Octreoscan SPET evaluation in the diagnosis of pancreas neuroendocrine tumors.

The study describes the results of Octreoscan SPET (OCTSPET) qualitative and semi-quantitative evaluation in 38 patients with suspected pancreatic neuroendocrine tumors. SPET studies were acquired at 4 and 24 hours after the injection of 111-220 MBq of 111-In-pentetreotide (Octreoscan). Qualitative and semi-quantitative evaluations were performed. The semi-quantitative approach was based on the time course of Tumor/Non Tumor ratios (TNTinc) from 4 and 24 hours. The OCTSPET results were true positive in 18 of 19 patients (10 gastrinoma, 5 insulinoma, 1 neuroendocrine tumor, 1 glucagonoma and 1 carcinoid) and false negative in one insulinoma. Besides, 20 of 38 patients (52%) had clinical plans modified after OCTSPET; OCTSPET was the only positive diagnostic test in 14 of 19 patients (73%) and guided the surgery decision in 14 of 25 patients (56%). In conclusion, these data indicate that Octreoscan represents an excellent tool for the diagnosis of pancreatic neuroendocrine tumors.