Resection of positive tissue on methionine-PET is associated with improved survival in glioblastomas

Abstract

Background and purpose: The volume of excised tumor in contrast-enhanced areas evaluated via magnetic resonance imaging is known to have a strong influence on the survival of patients with glioblastoma (GBM). In this study, we investigated the effect of tumor resection on the survival of patients with GBM in the 11C-methionine (MET) accumulation area using MET-positron emission tomography (MET-PET). Methods: A total of 26 patients (median age, 69 years; 15 males) who had undergone tumor resection and MET-PET before and after surgery, after being newly diagnosed with GBM, were included in the study. MET-PET before and after tumor resection were compared. The association between the decrease in the maximum standardized uptake value (SUV) of the tumor divided by the normal cortical mean SUV (%; ΔT/N), the MET extent of resection (MET-EOR) from the % reduction in the MET accumulation area (%), and residual MET accumulation area (in cm3; MET-residual tumor volume [RTV]), as well as the survival time of patients with GBM, were evaluated via univariate analysis. Results: ΔT/N were positively associated with survival (hazard ratio [HR], 0.98 [95% confidence interval (CI), 0.97–0.99], p =.02). MET-RTV revealed a negative association with survival (HR, 1.02 [95% CI, 1.01–1.04], p =.04). Additionally, MET-EOR showed a strong trend with survival (HR, 0.99 [95% CI, 0.97–1.01], p =.06). Conclusions: Surgical resection of MET-accumulated areas in GBM significantly prolongs the survival of patients with GBM. However, a prospective large-scale multicenter study is needed to confirm our findings.