Parathyroid adenomas: accurate detection and localization with Tc-99m sestamibi SPECT

To evaluate the ability to detect and localize parathyroid adenomas with technetium-99m sestamibi single photon emission computed tomography (SPECT).

Forty-seven adult patients underwent Tc-99m sestamibi SPECT. Early (15-30 minutes after injection) and delayed (2-4 hours after injection) images were acquired. Thirty-three patients were examined for initial parathyroid surgery; the remaining 14, for repeat surgery because of persistent or recurrent hyperparathyroidism. SPECT reprojection images viewed in a rotating cine-display mode were read independently by two nuclear medicine physicians who were blinded to the results of other localization studies. Thirty-seven patients underwent subsequent neck exploration. SPECT findings were compared with surgical and histopathologic findings.

In the 37 patients who underwent surgery, parathyroid adenomas were confirmed in 34 (92%) and hyperplasia in three (8%). In 31 patients, adenomas were correctly detected and localized with early SPECT images (sensitivity, 91%). In contrast, the sensitivity of delayed SPECT images was 74% (25 of 34 patients) for detection and 32% (11 of 34 patients) for localization. Early SPECT images were significantly better for localization (P < .001) and detection (P = .03).

For Tc-99m sestamibi parathyroid imaging, early SPECT images were the most accurate in the detection and localization of parathyroid adenomas.