STMO-11 Supratotal resection of Glioblastoma with Methionine PET

Objective: To assess the resection of both of contrast-enhanced (CE) and methionine-uptake (MU) and the oncological outcome in newly diagnosed glioblastoma. Methods: This retrospective study included a glioblastoma cohort from Chiba University who met the two criteria, i) total resection of CE tumor, ii) preoperative evaluation with methionine positron emission tomography (Met-PET). Data regarding the pattern of recurrence and overall survival were collected. Results: Among 247 cases with glioblastoma, total resection of CE was achieved in 112. Preoperative Met-PET was performed in 30 out of 112. The median age at operation, a period of follow-up, and the preoperative tumor volume in 30 patients were 56 year-old, 17.9 months, and 18.8 cc respectively. The promoter region of the O6-methylguanine-DNA methyltransferase was methylated in 37%. Radiological comparison revealed that Met uptake was detected beyond the CE area in 13 out of 30, and the Met uptake was also resected with awake mapping technique in 7 patients (supratotal resection group; STR). The median progression-free survival (PFS) in STR was 23 months, and all the patterns of recurrence were distant recurrence. In contrast, the PFS in total resection group (TRG) was 9 months (p=0.09, Wilcoxon). Furthermore, 14 out of 17 recurrence were local in TRG subgroup. While the median OS in TRG was 18 months, it has not reached in STR (p=0.04, Wilcoxon). Conclusions: The resection of both of CE and MU was associated with better PFS and OS. This finding must be validated in a larger cohort with a multicenter study.