Intraoperative PTH May Not Be Necessary in the Management of Primary Hyperparathyroidism Even with Only One Positive or Only Indeterminate Preoperative Localization Studies

Background: Intraoperative PTH (IOPTH) monitoring has been widely used to confirm the removal of the culprit lesion during operation. However, the true benefit of IOPTH in patients with preoperatively well-localized single adenoma has been questioned. The aim of this study was to examine how or if IOPTH changes the surgical management and outcomes in patients with only one positive or only indeterminate localization studies. Methods: This is a retrospective review of data from a parathyroid surgery database and patient records from July 2004 to June 2014, including patients with primary hyperparathyroidism with a planned MIP by two experienced endocrine surgeons after ≥1 positive/indeterminate preoperative localization study by ultrasound and/or sestamibi. Results: A total of 482 patients with positive (342: 259 only 1, 83 with ≥2) or indeterminate (140: 105 only 1, 35 with ≥2) preoperative imaging studies were included. IOPTH changed the management in only 16 (3%) patients, with an additional lesion found in 12 of them. Surgical cure was achieved in 471 (98%) of patients (98% in the positive vs. 97% in the indeterminate group, p 0.58). With or without IOPTH, the cure rate would not have been significantly different in patients with only 1 positive preoperative imaging (96 vs. 98%, p 0.12). Similar results were seen in those with ≥2 indeterminate (100% cure rate with or without IOPTH). Conclusion: Our study suggests that MIP may be safely and successfully performed without IOPTH for patients with ≥1 positive or ≥2 indeterminate preoperative imaging studies. This study is retrospective within inherent biases, and future prospective study is warranted.