Are additional localization studies and referral indicated for patients with primary hyperparathyroidism who have negative sestamibi scan results?

HYPOTHESIS: Additional imaging studies are useful to select patients who are candidates for minimally invasive parathyroidectomy, and referral is not indicated when results from a preoperative sestamibi scan are negative.

DESIGN, SETTING, AND PATIENTS: Prospective analysis of 492 operations for primary hyperparathyroidism from May 2005 to May 2007 at a tertiary care center.

MAIN OUTCOME MEASURES: Accuracy of imaging studies, pathologic findings, and biochemical cure.

RESULTS: Among the patients, 96% were cured. Of the sestamibi scan results, 91% were positive and 82% were true-positive. Ultrasonography results were positive in 51% of patients with negative sestamibi scan results, and 43% were true-positive. Patients with positive sestamibi scan results compared with those with negative sestamibi scan results had a higher rate of single-gland disease (87% vs 63%, respectively) and lower rates of double adenoma (6% vs 22%, respectively) and asymmetric hyperplasia (7% vs 15%, respectively) (P<.001). In patients with positive sestamibi scan results compared with those with negative sestamibi scan results, there was no significant difference in the rate of ectopic parathyroid glands (18% vs 12%, respectively) but there was a significant difference in cure rate (97% vs 89%, respectively) (P=.008).

CONCLUSIONS: Additional imaging with neck ultrasonography is helpful for selecting minimally invasive parathyroidectomy in most patients with primary hyperparathyroidism who have negative sestamibi scan results. Referral for parathyroidectomy may be considered in patients with negative sestamibi scan results because these results are associated with multigland disease and lower cure rates.