Metabolic tumor burden on postsurgical PET/CT predicts survival of patients with gastric cancer

Abstract

Background: The prognostic value of postoperative 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) to patients with gastric cancer remains unclear. This study aims to investigate the prognostic value of whole body (WB) metabolic tumor burden (MTB WB ) on postsurgical 18 F-FDG PET/CT to patients with gastric cancer. Methods: A total of 376 patients with surgeries-confirmed gastric cancer were enrolled. Clinicopathologic information, overall survival (OS) and MTB WB parameters on postsurgical PET/CT, in terms of WB maximum standardized uptake value (SUV WBmax ), WB metabolic tumor volume (MTV WB ), and WB total lesion glycolysis (TLG WB ) were collected. In-between differences of patient clinicopathologic characteristics, OS and MTB WB measurements were compared using chi-square test, Fisher's exact test, Student's t test or the Kaplan-Meier survival analysis. The optimal cutoffs of MTB WB measurements were calculated through the receiver operating characteristic (ROC) curve analysis. Univariable and multivariable Cox proportional hazard regression were performed to test the predictive value of the clinicopathologic factors and MTB WB measurements to patient survival. Results: The PET-positive patients had significantly decreased OS based on either Kaplan-Meier survival analysis (P < 0.001) or univariable Cox regression (hazard ratio [HR] = 2.850, P < 0.001). In patients with PET-positive tumors, the associations between OS and SUV WBmax , MTV WB and TLG WB were significant, both in univariable analysis (P < 0.001, P < 0.001 and P = 0.001, respectively) and in multivariable analysis (P = 0.002, P < 0.001 and P = 0.005, respectively). Patient OS among groups dichotomized by cutoffs of SUV WBmax > 8.6, MTV WB > 91.5 cm 3 , and TLG WB > 477.6 cm 3 were significantly different (P = 0.001, P < 0.001 and P = 0.001, respectively). Conclusions: MTB WB , in terms of SUV WBmax , MTV WB and TLG WB , on postsurgical 18 F-FDG PET/CT provides prognostic value to patients with gastric cancer after curative resection.