Unilateral surgery for primary hyperparathyroidism on the basis of technetium Tc 99m sestamibi and iodine 123 subtraction scanning

Hypothesis: Parathyroid scanning, based on simultaneous recording of technetium Tc 99m sestamibi and iodine 123 images, is able to identify patients with multiple parathyroid gland disease and is a safe imaging technique for unilateral parathyroid surgery. Design: Scintigraphic criteria of eligibility for unilateral surgery were prospectively tested against findings of conventional bilateral surgery. Setting: Patients referred to an endocrine surgeon in a university hospital. Patients: Seventy consecutive patients with primary hyperparathyroidism had dual-isotope scanning before conventional surgery. Forty-one patients had scan findings compatible with unilateral surgery, with a single focus of high intensity seen on the anterior and lateral views. The remaining 29 patients had 1 or more criteria of ineligibility: (1) scan findings pointing to multiple gland disease, (2) no well-identified focus, (3) contralateral thyroid nodule requiring surgical management, or (4) family history of hyperparathyroidism or multiple endocrine disease. Main Outcome Measures: Number of enlarged parathyroid glands at surgical inspection and calcemia follow-up. Results: None of the 41 patients, with a single well-defined focus on the scan image, showed evidence of multiple parathyroid involvement. Each parathyroid adenoma was resected from the precise site predicted by the subtraction scan. Nine patients (13%) had surgical findings of multiple parathyroid gland disease. All 9 were ineligible based on preoperative image findings. Conclusions: Unilateral surgery can be safely offered Co 60% of patients with primary hyperparathyroidism,, on the basis of simultaneous Tc-99m-sestamibi and I-123 scanning. This may reduce the length of the operation, anesthesia requirements, and hospital stay, and the risks of hypoparathyroidism and injury to the recurrent laryngeal nerve.