Diagnostic Rechallenge with 18F-FCH PET/CT Often Allows Minimally Invasive Parathyroidectomy While Maintaining Exceptional Cure Rates.

Abstract

Minimally invasive parathyroidectomy(MIP) has gained acceptance as thepreferred surgical procedure for management of primary hyperparathyroidism (pHPT). Appropriate selection of patients for a MIP is a crucial step in its utilization. The aim of the study was to evaluate the role of 18F-FCH PET/CT as second-line imaging for accurately directing MIP. This is a retrospective single-center study. Seventy-two patients with biochemical evidence of pHPT and a non-conclusive or negative first-line imaging (ultrasound and dual isotope subtraction scintigraphy) received 18F-FCH PET/CT between January 2018 and February 2020. All imaging studies were performed at our institution. Assessment of therapeutic changes and outcomes was performed. of the 72 patients imaged with 18F-FCH PET/CT, 54 subsequently underwent parathyroidectomy. When considering the ability of 18F-FCH PET/CT alone to predict a uniglandular disease, the sensitivity, specificity, PPV and NPV were 92.7% (95%CI: 80.1-98.5), 46.2% (19.2-74.9), PPV 87.3% (80.5-92) and NPV 61.2% (31.4-84.5), respectively. When we combined the data provided by 18F-FCH PET/CT with the data already collected from 1st line imaging we were able to complete a minimally invasive surgery in 38 of the 41 (92%) patients with a uniglandular disease. Thirteen patients (24%) had a multiglandular disease, all of them except one underwent bilateral neck exploration based on the data collected by all imaging modalities combined. Overall, cure was achieved in 53 (98%) patients. 18F-FCH PET/CT, interpreted along with first-line imaging results in selected patients, can better facilitate utilization of MIS while maintaining exceptional cure rates.