Localization of parathyroid tumours in the minimally invasive era: which technique should be chosen? Population-based analysis of 253 patients undergoing parathyroidectomy and factors affecting parathyroid gland detection.

A series of 253 consecutive patients with proved primary hyperparathyroidism due to parathyroid tumours was reviewed. There were 68 (26.9%) men and 185 (73.1%) women, with a median age of 57 years (range 13-82 years). All patients, prior to successful parathyroidectomy, underwent one or more preoperative localization procedures such as: neck ultrasonography (US) in 191 (75.5%), (201)Tl/(99m)Tc-pertechnetate subtraction scintigraphy (TPS) in 144 (56.9%), CT scan in 92 (36.4%), (99m)Tc-sestamibi/(99m)Tc-pertechnetate subtraction scintigraphy (MPS) in 90 (35.6%), selective venous sampling (SVS) with parathyroid hormone (PTH) assay in 30 (11.9%), and magnetic resonance imaging (MRI) in 6 (2.4%) patients. The results were compared with operative and histological findings that showed 235 (92.9%) solitary parathyroid adenomas, 13 (5.1%) carcinomas and 5 (2.0%) double adenomas. Sensitivity and positive predictive value were 82.9% and 93.8% for US, 83.6% and 91.8% for TPS, 81.3% and 98.7% for CT scan, 85.1% and 96.1% for MPS, 65.4% and 80.9% for SVS, and 80.0% and 80.0% for MRI respectively. No different results (P=NS) were found using US, TPS, MPS or CT scan, whereas SVS and MRI sensitivity was lower (P<0.05). The combination of MPS and US was 94.0% sensitive (P<0.05) but when TPS, CT scan or MRI were also used overall sensitivity did not improve significantly (P=NS). In conclusion, MPS should be used as the starting preoperative localization procedure, while US and MPS together represent the most reliable noninvasive localization tool. If MPS and US are negative or not in agreement, further studies are not cost-effective and the patient should undergo bilateral neck exploration.