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

Abstract

Background. To identify parameters based on dual-imaging 18F-AlF-NOTA-octreotide (18F-OC) and 18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) for predicting the prognosis of neuroendocrine neoplasms (NENs). Materials and Methods. Sixty-six patients (age: $\text{mean}\pm \text{standard}\text{deviation}$ (SD): $51.8\pm 11.8$ years) who underwent both 18F-OC and 18F-FDG PET/CT imaging were enrolled in our retrospective study. The following PET parameters were measured: the maximum standardized uptake value (SUVmax) and the volumetric parameters—18F-OC SSR-derived tumor volume (TV) and somatostatin receptor expression (SRE, TV multiplied by the mean standardized uptake value (SUVmean)) and the 18F-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 18F-FDG and 18F-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.