Sestamibi Scanning and Minimally Invasive Radioguided Parathyroidectomy Without Intraoperative Parathyroid Hormone Measurement

Primary hyperparathyroidism is a benign but sometimes devastating disease. There is concern that the incidence of primary hyperparathyroidism is increasing, with its prevalence approaching 1% in elderly women. 1 Causes include single and double adenomas, multiglandular hyperplasia of a primary and secondary nature, and rarely parathyroid carcinoma. The traditional surgical approach designed to cure patients of this disease has involved careful exploration of the central neck with the intent of first identifying all four parathyroid glands before resecting any glands that appear to be enlarged. To facilitate such a dissection, general endotracheal anesthesia has been necessary. Surgical judgment and expertise have been significant factors, and skilled endocrine surgeons have reported cure rates of 97% to 99% using this approach. 2,3 In the past decade, improvements with parathyroid imaging and the development of a miniaturized hand-held gamma probe have allowed new surgical techniques in the management of patients with primary hyperparathyroidism. Dual-phase technetium-99m sestamibi (MIBI) parathyroid scintigraphy has increased the sensitivity for detecting parathyroid adenoma to 91%, with a specificity of 98.8%. 4 This improvement in parathyroid imaging combined with the development of hand-held gamma probes led to the technique of minimally invasive radioguided parathyroidectomy (MIRP). 5 This procedure, predicated on a positive sestamibi parathyroid scan, allows the surgeon to be guided down to the parathyroid adenoma using the hand-held gamma probe, often without the need for general endotracheal anesthesia. Since the initial report, the technique has been further refined and validated in a large series of patients undergoing initial parathyroid surgery, 6 as well as in patients undergoing reoperative parathyroid surgery. 7 Angelos 8 and Goldstein et al. 9 have also reported the successful application of this technique to patients with primary hyperparathyroidism. In addition to operative success, use of the procedure has resulted in decreased operative time, length of hospital stay, and hospital charges. 4,9 These results support the conclusion that the MIRP procedure can now be considered a standard procedure to be offered to patients with primary hyperparathyroidism. Another development in the past decade that has contributed to an additional choice of procedure for patients with primary hyperparathyroidism has been the quick intraoperative parathyroid hormone assay (iPTH). 10 The current assay can yield a serum parathyroid hormone (PTH) determination in less than 15 minutes. Using the iPTH assay in patients who had successful preoperative localization of a parathyroid adenoma based on a positive parathyroid scan, Irvin et al. 11 and Carty et al. 12 have performed unilateral exploration of the neck with high rates of success. Udelsman et al. used the term “minimally invasive parathyroidectomy” (MIP) for a scan-based unilateral cervical exploration under cervical block using the iPTH determination to confirm the cure. 13 Recently Udelsman reported on results of over 250 MIPs, with a 99% cure rate. 14 Flynn et al. 15 combined the MIRP technique with the iPTH assay and reported excellent results in a small series of patients. The purpose of the current study was to evaluate the results of a large series of MIRPs in which iPTH was not routinely used, and to investigate characteristics between patients who had positive scans and thus were candidates for a MIRP versus those with negative scans.