Abstract
PURPOSE: (11)C-Methionine PET/CT is a promising method for detecting parathyroid lesions in patients with primary hyperparathyroidism (PHPT). We aimed to determine the diagnostic ability and correlation of digital (11)C-Methionine PET/CT for parathyroid lesions in patients with PHPT, particularly in cases where standard imaging methods yielded inconclusive results. METHODS: This retrospective analysis was conducted on patients diagnosed with PHPT who underwent digital (11)C-Methionine PET/CT imaging because of ambiguous results on standard imaging work-up ((99m)Tc-MIBI parathyroid scan and/or neck ultrasonography). Quantitative (11)C-Methionine PET/CT parameters, including maximum standardized uptake value (SUVmax), mean SUV (SUVmean), peak SUV (SUVpeak), parathyroid methionine volume (PMV), and whole methionine uptake (WMU: PMV multiplied by SUVmean) were calculated with various thresholds, and their correlations with biochemical and pathologic parameters were investigated. RESULTS: This study included 22 consecutive patients (10 men and 12 women) with a median age of 64.0 years. The lesion detection rate and sensitivity of digital (11)C-Methionine PET/CT were 81.8% (18/22) and 100.0% (18/18), respectively. Quantitative analysis revealed that serum PTH (r = 0.490, P = 0.039) and serum calcium (r = 0.583, P = 0.011) were significantly correlated with PMV50%. CONCLUSION: Digital (11)C-Methionine PET/CT offers good performance in the detection of parathyroid lesions in PHPT patients with inconclusive standard imaging work-up. The volume parameter of PMV50% significantly correlated biochemical parameters and can serve as a complementary diagnostic tool. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13139-024-00878-x.