Long‐term survival and value of18f‐fdg pet/ct in patients with gastroenteropancreatic neuroendocrine tumors treated with second peptide receptor radionuclide therapy course with177 lu‐dotatate

Abstract

Peptide receptor radionuclide therapy (PRRT) has been recognized as a promising therapy against neuroendocrine tumors (NETs). The use of18F‐fluorodeoxyglucose (18F‐FDG) positron emission tomography (PET) in NETs has been a matter of controversy. The purpose of this study was to evaluate the long‐term survival and efficacy of a second PRRT course with177Lu‐DOTATE in patients with advanced gastroenteropancreatic (GEP) NETs. Furthermore, the value of18F‐FDG PET/CT in these patients was evaluated. 40 patients with GEP NETs who underwent two PRRT courses with177 Lu‐DOTATATE and combined examinations with68Ga‐DOTA‐TOC and18F‐FDG PET/CT were evaluated. After the second PRRT course, two patients (5.0%) were in partial remission, 21 patients (52.5%) in stable disease and 17 patients (42.5%) had progressive disease. The median overall survival was 122.10 months. After the second PRRT course, the median overall survival was significantly higher (p = 0.033) in the18 F‐FDG‐negative group compared to the18F‐ FDG‐positive group (145.50 versus 95.06 months, respectively). The median time to progression was 19.37 months. In conclusion, a second PRRT course with177Lu‐DOTATE is an effective treatment approach for GEP NET patients with disease progression. A change in18F‐FDG status after PRRT may predict the disease course and survival. Patients who are18F‐FDG‐negative have a significantly longer overall survival than those who are18F‐FDG‐positive.