Early, postinjection MIBI-SPECT as the only preoperative localizing study for minimally invasive parathyroidectomy

Early, postinjection technetium Tc 99m sestamibi scintigraphy-single-photon emission computed tomography (MIBI-SPECT) can be used as the only localizing study for focused parathyroidectomy in patients with primary hyperparathyroidism.

During a 26-month period, 82 consecutive patients with primary hyperparathyroidism underwent a standard planar scan using a double-tracer subtraction technique for localization. On the morning of surgery, each patient received radiolabeled technetium Tc 99m sestamibi for intraoperative detection and validation. We performed an early, postinjection SPECT study for comparison with the planar study.

The SPECT study revealed a sensitivity of 96% vs 78% for the planar study. The SPECT study was helpful in locating adenomas in 10 patients with multinodular goiter disease, of whom 3 patients had ectopic adenomas and 2 patients had 2 adenomas each. A significant correlation was noted between uptake ratio and preoperative parathyroid hormone levels (r = 0.41; P =.04). No recurrent or persistent hyperparathyroidism was reported during a follow-up period of at least 6 months.

Our results encourage the use of preoperative SPECT as the only localizing study on the morning of the operation, both to select patients for minimally invasive radioguided surgery and to provide accurate 3-dimensional information on deeply seated or ectopic adenomas. This approach lowers the costs of preoperative localization and intraoperative validation to a single study. The intraoperative gamma probe technique enables the surgeon to focus the search, provides instant feedback regarding the progress of the operation, reduces surgical trauma and complications, and yields better cosmetic results.