The standardized uptake value of 18-fluorodeoxyglucose positron emission tomography after chemoradiation and clinical outcome in patients with localized gastroesophageal carcinoma

Background: Empirical trimodality (TM) or bimodality (BM) approaches lead to unpredictable outcomes in patients with localized gastroesophageal carcinoma (LGC). We hypothesized that the standardized uptake value (SUV) of positron emission tomography (PET) after chemoradiation would define the clinical outcome in patients. Methods: We analyzed272 (TM = 155 and BM = 117) LGC patients after chemoradiation PET and studied its association with overall survival (OS) and disease-free survival (DFS). The log-rank test, multivariate Cox proportional hazards model, and Kaplan-Meier survival plots were used to analyze the dichotomized data (using the median as a cutoff). Results: The median survival of TM patients was 49 months (95% CI: 36 to not reached) and that of BM patients was 20 months (95% CI: 15-34; p < 0.0001); however, if the postchemoradiation SUV was <4.6 (4.6 = median SUV), the OS of TM and BM patients was not significantly different (p = 0.22). In the multivariate Cox model, postchemoradiation SUV (p = 0.02), baseline stage (p = 0.03), histology grade (p = 0.01), and having surgery (p = 0.004) were independent prognosticators for OS and DFS. Conclusions: These data document that the low postchemoradiation SUV in both TM and BM patients defines clinical aggression and has a similar clinical outcome. Systematic validation of PET changes, in this setting, can facilitate individualization of therapy of LGC patients.