The role of 18F-FDG PET in patients with variable grades of neuroendocrine tumors (NETs) prior to peptide receptor radionuclide therapy (PRRT) has not been adequately elucidated. We aimed to evaluate the impact of 18F-FDG PET status on disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) in neuroendocrine tumor (NET) patients receiving PRRT. We searched the MEDLINE, Embase, Cochrane Library, and Web of Science databases up to July 2020 and used the Newcastle-Ottawa scale (NOS) criteria to assess quality/risk of bias. A total of 5091 articles were screened. In 12 studies, 1492 unique patients with NETs of different origins were included. The DCR for patients with negative 18F-FDG PET status prior to PRRT initiation was 91.9%, compared to 74.2% in patients with positive 18F-FDG PET status (random effects odds ratio (OR): 4.85; 95% CI: 2.27-10.36). Adjusted analysis of pooled hazard ratios (HRs) confirmed longer PFS and OS in NET patients receiving PRRT with negative 18F-FDG PET (random effects HR:2.45; 95%CIs: 1.48-4.04 and HR:2.25; 95% CIs:1.55-3.28, respectively). In conclusion, 18F-FDG PET imaging prior to PRRT administration appears to be a useful tool in NET patients to predict tumor response and survival outcomes and a negative FDG uptake of the tumor is associated with prolonged PFS and OS.
Keywords: 18F-FDG PET; PRRT; neuroendocrine neoplasm.