight loss. Using the Ann Arbor system, which statement correctly explains this patient's stage classification?
- A pathology report on a resected mass describes malignant cells of epithelial origin arranged in solid sheets with no gland formation, marked variation in nuclear size, and mitotic figures in most high-power fields. The oncology team is completing the diagnosis summary for the treatment plan. Which histopathologic type and grade should be recorded?
- A patient is simulated for breast-conserving treatment of a 3 cm mass in the upper outer quadrant of the right breast, and the surgeon has documented a positive level I axillary sentinel node. The oncologist wants the first-echelon drainage basin confirmed before contouring. Which lymphatic drainage pattern should the team expect from this tumor?
- During review of a prostate plan, the physician notes that the highest posterior dose lands on a hollow pelvic organ and asks the planner to pull up its dose-volume limits for late toxicity. Which organ should be evaluated for those limits?
- A patient who had a testicular tumor removed is simulated for irradiation of the nodal drainage area, and the therapist checks that the field boundaries match the first-echelon nodes for this site. Which nodal region receives the primary lymphatic drainage from the testis?
- Breast lymph drains from the tissue into nodal basins, although individual drainage pathways can vary. For a cancer in the upper outer quadrant, with the skin clear and the opposite breast unaffected, which nodal group is the usual first-echelon drainage site for that tumor?
- A woman completes breast-conserving therapy for a lesion in the medial quadrant of the breast. Because the nodal regions at risk depend on which quadrant drains into which basin, the oncology team reviews the lymphatic pathway before discussing regional nodal coverage. Which nodal chain receives lymph directly from the medial quadrants of the breast?
- A patient admitted with a swollen face, distended neck veins and breathing discomfort is found to have a large mediastinal mass compressing the superior vena cava. The oncology team calls the department to arrange treatment today. Which treatment approach reflects the emergency intent of this referral?
- A female patient is simulated for treatment of the cervix, and the therapist outlines organs at risk on the planning CT before the plan is scored. Which relationship between the cervical target and the nearby pelvic organs is correct on axial images?
- A biopsy confirms a 4 cm adenocarcinoma of the colon. The primary has grown through the muscularis propria into the surrounding pericolorectal fat, the serosa is intact, and no adjacent organ is involved. One regional lymph node contains metastatic tumor, and imaging shows no distant spread. Which TNM classification fits these findings?
- During image review for a prostate treatment, the therapist traces the target against its neighboring pelvic organs and must name the organ directly behind the prostate for the setup notes. Which structure lies immediately posterior to the prostate?
- A patient with metastatic lung cancer returns for planned palliative treatment of a painful vertebral metastasis and reports that back pain like last month's has returned, but this time with new leg weakness and difficulty passing urine over the past day. Which approach correctly matches treatment urgency to this presentation?
- A patient with known metastatic disease develops new leg weakness and urinary retention over two days, and MRI shows a mass pressing the spinal cord at T10 with vertebral height preserved. Pain is controlled with medication. Which radiation indication and timing best match this presentation?
- A patient is simulated for an upper abdominal treatment with daily portal imaging, and the physician wants a landmark that holds the same position between fractions so image matching stays reliable. Several organs appear in the same image. Which upper abdominal organ best serves as the stable retroperitoneal landmark?
- A biopsy of a lung mass is read as nests of malignant epithelial cells with intercellular bridges and abundant keratin pearls, and the pathologist notes that keratin production dominates the specimen. Which histopathologic type and grade does this description support?
- A patient with a 3 cm cancer in the upper outer quadrant of the right breast is simulated for whole-breast treatment with regional nodal irradiation. The physician asks the therapist to explain why the contoured nodes are on the right side of the chest. Which lymphatic drainage pathway most commonly accounts for the first-echelon nodal target?
Procedures: Treatment Volume Localization (10%) · 30 questions
- A patient with an oropharyngeal tumor needs six weeks of daily IMRT, has limited neck extension from arthritis, and cannot raise his arms above his head after shoulder surgery. Which immobilization setup best keeps his position reproducible from day to day?
- A patient with a large pendulous breast is booked for whole breast irradiation after lumpectomy. Shoulder stiffness makes a supine arms-overhead position uncomfortable, she cannot sustain a reliable breath hold, and the inframammary crease forms deep skin folds. At simulation, she can tolerate the supported arm position available on a prone breast board. Which treatment position and immobilization best meet her setup needs?
- A patient with painful bone metastases in the thoracic spine can lie only partially reclined; lying flat brings sharp pain within a minute. Ten palliative treatments are planned, and the same setup must be reproduced at each visit. Which positioning and immobilization approach best fits this treatment?
- A patient with a laryngeal tumor is simulated for an opposed lateral setup. The neck must stay extended so the mandible and cervical spine clear the target, the shoulders must stay below the field borders, and the head and neck must sit in the same place every day. Which positioning and immobilization arrangement best meets these localization requirements?
- A patient with a lower-lobe lung tumor is booked for simulation. The tumor moves noticeably with each breath, and the patient struggles to follow coached breath-hold instructions. CT simulation with breathing-motion imaging is available, while these machines cannot deliver respiratory gating. Which simulation, positioning and immobilization approach best accounts for the target's motion?
- A patient with laryngeal cancer is simulated for a matched midline neck field. The superior border reaches the skull base, and both shoulders must sit in a fixed, repeatable position clear of the lower border at every fraction. Which immobilization setup best reproduces this treatment position?
- A planning CT is being simulated for an abdominal target that sits against loops of small bowel, and the radiation oncologist wants the bowel lumen clearly visible on every slice for contouring. Which imaging preparation should be used before the scan to outline the bowel?
- At CT simulation, the therapist sees that small bowel loops sit directly against the pelvic target and are hard to separate from tumor. The physician orders an oral iodinated solution for the patient to drink one hour before the scan and asks for a simple explanation to give. Which purpose does the oral contrast serve on this planning CT?
- A patient drinks oral contrast before a pelvic CT simulation, and axial images show bright rounded structures low in the pelvis. The therapist must confirm these are bowel loops before the physician contours the target. Which sectional anatomy finding identifies them as bowel?
- A patient with a T2 glottic laryngeal cancer is simulated on a planning CT with IV contrast, so vessels enhance while the aerodigestive tract stays dark. On an axial slice at the level of the vocal cords you must identify the tube lying directly behind the tracheal air column before labeling the structures on the image. Which structure occupies that position, based on its relationship to the trachea?
- During a simulation CT of the upper abdomen, images are acquired with IV contrast in the portal venous phase. A 3 cm mass lies posterior to the peritoneal cavity, adjacent to the right kidney and psoas muscle, while nearby bowel loops lie anterior to it. Which localization of the mass best fits these anatomic relationships?
- During a pelvic simulation, the physician needs the loops of small bowel sitting above the bladder to stand out clearly on the axial CT slices so they can be separated from the target. The patient drinks comfortably and the department has cleared them for contrast. Which contrast approach best makes those bowel loops visible for contouring?
- A patient with a 3 cm tumor in the right lower lobe is simulated for stereotactic treatment, and fluoroscopy shows the lesion moving almost 2 cm with quiet breathing. The department can offer either a standard helical scan or a gated study, and the physicist needs the motion extent documented before contours are drawn. Which CT simulation acquisition best records the tumor's motion range for planning?
- A patient with a lung lesion that travels several centimeters with breathing is simulated for a stereotactic course; immobilization is set, the scanner can sort by respiratory phase, and the physician wants the motion characterized. Which CT acquisition approach best captures the target motion for planning?
- A patient with a lower-lobe lung tumor is simulated with a 4D CT for a motion-managed plan. On review, the breathing trace varies from cycle to cycle, and in several bins slices are missing across the tumor, which reaches the edge of the scanned volume at full inspiration. Which acquisition change best addresses both causes of incomplete respiratory bins on the repeat scan?
- A patient is simulated supine with both arms raised for a boost to a 1.4 cm supraclavicular target. The department's default planning CT uses 5 mm slices, and the radiation oncologist wants the target and its junction with the prior neck fields contoured on the same dataset. Which CT acquisition parameter should you adjust for this simulation?
- A patient with a right lower lobe lesion is being simulated for photon treatment, and the planning CT shows the lesion moving with quiet breathing. Immobilization and the scan range are already verified, and the physicist wants the full motion extent captured before contouring begins. Which CT acquisition approach will capture the full motion extent the physicist needs?
- A patient with a peripheral right lower lobe tumor is simulated for stereotactic lung treatment, and scout images show the mass moving several millimeters with each breath. The team must choose an acquisition that captures this motion for treatment planning. Which CT simulation acquisition best represents this respiratory motion for treatment planning?
- The bladder has been outlined on every axial slice of a pelvis CT taken at a fixed slice interval, with each outline's area stored on the workstation. The reported volume must account for every outline that was drawn. Which calculation gives the contoured bladder volume?
- During a CT simulation of a pelvis plan, the target is contoured on every axial slice, but the crosshair on the coronal reconstruction sits close to the superior edge of the volume. Which check confirms the isocenter before skin marks are made?
- A physician contours a lung lesion on the simulation CT, and the record must show each target volume as a separate structure for review. The plan has to cover microscopic spread beyond the visible lesion and absorb day-to-day setup variation. Which contour sequence correctly defines the volumes used for the dose plan?
- A pelvis planning CT was reconstructed at 5 mm spacing instead of the 3 mm spacing required by the simulation protocol, so the contoured target volume differs from the physician's estimate, and the isocenter sits at the center of the largest axial slice. Which corrections must be completed before the plan is calculated?
- During CT simulation for a pelvic plan, the radiation oncologist places a reference point in the middle of the target on the axial images. The patient will be set up daily with room lasers, and that point must be reproducible at every fraction. How should the therapist transfer the reference point and document it?
- After CT simulation of a pelvic target, the physician draws the target volume on the axial images and specifies that the isocenter should be at its center. Your workstation shows linked axial, sagittal, and coronal views with a movable crosshair. You must document the isocenter in the simulation note before the plan moves to dosimetry. How should you place and verify the isocenter relative to the contoured volume?
- After CT simulation for a head-and-neck case, department protocol requires four items in the record: verified skin marks, approved set-up photographs, written immobilization instructions, and a note on electronic device precautions. The planning team starts as soon as the therapist closes the session. Which documentation set most fully completes the simulation record?
- A head-and-neck patient finishes CT simulation in a thermoplastic mask with skin marks drawn and a set-up photograph taken, and the patient's wearable glucose monitor must be off at every visit. The record must let the next therapist confirm marks and photo, reproduce the position, and repeat the device step. Which record entry completes all three documentation requirements?
- Following a CT simulation, the therapist has saved two setup photographs, recorded skin marks, written set-up instructions, and a note describing how the patient's wearable electronic device was handled. A colleague will build the plan from this record tomorrow morning. Which verification confirms that the simulation documentation agrees with itself before planning begins?
- After CT simulation for an abdominal patient, a second therapist will run the daily treatments from the saved plan, and the scan plus setup photographs are already filed. Which detail must be written into the setup instructions to reproduce the position every day?
- Before a treatment plan is built, you check the simulation packet for a patient who has just finished her CT scan. The written setup sheet lists the immobilization device, her arms raised on the armrest, and the skin mark locations, but the setup photograph shows her with the device removed and her arms at her sides. The photograph is intended to document the treatment setup. Which documentation correction should be made before the packet is released for planning?
- After a CT simulation for a patient treated prone on a breast board, the record shows documented skin marks and four saved setup photographs, but the written setup note says only 'prone with the board in use.' Which update to the simulation documentation is needed before the plan is reviewed?
Procedures: Prescription and Dose Calculation (10.5%) · 31 questions
- A pelvic target is planned with opposed anterior and posterior fields to a prescription point at midplane, with both fields the same size and the same machine settings. The plan gives 26 Gy from the anterior beam and 24 Gy from the posterior beam at that point over the full course, and the two must still sum to that course total. How should the two fields be weighted so each one contributes the same dose at midplane?
- For an isocentric treatment delivered at a 100 cm source-to-axis distance, the target lies 12 cm below the skin on the central axis, and the beam shaping gives a 15 × 15 cm field at the isocenter of a 6 MV beam. Which quantity should supply the depth dose factor used in this calculation?
- On a 6 MV unit, the skin surface sits 15 cm farther from the source than the nominal setup distance, the target lies 4 cm off the central axis at a depth of 12 cm, and the dose is prescribed to that point. Which set of corrections must be applied to this field's monitor units?
- A post-mastectomy chest wall plan uses a 6 MV beam with a physical wedge, a cerrobend block mounted on the tray, and daily bolus over the scar. The open-field output factor was measured in water for the same field size, and the tray/block and bolus effects are accounted for separately. Which correction accounts for adding the wedge when determining the wedged-field central-axis output?
- While reviewing a simulation for a lung primary you see a GTV on the visible tumor, a CTV adding microscopic spread, an ITV growing and shrinking with breathing, and a PTV adding setup margin. Which prescription volume must receive the prescribed dose at every fraction?
- Before the first fraction, a colleague asks you to verify the monitor units for a new 6 MV plan. The chart lists the prescribed dose at the target, the target depth, the field size and the distance from the source for the setup. Which recalculation confirms that the monitor units match the prescription?
- A 6 MV beam treats a mediastinal target through a physical wedge, a tray-mounted block, and chest wall bolus, with the wedge and tray output factors already applied. An ion chamber beyond a low-density lung region, where primary-beam transmission dominates, reads higher than the homogeneous water calculation predicts. Which dose calculation factor explains the higher reading?
- The linac is calibrated for a 100 cm source-to-skin distance, but a thick immobilization vest places this patient's skin at 118 cm for a target that sits on the central axis at 6 cm depth. Monitor units were copied unchanged from a nominal-distance plan. What should the physicist do before treatment?
- A patient is treated isocentrically at SAD 100 cm with a whole-brain field matched to a posterior spine field. Both fields have a half-beam blocked edge at the junction, and the physicist marked the projected junction line on the skin. The therapist checks the light field before the first fraction. Which check confirms that the projected field edges align at the skin mark?
- During a chart review you find a four-field pelvic plan prescribed to 60 Gy at the isocenter, with beam weights listed as AP 0.4, PA 0.4, right lateral 0.1 and left lateral 0.1. The physicist notes that every weight is referenced to the isocenter dose. Which statement correctly describes what these weights control in the plan?
- On the planning CT, the team contoured the visible mass, expanded it 8 mm for possible subclinical disease, added the full breathing motion envelope, and then added setup uncertainty. The prescription delivers 50 Gy in 25 fractions to this final contour. Which target volume does the final contour represent?
- A 6 MV plan delivers the prescription to a midline target at 10 cm depth with a 10 x 10 cm open field and 180 monitor units. The physician then widens the treatment field to 20 x 20 cm at the same energy and depth, and the record-and-verify entry still shows 180 monitor units. Which beam parameter must be recalculated before the plan is approved for treatment?
- During the final check of an isocentric 6 MV plan, the isocenter sits at the standard 100 cm source-to-axis distance and 6.0 cm deep in the target, the prescription is 200 cGy at that point, the beam is open with no wedge, and the MLC shapes the aperture. The machine output for this aperture is 1 cGy per monitor unit at the calibration depth of maximum dose. Which calculation best verifies the monitor units for this beam?
- A pelvis case is planned on a 6 MV linear accelerator with the target sitting on the rotation axis at the machine's stated distance, and the gantry travels an arc around that fixed point. The monitor units were written for the axis depth rather than for the skin entry point. Which depth-dose quantity should verify these monitor units for this isocentric setup?
- A long treatment volume must be covered by two adjacent photon fields matched over the thoracic spine. Simulation shows beam divergence shifts the two edges past each other at the target depth, so the physicist recommends half-beam blocking at the junction line. What function does the half-beam block serve for the abutting fields?
- A patient is treated on a setup where the entry surface slopes, so tissue thickness varies across the treatment area. The physicist wants the dose at the prescription depth to be uniform across the field while the beam arrangement and field size stay unchanged. Which beam modifier best accomplishes this?
- During plan review at a regional cancer center, a therapist reads the written prescription for a lung primary: a radical course of 6 MV photons given in daily fractions to a named target volume, while the plan summary lists the dose to a different volume. Which volume must be verified to confirm coverage of microscopic disease plus setup and breathing margins?
- Before the first fraction of a chest wall plan you check the printout and find four modifiers: a physical wedge, an accessory tray, a bolus sheet over the scar, and lung in the beam path. Each one should have been handled in the prescribed dose calculation. Which statement correctly describes how these four modifiers affect the dose at the treatment site?
- During peer review of a lung plan, the physicist notes that the evaluation structure was built from the microscopic disease volume and then expanded for setup uncertainty and respiratory motion. The physician asks which prescription volume the plan should be judged against. Which target volume is being described?
- Two adjacent fields abut along a junction marked on the upper chest of a patient who is set up for treatment. The plan uses half-beam blocking so each field edge sits at its own central axis, and the therapist must confirm the match before treating. Which measurement verifies that the two field edges abut without overlap or gap?
- A patient with a large anterior-posterior separation needs a photon field set at SSD 118 cm rather than the usual 100 cm, keeping the same field size at the skin. For the geometric inverse-square correction to the primary fluence at 7 cm depth, which factor gives the dose per monitor unit at the extended SSD relative to the usual SSD?
- A 6 MV anterior field treats a pelvic target at 100 cm SSD with a wedge in place. The prescription is 200 cGy at a depth where the wedged beam's percent depth dose is 80.0%, the 15×15 cm open field has an output factor of 1.050, and the measured wedge factor is 0.700. The unit delivers 1.00 cGy per MU at reference conditions. Which monitor unit value delivers the prescription dose at that depth?
- A 6 MV beam is planned for an isocentric pelvic treatment at 100 cm SAD, with the target centered 9 cm deep at the isocenter, and the skin surface sits at a different distance for each patient. The physicist needs a depth ratio that holds no matter where that surface sits. Which dose ratio should express the depth effect for this isocentric geometry?
- A palliative plan for a sternum lesion is prescribed as 2 Gy per fraction at the midplane, and the plan record explicitly defines the anterior field weight of 1.5 and posterior field weight of 0.5 as normalized dose contributions to that prescription. During the check a therapist asks how those weighting numbers translate into the daily dose. Which dose split between the two fields does that notation describe?
- A course is prescribed as 54 Gy in 30 fractions with a midline normalization and a 3:1 weighting favoring the right lateral field. The two lateral fields enter at different depths and use different MLC aperture sizes, so their beam settings are not comparable. Which statement correctly interprets the 3:1 field weighting in this prescription?
- A 6 MV isocentric pelvis plan puts the isocenter at 10 cm depth, and the physicist wants one beam-data quantity that stays valid as patient thickness changes the SSD from fraction to fraction, with all beam data collected while the detector stays in the water phantom. Which depth-dose quantity should you use to verify dose at the isocenter?
- A patient who cannot be raised to isocenter is treated at an extended SSD of 115 cm for a parallel-opposed abdominal field; the chart lists an 18 x 20 cm field and a midplane depth of 14 cm. At what distance from the source should the light field be measured to verify the stated size?
- A therapist verifies the light field during setup for an isocenter-based treatment with a 100 cm source-to-isocenter distance. The chart lists a nominal 10 x 10 cm field at the isocenter, the central-axis target depth is 10 cm, and a ruler on the patient's skin shows about 9 cm between the light-field edges. Which statement correctly explains the skin measurement?
- A head and neck patient is treated on a 6 MV linac, and today's setup places the skin at an extended 115 cm SSD because the shoulder immobilizer raises the treatment level. The target depth, the field size at the skin, and the beam energy all match the plan calculated at the nominal 100 cm SSD, no wedge or tray is in the beam, and the target sits on the beam axis. Which correction must be applied to the prescribed monitor units for this extended-distance setup?
- A lung prescription reads 60 Gy in 30 fractions with 6 MV photons, and the plan defines GTV, CTV, ITV, and PTV structures. The physician wants the structure that already accounts for breathing motion but excludes the setup margin. Which target volume matches that description?
- A plan for a lung target was calculated on a water-equivalent phantom. On review you note that the beam crosses a low-density lung segment, uses a physical wedge with its tray mounted, and passes through bolus over the entry skin. Which statement correctly describes how each element changes the dose relative to that calculation?
Procedures: Treatments (19%) · 57 questions
- A post-mastectomy patient receives a 6 MV field to a superficial chest wall target that reaches the skin, and the plan's MLC leaves already match the target outline. In vivo measurements put the surface dose well below prescription while the reading at 1 cm depth is on target. Which beam modifier should be used to bring the skin dose up to prescription?
- A patient with head-and-neck cancer is simulated for a course covering the cervical nodes that will repeat daily for several weeks. The patient cannot keep both arms raised for more than a few minutes and reports neck pain whenever the head turns to the side. Which immobilization setup should be chosen for reproducible daily positioning?
- A 70-year-old with a localized 3 cm lung tumor and severe COPD is judged unfit for surgery, and staging shows no nodal or distant spread. Which treatment approach best matches this patient's localized, inoperable disease?
- On the fourth fraction of a chest plan, record-and-verify confirms that monitor units, beam energy and gantry angles match the approved plan for every field, and earlier daily images aligned well. The current image registered to the planning CT shows the target about one cm superior to its planned position, with the beam still off. Which verification step should complete this setup before the fraction is delivered?
- A patient with a small peripheral lung lesion that moves with breathing is scheduled for a short high-dose course. The plan must shape dose tightly around the target, account for respiratory motion, and include a volumetric image check every treatment day. Which treatment and imaging combination satisfies all three requirements?
- A patient receiving pelvic radiotherapy lines up on the tattoos and wall lasers, yet daily cone beam CTs show a different 5 to 8 mm error with each therapist. The knee sling, foot plate, and table index are set by eye each morning rather than locked to recorded positions. Which correction will most reliably restore this patient's setup reproducibility?
- A patient is positioned for a lateral head-and-neck field, and the tabletop edge would clip the beam at the planned gantry angle. The therapist plans to adjust the couch before the first fraction without disturbing the tattooed setup. Which couch adjustment keeps the beam clear while the patient stays at isocenter?
- You are at the console monitoring a treatment fraction when the patient on the couch grows pale and clammy and tells you over the intercom that the room is spinning. Within a minute her replies turn slow and groggy, and the camera view is partly blocked so you cannot tell whether she is still responding. Which immediate response should the therapists take to manage her decreasing alertness during treatment?
- A pancreatic tumor shows about 2 cm of craniocaudal motion on fluoroscopy, and the patient cannot sustain a breath hold because of chronic lung disease. The plan must keep motion small and tie beam delivery to a reproducible respiratory phase. Which motion-management approach meets the motion and phase requirements?
- A therapist covering three rooms reads a conditioning treatment before a stem cell transplant, an electron treatment across the entire skin surface, and a photon course to a lung primary. Which pairing of technique with clinical purpose is accurate?
- While a postoperative chest wall field is being delivered, the linear accelerator stops mid-fraction and the console shows an unfamiliar error code. The record system indicates that part of the planned monitor units has been given and the patient is still immobilized on the couch. Which steps and record entries follow this equipment malfunction?
- A patient receiving pelvic treatments has a knee that stays bent and a pelvis that keeps sliding toward the foot of the table during each fraction. Which combination of positioning aids should the therapist set up to support the knee and limit pelvic movement?
- A patient with a superficial chest wall lesion is planned for photon treatment, and the physician wants the dose at the skin surface to reach the prescription level instead of falling in the build-up region. Which beam modifier should be added to the treatment set-up for each fraction?
- Halfway through an upper abdomen fraction, the patient on the couch, drowsy from premedication, suddenly begins to retch and vomit while the beam is running and you are alone at the console. Which immediate response best protects a patient who vomits during treatment?
- A patient with a small, localized stage I non-small-cell lung cancer that has grown on recent imaging is medically inoperable because of cardiopulmonary disease. Which management approach best fits this patient's tumor and medical fitness?
- A daily CBCT is acquired for a pelvic treatment, and the automatic match proposes a large longitudinal shift. The sagittal view alone looks convincing, but the axial slices show the femoral heads rotating out of alignment. Which verification confirms that the registration is valid before the beam is delivered?
- A patient is being set up for a posterior oblique chest field, and the plan calls for the couch top rotated 30° so the rails clear the beam at a 315° gantry angle. The collimator must stay at 0°, and the isocenter has to remain at the same point in the patient after the rotation. Department protocol requires image guidance, not surface imaging alone, to verify internal position after couch rotation. Which couch and console checks confirm the setup before the beam is delivered?
- A patient receiving daily pelvic radiation is set up on a four-field plan whose approved record places the treatment isocenter 1.5 cm anterior to the skin mark. Today's orthogonal images show the target 0.5 cm lateral to that planned point, and a couch shift is applied. Which verification step confirms that the corrected setup now treats the planned isocenter?
- A patient is being set up for chest wall irradiation after a mastectomy. The physician requires that the dose at the skin surface match the prescribed depth dose, and the scar lies over a curved, uneven contour that the beam must follow. Which accessory best satisfies both the surface dose requirement and the contour requirement?
- Midway through an afternoon fraction the linear accelerator drops the beam and shows an interlock that does not clear when it is reset. The patient is unharmed and still positioned on the couch, and department policy requires that the cause be established before treatments continue on that unit. Which action satisfies the required response to this equipment malfunction?
- During orientation, a student reads four course descriptions from the schedule: a larynx photon plan, a total skin electron course for cutaneous lymphoma, a total body irradiation conditioning plan, and a temporary implant left in a cavity overnight. Which statement correctly matches each technique to its treated volume and where its source sits?
- A patient begins chest wall treatment with a field reaching toward the axilla. Both arms must be raised out of the beam and placed the same way each day, and tight hamstrings keep the patient from lying with straight legs. Which combination of positioning aids best satisfies these requirements?
- A patient returns for a boost fraction after the plan was revised earlier in the week, yet the record-and-verify system still has the original plan loaded for today's slot, while the printed summary in the chart shows the revised dose and new isocenter coordinates. Which verification step should be completed before the beam is enabled?
- A patient with a peripheral lung lesion that moves with breathing is being set up for stereotactic treatment on a linac. The team wants a volumetric check of the tumor's soft-tissue position immediately before beam-on every fraction, with imaging dose kept as low as reasonably achievable. Which imaging modality best meets that daily localization requirement?
- At simulation, a patient having treatment to the chest wall can hold both arms overhead only briefly, and with the arms at the sides the upper arms fall inside the planned beam paths. The setup must reproduce the same shoulder angle every day for the whole course. Which arm-positioning approach best fits these requirements?
- A boost plan is approved for a patient whose machine, immobilization device, and prescription are unchanged from the original course. The approved plan calls for a posterior isocenter shift of 1.5 cm, while the treatment record still shows a shift value of 0.0 cm. Which setup parameter must be entered and verified against the approved plan before the first boost fraction?
- Midway through a chest fraction, the patient on the table turns pale, sweats heavily, and reports feeling faint; the physician is down the hall and the emergency cart is outside the vault. Which immediate response best manages the deteriorating patient while help is on the way?
- A woman with a 3 cm, biopsy-proven, node-negative invasive breast carcinoma wants to keep her breast, and the surgeon confirms the lesion can be removed with clear margins. The tumor board also wants the lowest achievable local recurrence while the breast is preserved. Which treatment plan best delivers breast conservation, clear margins, and the lowest local recurrence?
- During a fraction a service error stops the linear accelerator partway through an arc, leaving the patient positioned on the couch while the console shows the fault message. Policy allows the beam to restart only after the physicist clears the unit, and the treatment record must show what actually delivered. Which response completes the equipment malfunction procedure?
- A liver SBRT patient has target motion larger than the 5 mm setup margin, breath-holds run out before the beam time ends, and the abdominal compression plate is painful over the treatment site. Respiratory gating with an external breathing surrogate is available. Which motion-management method best matches this patient's stated limits?
- On a busy day the schedule includes a pre-transplant whole-body treatment, a skin-wide electron treatment for a widespread superficial condition, a temporary cavity implant, and a conventional localized external beam. The team briefly disagrees about which description belongs to the skin-wide treatment. Which description correctly identifies total skin electron irradiation?
- Midway through a thoracic fraction, an elderly patient suddenly becomes short of breath, reports sharp chest pain with each breath, and the oxygen saturation starts falling. Which immediate response to this acute breathing emergency should the treatment team take?
- For a lung patient, the plan's registration instructions specify matching the tumor's soft-tissue edge on each daily image, but the automated match this morning locks onto the spine. Which check best validates the registration before the beams are treated?
- During setup for a supine spine field, the image shows the jaw edges running about ten degrees off the patient's spine, while the isocenter sits on the target and the beam must enter from the planned direction. Which single control change lines the field edge up with the spine?
- During fraction 14 of a lung boost course, the record-and-verify screen still shows the original 200 cGy dose and the old isocenter even though yesterday's revised plan was approved at 180 cGy with a shifted isocenter, and on-treatment imaging matches the new target. Which step confirms the plan version, isocenter, and dose before the beam is released?
- A tumor board reviews a 61-year-old with a 2.4 cm, node-negative, hormone-responsive breast tumor who hopes to keep the breast, and the team weighs surgery, radiation and systemic therapy. Which comparison of these options best supports recommending breast-conserving therapy for this patient?
- A patient with a lung tumor that shifts with breathing completed a 4D CT simulation, and fiducial markers are unavailable. Each day the team must confirm the soft-tissue position of the moving target before treatment. Which imaging approach best satisfies this daily localization requirement?
- During an arc treatment, the beam shuts off and the console shows a delivery fault before the planned monitor units are reached. The patient remains immobilized on the couch while the therapists decide how to respond. Which response correctly handles and documents this equipment malfunction?
- A patient in a thermoplastic mask is set up for a head-and-neck fraction, but a comfort adjustment leaves the skin marks misaligned with the room lasers. The console parameters match the treatment chart, and policy requires the isocenter to be confirmed against the simulated position before beam-on. Which verification step should the therapist complete first to confirm the isocenter?
- A plan-review worksheet lists three courses: course A gives electron treatments across the whole skin surface, course B gives fractionated irradiation to the whole body, including the lungs, liver and marrow, as transplant conditioning, and course C places an internal source in a surgical cavity. Which course should be labeled total body irradiation?
- A post-mastectomy patient is treated on a 6 MV linac with tangential fields at a fixed 100 cm SSD. Planning shows an even profile across the chest wall, but the buildup region leaves the dose at 3 mm depth well below the prescription, and the physician wants that superficial layer covered from the medial edge to the lateral margin. Which beam modifier should be added to bring the prescribed dose to the superficial chest wall layer?
- A patient receiving abdominal SBRT uses an abdominal compression plate because free-breathing motion was 14 mm at simulation. Marks, couch index, and isocenter were all set with compression at the recorded plate setting. At fraction one, the therapist aligned the tattoos to the lasers before applying compression, and the pre-treatment image showed the target 6 mm off. Policy requires imaging to serve only as confirmation of the setup. Which change to the abdominal compression setup sequence should be made first?
- A patient with a lung lesion is scheduled for stereotactic treatment in three fractions, and the lesion moves noticeably with breathing near the chest wall. The department offers kV cone-beam CT, MV portal imaging, kV orthogonal pairs, and surface-guided optical tracking. Which imaging method best confirms that this patient's lesion sits in the planned position before each fraction?
- A 52-year-old with a 3 cm biopsy-proven tumor confined to the primary site and regional nodes meets the surgeon, radiation oncologist, and medical oncologist at a multidisciplinary clinic, and each recommends a different approach. Which statement correctly describes the reach of surgery, radiation, and systemic therapy for this disease?
- During an afternoon fraction the treatment couch stops mid-travel and stays stuck, so the setup is finished manually and the beam is delivered. The physicist resets the machine and asks for a record of the event before the next patient is treated. Under the department's procedure, which requires documenting such events in both the treatment record and equipment log before the next patient, which entry most completely documents this equipment malfunction for the session?
- A patient with limited shoulder motion is scheduled for a chest treatment that was planned with both arms raised above the head. The therapist must keep the treatment volume aligned with the plan while the patient lies still for fifteen minutes. Which immobilization and positioning setup should be selected for the daily treatment?
- During setup for an anterior neck field, the light-field edge falls 1 cm short of the skin mark in the side-to-side direction even though the jaw-defined field size and collimator angle match the plan. Which machine control should the therapist adjust first to place that edge on the mark?
- A patient treated for an upper abdominal tumor shows more day-to-day shift in the anterior-posterior direction than expected even though the skin marks match the lasers. The department has indexed couch positions, surface-guided cameras, respiratory gating and an abdominal compressor. Which setup aid should you standardize and document first to reduce this variation?
- A patient with high-risk leukemia is scheduled for allogeneic stem cell transplantation. The prescription lists whole-body photon treatment delivered in two fractions per day with lung blocks, to be finished the day before the stem cells are infused. Which treatment technique does this prescription describe?
- A spine patient's plan calls for a couch shift of 1.0 cm superior and 0.5 cm toward the patient's right after verification imaging, and the record lists beam energy, field size, and monitor units for each beam. The patient is already aligned with the immobilization device and skin marks. Which pre-treatment verification covers every item stated for this fraction?
- A patient with a localized tumor asks the radiation therapist during setup how radiation differs from the surgery the oncologist mentioned and the systemic therapy other patients receive. The therapist keeps the answer accurate and general, centered on how each treatment reaches the tumor and the rest of the body. Which comparison correctly describes how each option acts on the disease?
- On the third fraction of a prostate treatment, today's image shows the same small offset of the target from the reference image that appeared on fractions one and two. The therapist is ready to treat and wants to keep the session moving. Which image-guidance check must be completed before beam-on for this fraction?
- During a lung treatment the patient signals through the intercom that they are suddenly very short of breath, and when you enter the room you find them coughing hard, pale, and slightly blue around the lips with about half of the fraction delivered. You are trained in basic life support. Which immediate response should the therapist take when breathing distress appears mid-fraction?
- A patient with widespread cutaneous T-cell lymphoma has plaques covering the trunk, arms, legs and scalp, and the oncologist wants a radiation option that treats the whole skin surface while keeping the dose shallow so deeper organs are spared. Which treatment option best fits that description?
- During plan review, an oblique photon field to a patient's sloped shoulder shows a hot spot on the crest and a cold band below it, with the isodose lines running diagonally across the target. Which beam modifier can correct this dose distribution?
- Daily imaging on a pelvic plan shows the target sitting superior to the planned isocenter. The physician approves a superior correction, and the shift is documented on the setup note while the patient stays on the couch. Which console operation should you perform to deliver this approved correction?
- A patient with a lung lesion that moves with breathing is set up for stereotactic treatment. The department offers daily orthogonal kV imaging, MV portal images of the treatment fields, and CBCT, and the lesion sits away from any fixed bony landmark. Which imaging strategy best verifies the target position for each fraction?
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