THE USE OF TL-201 AND TC-99M SUBTRACTION SCINTIGRAPHY FOR THE LOCALIZATION OF PARATHYROID ADENOMAS

Parathyroid adenomas account for approximately 85% of cases of primary hyperparathyroidism. Several preoperative localisation techniques exi st to aid the surgeon during neck exploration, with varying degrees of success. We report on the results of a modification of the establishe d technique of thallium and technetium subtraction scintigraphy. The o perative findings of 60 patients undergoing neck exploration for parat hyroid adenoma were correlated with preoperative thallium and techneti um subtraction scintigraphy scans. The radio-isotopes were administere d in the reverse order to conventional administration, resulting in en hanced imaging. The adenomatous glands were correctly localised in all cases. The 100% sensitivity of this modified scanning technique suppo rts a strategy of unilateral scan-directed neck exploration.