Intraoperative parathyroid hormone assay: a necessary tool for multiglandular disease

The aims were to: (1) evaluate whether failure of intraoperative parathyroid hormone (ioPTH) to decrease by the Miami criterion is a more specific indicator of multiglandular disease (MGD) than sestamibi scan and (2) determine an adequate cutoff value for decrease in ioPTH in MGD.

Case series with chart review.

Louisiana State University Health Sciences Center- Shreveport.

Review of subjects undergoing parathyroidectomy using ioPTH and sestamibi for suspected parathyroid adenoma between 2005 and 2009. Patients with MGD were identified by pathology and operative reports.

Eighty-three subjects were identified (68 single adenomas, 11 double adenomas, and 4 multiple-gland hyperplasias). Sestamibi predicted MGD in only 4 of 15 cases (27%). Five of the 11 double adenomas (DAs) were identified during initial surgery; the rest required reoperation for cure. ioPTH was useful in predicting MGD in 7 of 10 cases (70%) when a postexcisional value was drawn after removal of the first enlarged gland. Using the Miami criterion of 50% decrease in ioPTH over 15 minutes would have resulted in 1 unnecessary neck exploration and 3 missed DAs. Requiring both a 50% decrease in ioPTH over 15 minutes and normalization of the postexcisional value would have missed only 1 DA and resulted in a single unnecessary neck exploration.

Sestamibi alone fails to identify MGD 73% of the time, but the success rate increases significantly when combined with ioPTH. The “50% and normal” criterion worked best to increase the success rate in our study population, but larger trials are needed to confirm the utility of this criterion.