Thallium-201-technetium-99m subtraction scanning: its value in 50 cases of hyperparathyroidism submitted to surgery.

Parathyroid surgery was performed on 50 patients following thallium-technetium subtraction scanning. Parathyroid adenomata were correctly localized in 34 (83%). Of eight patients with hyperplastic glands, 15 (75%) of these glands were correctly localized. There were seven (17%) false negative scans and one (2%) false positive result. Thallium-technetium subtraction scanning is a valuable technique in the pre-operative assessment of patients with clinical evidence of hyperparathyroidism.