INTRAOPERATIVE NUCLEAR GUIDANCE IN BENIGN HYPERPARATHYROIDISM AND PARATHYROID CANCER

The success of parathyroid surgery is determined by the identification and removal of all hyperactive parathyroid tissue. Ectopic location o f parathyroid tumours and fibrosis due to previous operations can caus e failure of parathyroidectomy. Parathyroid tumours accumulate and ret ain 2-methoxyisobntylisonitrile (MIBI) labelled with technetium-99m. T his study assesses the value of intra-operative localization of parath yroid rumours using a hand-held gamma detector in patients with hyperp arathyroidism and parathyroid cancer. Twenty patients undergoing their first operations for hyperparathyroidism, 15 patients undergoing reop erations for either persistent or recurrent hyperparathyroidism and tw o patients with parathyroid cancer were studied. Radioactivity in the neck and the mediastinum was recorded by a gamma detector after admini stration of 370 MBq Tc-99m-MIBI. Surgical findings and postoperative s erum levels of calcium were documented. The sensitivity of the gamma d etector in identifying parathyroid rumours was 90.5% in first parathyr oidectomies. 88.9% in reoperations for either persistent or recurrent hyperparathyroidism and 100% in parathyroid cancer. One false-positive result was due to a thyroid nodule. Hypercalcaemia ceased in all but one patient postoperatively. It is concluded that employment of the ga mma detector is to be advocated in first parathyroidectomies when a pa rathyroid tumour cannot be discovered, in reoperations for either pers istent or recurrent hyperparathyroidism and in surgery for parathyroid cancer.