¹¹C-choline PET/CT for detection and localization of parathyroid adenomas

OBJECTIVE. The purpose of this study is to determine the effcacy of 11C-choline PET/CT for the detection of parathyroid adenomas by retrospectively reviewing a large patient population. MATERIALS AND METHODS. In this single-institution retrospective study, 7088 11C-choline PET/CT scans performed of 2933 men with prostate cancer from January 2005 through February 2016 were evaluated. Patients with suspected parathyroid adenomas were identifed through a review of the electronic medical record and relevant imaging. Patient demographics, laboratory results, and lesion characteristics were noted. Pathologically proven parathyroid adenomas and lesions in patients with imaging or laboratory fndings consistent with the diagnosis were considered positive. RESULTS. Thirteen men (mean [± SD] age, 72 ± 7 years) with pathologically or laboratory-proven parathyroid adenomas were identifed. All had abnormally elevated serum calcium and parathyroid hormone levels. All adenomas were tracer avid on 11C-choline PET/CT (maximum standardized uptake value, 5.6 ± 3.0), with activity averaging 4.2 times that of the blood pool and 2.1 times that of the adjacent thyroid. One case of an ectopic adenoma was identifed. Of the six pathologically confrmed cases, none displayed high-grade features such as capsular, vascular, or adjacent tissue invasion. Three additional patients with possible parathyroid adenomas at 11C-choline PET/CT were ultimately found to have thyroid lesions on the basis of tissue diagnosis; however, none of these patients had abnormal calcium or parathyroid hormone levels. CONCLUSION. In our patient population, 11C-choline PET/CT identifed parathyroid adenomas with high specifcity. Prospective investigation is warranted to validate this result and delineate the utility of 11C-choline PET/CT relative to other modalities.