Prognostic Value of Volume-Based Parameters Measured by SSTR PET/CT in Neuroendocrine Tumors: A Systematic Review and Meta-Analysis

Purpose: A meta-analysis was conducted to investigate the value of the volume parameters based on somatostatin receptor (SSTR) PET in predicting the prognosis in neuroendocrine tumors (NETs) patients. Material: PubMed, Embase, Cochrane library, and Web of Knowledge were searched from January 1990 to May 2021 for studies evaluating prognostic value of volume-based parameters of SSTR PET/CT in NETs. The terms used were “volume”, “positron emission tomography”, “neuroendocrine tumors”, and “somatostatin receptor”. Pooled hazard ratio (HR) values were calculated to assess the correlations between volumetric parameters, including total tumor volume (TTV) and tota-lesion somatostatin receptor expression (TL-SSTR), with progression-free survival (PFS) and overall survival (OS). Heterogeneity and subgroup analysis were performed. Funnel plots and Egger’s test were used to assess possible underlying publication bias. Results: Eight eligible studies involving 593 patients were included in the meta-analysis. In TTV, the pooled HRs of its prognostic value of PFS and OS were 2.01 (95% CI, 1.19–3.41; P = 0.009) and 3.54 (95% CI, 1.77–7.09; P = 0.0004), respectively. In TL-SSTR, the pooled HR of the predictive value was 2.44 (95% CI, 1.14–5.24; P = 0.02) for PFS. Conclusion: High TTV and TL-SSTR were associated with a worse prognosis for PFS and OS in NETs patients. The volume-based parameters of SSTR PET are a potential objective prognosis predictor.