Pre-operative Tc-99m-sestamibi scanning and intra-operative nuclear mapping: are they accurate in localizing parathyroid adenomas?

PURPOSE: Presentation of the results of Tc-99m-sestamibi imaging in the pre-operative localization of parathyroid adenomas and the intra-operative localization of those lesions using a gamma detector (prospective study).

PATIENTS & METHODS: Eighteen consecutive patients aged 27-75 years with primary hyperparathyroidism (PHPT) underwent Tc-99m-sestamibi scanning 1-2 hours before the operation and the presence of a single adenoma was recognized. All our patients underwent bilateral neck exploration based on pre-operative scanning and intra-operative gamma detector guidance and the adenoma was detected in the positions shown by both methods.

RESULTS: In 16 patients we found a single adenoma localized in the same position shown by pre-operative scanning, while the intra-operative method accurately revealed all abnormal glands. In one of the two patients where an inaccurate pre-operative localization technique had been carried out, we performed thyroid lobectomy (the adenoma proved to be intrathyroidal), while the other one had an adenoma which was not close to the site indicated by the pre-operative scintigraphy. Serum calcium reverted to normal within a few days postoperatively.

CONCLUSION: Patients with true-positive scans for single parathyroid adenoma could be eligible for minimally invasive operations since the abnormal gland is easily identified by the above-mentioned methods.