Detection of parathyroid adenomas in primary hyperparathyroidism. Utility of F‑18 Fluorocholine PET-CT using enhanced CT and ROLL surgery guided by ultrasound

260 Introduction: Parathyroidectomy for persistent/recurrent primary hyperparathyroidism is associated with a higher risk of complications and should be planned only with exactly localisation. We assessed whether 18Fluorocholine (FCH) PET-CT (enhanced CT) could identify parathyroid adenoma(s) in patients with persistent/recurrent primary hyperparathyroidism and negative conventional scans. Materials and Methods: We included 50 patients (16 men and 34 women) with primary hyperparathyroidism and failed pre-surgical localisation of adenoma after conventional protocol (sestamibi SPECT-CT, ultrasound, CT and MRI). Cervical PET-CT scan was performed 10-15 minutes after injection of 18F-Fluoromethylcholine (3 MBq/kg) using intravenous contrast. Not dynamic early images were acquired. Radioguided surgery (ROLL guided by ultrasound) based on information from FCH PET-CT were performed in cases with positive findings and confirmed histopathologically Results: FCH PET-CT ( enhanced CT) detected lesions in 44/50 patients (88%). In these patients, radioguided surgery was performed based on FCH information and adenomas were detected in 42/44 cases (95,4%). Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Mean lesion size was 13.1 ± 8.6 mm. The day before surgery an intralesional dose of 99mTc-MAA was injected guided with ultrasound based on FCH PET-CT findings. The site of injection was confirmed by SPECT-CT image. Intraoperative lesions were localized and excised during surgery using a gamma probe. Minimally invasive parathyroidectomies were performed. Adenomas (histologically confirmed) were located in ectopic positions in 8/42 patients and 32/42 (76.2%) in anatomical positions. In 2/42 surgery procedure failed ought to technical reasons. PTH levels after surgery were normal and follow-up (at least 6 months) confirmed the clinical response in 40/42 cases Discussion: 18Fluorocholine PET-CT (enhanced CT) can identify elusive parathyroid adenomas, including those that are ectopic, and is useful in the management of patients with persistent/recurrent primary hyperparathyroidism when conventional protocols are negative. ROLL radioguided surgery with ultrasound based on FCH findings allows minimal surgical procedures avoiding blinded cervical explorations