Aim of the study: To evaluate the results of parathyroid scinti scans (sestamibi or tetrofosmin) for detection of hyperplastic parathyroid glands responsible for renal hyperparathyroidism.
Methods: Injection of 15 mCi sestamibi or tetrofosmin and gammacamera acquisition of images focused on neck and mediastinum, 20 minutes and 2 hours thereafter. Injection of 150 mCi Iodine 123, acquisition of images 2 hours afterwards and visual subtraction.
Patients: 51 patients with renal insufficency or renal transplant were referred for surgical treatment of hyperparathyroidism. 52 scintiscans (sestamibi n = 19, tetrofosmin n = 33) were performed before operation (subtotal parathyroidectomy, bilateral thymectomy and parathyroid tissue cryopreservation).
Results: 180 hyperplastic parathyroid glands were resected, 71 of which had been detected by scintiscan. The factors modifying the results were the weight of the resected lesion and reoperation. All hyperplastic glands were detected in only 1 out of 41 scintiscans performed before first hand operations, whereas all missed glands were imaged in 8 out of the 10 explorations performed before reoperation for persistent renal hyperparathyroidism. The radionuclide, the type of hyperparathyroidism, the parathyroid location, patient's age and gender did not influence the results. No false-positive result was observed.
Conclusion: Parathyroid scintiscan should not be routinely performed before the first neck exploration for renal hyperparathyroidism. It is mandatory in those cases needing reoperation for recurrent disease.