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?

Record-and-verify confirms machine parameters against the approved plan, so matching monitor units, energy and gantry angles addresses only part of verification. Geometry is the other part: image registration compares today’s anatomy with the planning CT, and the target’s superior shift matters. Correct the setup using the registered image, then re-verify site and dose so both plan values and position are checked before delivery. Treating the fraction as planned because the machine settings match leaves the visible geometric mismatch unaddressed; those settings do not establish where the target sits. Applying the couch shift and delivering right away skips confirmation that the corrected position agrees with the approved plan and dose. Returning the patient to simulation to rebuild the plan is not warranted by a single mismatched image alone; if the discrepancy persists or suggests an anatomy change, follow departmental procedures and consult the appropriate clinician. Small daily variations may be managed within departmental action thresholds, so know the tolerance your department uses before escalating. Practical check: confirm that both the plan values and image alignment were verified after the final position was set.