STMO-3 Mid- to long-term outcome of supratotal resection of IDH1 wild-type glioblastoma based on 11C-methionine PET: a retrospective, single-center study

Abstract Purpose Mid- to long-term outcome in glioblastoma (GBM) patients following supratotal resection (SupTR), involving complete resection both of contrast-enhancing enhanced (CE) tumors and areas of methionine (Met) uptake on 11C-Met positron emission tomography (Met-PET), are not clarified. Methods A retrospective, single-center review was performed in newly diagnosed, IDH1 wild-type GBM patients, comparing SupTR with gross total resection (GTR), in which only CE tumor tissue was completely resected. Only patients who were operated on until November 2019 were included for evaluation of mid- to long-term outcome. Following resection, all patients underwent standard radiotherapy and temozolomide treatment, and were followed for progression-free survival (PFS) and overall survival (OS). Results Among the 30 patients included in this study, 7 underwent SupTR and 23 underwent GTR. Awake craniotomy with cortical and subcortical mapping was more frequently performed in the SupTR group than in the GTR group. During the follow-up period, significantly different patterns of disease progression were observed between groups. Although more than 80% of recurrences were local in the GTR group, all recurrences in the SupTR group were distant. Median PFS in the GTR and SupTR groups was 8.8 months (95% confidence interval [CI], 5.2–14.9) and 27.8 months (95% CI, 6.0-not estimable) respectively (p=0.08 by log-rank test). Median OS was 17.7 months (95% CI, 14.2–35.1) in GTR and not reached (95% CI, 30.5-not estimable) in SupTR, respectively; this difference was statistically significant (p=0.03 by log-rank test). No postoperative neurocognitive impairment was observed in SupTR patients. Conclusion Compared to GTR alone, SupTR strategy with aggressive resection of both CE tumors and Met uptake area in GBM patients under awake craniotomy with functional preservation results in a survival benefit associated with better local control.