To compare the sensitivity and positive predictive value (PPV) of pinhole dual-phase Tc-99m sestamibi vs combined Tc-99m sestamibi and Tc-99m pertechnetate
scintigraphy in patients with hyperparathyroidism where single-photon emission computed tomography (SPECT)/CT is unavailable.
All patients with biochemically proven hyperparathyroidism who underwent both pinhole Tc-99m sestamibi and Tc-99m pertechnetate
scintigraphy between January 2012 and December 2017 with surgery performed within 3 months of imaging were analyzed. Tc-99m sestamibi images alone and combined with Tc-99m pertechnetate
images were interpreted by two nuclear medicine physicians. The sensitivity and PPV of the two imaging approaches were determined based on the surgical findings.
Of the 38 patients included, surgery revealed 33 single parathyroid adenomas (PA), one double adenoma and four parathyroid hyperplasia (PH). On a per-patient basis, the sensitivity and PPV for detection of PA or PH were 76% and 100%, respectively, with Tc-99m sestamibi alone vs 84% and 100% using the combined approach. For PA, the sensitivity and PPV were 82% and 100%, respectively, with Tc-99m sestamibi alone vs. 91% and 100% with the combined approach. PH was identified in only one of four patients with Tc-99m sestamibi alone or in combination. There were no significant differences in sensitivity (P
= 0.08) and PPV (P
> 0.99) between Tc-99m sestamibi alone and Tc-99m sestamibi with Tc-99m pertechnetate
Pinhole dual-phase Tc-99m sestamibi alone has high accuracy in the detection of PA. The routine addition of Tc-99m pertechnetate
to Tc-99m sestamibi does not result in significant improvement in the detection of PA or PH and should be reserved for equivocal cases.