Experienced Radio-Guided Surgery Teams Can Successfully Perform Minimally Invasive Radio-Guided Parathyroidectomy without Intraoperative Parathyroid Hormone Assays

Abstract

Minimally invasive parathyroidectomy is an accepted treatment option for primary hyperparathyroidism. The need for intraoperative parathyroid hormone assays (iPTH) to confirm adenoma removal remains controversial. We studied minimally invasive radio-guided parathyroidectomy (MIRP) performed using preoperative sestamibi localization studies, intraoperative gamma detection probe, and the selective use of frozen section pathology without the use of iPTH. This is a single institution review of patients with primary hyperparathyroidism treated with MIRP by surgeons experienced in radio-guided surgery between October 1, 1998 and July 15, 2005. Information was obtained by reviewing computer medical records as well as contacting primary care physicians. Factors evaluated included laboratory values, pathology results, and evidence of recurrence. One hundred forty patients were included with a median preoperative calcium level of 11.3 mg/dL (range, 9.6-17) and a PTH level of 147 pg/mL (range, 19-5042). The median postoperative calcium level was 9.3 mg/dL. All patients were initially eucalcemic postoperatively except for one who had normal parathyroid levels. However, five (4%) patients required re-exploration for various reasons. Of the failures, one was secondary to the development of secondary hyperparathyroidism, and therefore would not have benefited from iPTH, one had thyroid tissue removed at the first operation, and three developed evidence of a second adenoma. One of these three patients had a drop in PTH level from 1558 pg/mL preoperatively to 64 pg/mL on postoperative Day 1, indicating that iPTH would not have prevented this failure. Thus, only three (2.1%) patients could have potentially benefited from the use of iPTH. MIRP was successful in 96 per cent of patients using a combination of preoperative sestamibi scans, intraoperative localization with a gamma probe, and the selective use of frozen pathology. This correlates with reported success rates of 95 per cent to 100 per cent using iPTH. We conclude that minimally invasive parathyroidectomy can be successfully performed without using iPTH assays.