A patient with raised parathyroid hormone and hypercalcemia has a negative neck ultrasound but is booked for a minimally invasive parathyroidectomy. The surgeon needs the overactive tissue located in three dimensions, covered down into the chest, and distinguished from the thyroid. Which parathyroid localization plan meets those requirements?
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Short Explanation
You can distinguish the overactive parathyroid tissue from the thyroid with dual-tracer subtraction using sestamibi and thyroid-seeking pertechnetate. Add SPECT/CT of your neck and chest for a three-dimensional surgical map that can include ectopic tissue below the neck.
Full Explanation
Dual-tracer Tc-99m sestamibi/pertechnetate subtraction with SPECT/CT covering the neck and chest meets all three needs: subtraction helps distinguish hyperfunctioning parathyroid tissue from thyroid activity, SPECT/CT provides three-dimensional localization, and chest coverage can reveal ectopic tissue below the neck. Dual-phase planar sestamibi views of the neck and chest can use tracer washout, but planar images do not provide tomographic three-dimensional localization or reliable depth information. Early sestamibi SPECT/CT of the neck and chest provides three-dimensional anatomy and broad coverage, but without thyroid subtraction, thyroid activity can make the adenoma harder to distinguish. Early and delayed sestamibi SPECT/CT with thyroid subtraction offers thyroid separation and three-dimensional localization, but neck-only coverage can miss an overactive gland in the chest. An exam caveat: a negative ultrasound does not exclude primary hyperparathyroidism or an ectopic adenoma; localization imaging guides surgery rather than establishing the biochemical diagnosis. In practice, confirm that the protocol explicitly includes subtraction, SPECT/CT, and chest coverage, and review the field of view and image quality with nuclear medicine before surgery.