The Complementary Roles of 18F-Fluorocholine and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in an Evaluation of A Patient With Parathyroid Carcinoma: A Case Report.

18Fluorine-fluorocholine (18F-FCH) is a radiopharmaceutical used in primary hyperparathyroidism. The data about its utility in malignancies other than prostate and hepatocellular carcinoma is limited. We present the case of a patient who was referred for 18F-FCH positron emission tomography/computed tomography (PET/CT) due to the persistently elevated parathormone and calcium levels following total thyroidectomy with left lower parathyroidectomy for parathyroid carcinoma (PTC). Previously, the patient underwent 18Fluorine-fluorodeoxyglucose (18F-FDG) PET/CT. The latter method detected multiple mediastinal and hilar lymph nodes, as well as nodular lesions in lungs and osteolytic bone lesions with an increased tracer uptake, whereas 18F-FCH PET/CT detected an increased tracer uptake not only in lesions at all of the abovementioned areas, but also in the nodular lesion in the neck corresponding to a local relapse as well, with bone lesions showing higher avidity for 18F-FDG than for 18F-FCH. The case we present shows that 18F-FCH PET/CT has an additive value to 18F-FDG PET/CT in an evaluation of patients with PTC.