Preoperative technetium Tc 99m sestamibi imaging. Paving the way to minimal-access parathyroid surgery.

OBJECTIVE: To examine the reliability of technetium Tc 99m sestamibi scanning as a new adjunct to the surgical management of hyperparathyroidism.

DESIGN: Preoperative localization of parathyroid adenoma by technetium Tc 99m sestamibi delayed washing-out scanning and high-resolution ultrasound was compared with a historical institutional experience of surgical intervention without preliminary localization studies. A 10-year retrospective review from 1985 to 1995 of patients with surgical hyperparathyroidism was performed.

SETTING: Academic tertiary referral medical center.

PATIENTS: Thirty-three technetium Tc 99m sestamibi scans in patients with primary hyperparathyroidism were correlated with eventual surgical and pathologic findings. The last 10 patients were also studied with 10-MHz linear transducer ultrasound, and the results were compared with those of the radionuclide scan and eventual surgical and pathologic findings. From 1985 to 1995, 142 patients underwent surgical exploration for primary hyperparathyroidism, and 125 records were available for review.

RESULTS: The technetium Tc 99m sestamibi parathyroid scan correctly identified the site and presence of 31 adenomas among 34 confirmed tumors, a sensitivity of 91% and positive predictive value of 97%. The scan detected three anterior mediastinal adenomas that could not be removed through cervical exploration. In each instance median sternotomy was included in the primary surgery and allowed efficient, successful management of these ectopic adenomas. High-resolution ultrasound correctly identified nine of 10 cervical parathyroid adenomas and predicted the volume of each tumor to a statistically significant level.

CONCLUSIONS: Hyperthyroidism has traditionally been treated surgically without preliminary localization studies. We found both technetium Tc 99m sestamibi scanning and high-resolution ultrasound to be highly sensitive at detecting parathyroid adenomas at the 90% level. Furthermore, preoperative localization allowed efficient surgical intervention for our group of patients who had high frequency of mediastinal adenomas that required transmediastinal surgery.