The Potential Prognostic Value of Dual-Imaging PET Parameters Based on (18)F-FDG and (18)F-OC for Neuroendocrine Neoplasms

BACKGROUND: To identify parameters based on dual-imaging (18)F-AlF-NOTA-octreotide ((18)F-OC) and 18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) for predicting the prognosis of neuroendocrine neoplasms (NENs). MATERIALS AND METHODS: Sixty-six patients (age: mean ± standard deviation (SD): 51.8 ± 11.8 years) who underwent both (18)F-OC and (18)F-FDG PET/CT imaging were enrolled in our retrospective study. The following PET parameters were measured: the maximum standardized uptake value (SUV(max)) and the volumetric parameters—(18)F-OC SSR-derived tumor volume (TV) and somatostatin receptor expression (SRE, TV multiplied by the mean standardized uptake value (SUV(mean))) and the (18)F-FDG-derived multiple tumor volume (MTV) and tumor lesion glycolysis (TLG). The NETPET grade based on dual-imaging PET images was assessed. Progression-free survival (PFS) was set as an endpoint. Univariate and multivariate survival analyses were performed for PET parameters and clinical tumor data. RESULTS: In the univariate survival analyses of clinical information, PFS was significantly associated with age (>45.5 vs ≤45.5, years, P < 0.034) and the presence of bone metastases (P = 0.04). Higher values for the (18)F-FDG and (18)F-OC volumetric parameters and the NETPET grade were adverse factors for PFS according to the dual-imaging PET parameters. In the multivariate survival analysis, the NETPET grade and SRE were predictors of PFS in NEN patients. CONCLUSION: The NETPET grade is a potential noninvasive prognostic biomarker for NENs.