SURG-12THE SUB-PIAL RESECTION TECHNIQUE FOR SUPRA-MAXIMAL RESECTION OF GLIOBLASTOMAS

Abstract

BACKGROUND: Despite advances in chemotherapy and surgical approaches, the median overall survival (OS) for patients with GBM remains poor. A “supra-maximal” resection, using the sub-pial technique for low-grade gliomas aims to remove immediately proximate abnormal tissue beyond the zone of enhancement on MRI. The purpose of this study is to evaluate the feasibility and survival benefit of this technique in patients with GBM. METHODS: We retrospectively evaluated 86 consecutive patients operated on for primary GBM using the sub-pial technique with or without BCNU wafer implantation and adjuvant therapy. Presenting clinical, radiological and outcome data were collected. Multivariate Cox proportional hazards regression was used to analyze variables associated with survival. Survival was compared using Kaplan-Meier plots to stratify the impact of extent of resection (EOR) and BCNU. RESULTS: Patient age (mean) was 56 years with a 93.8% median EOR. Median OS for the group was 18.1 months and 54, 16.5 and 13.2 for GTR, NTR and STR respectively. 34.2 and 13.2 months for patients with >95% and <95% EOR. Patients undergoing NTR (p = 0.05) or GTR (p < 0.01) experienced longer survival time than patients undergoing STR as well as ≥ 95% EOR (p < 0.01) when compared to <95% EOR. BCNU had no additional advantage on survival in this cohort. CONCLUSIONS: This is the first study to evaluate the use of the sub-pial technique for resection of GBM. This technique is associated with an OS benefit not previously seen in other similar series in which resection of the enhancement portion is performed. The effect of supra-maximal resection on survival exceeded the effects of age, KPS and tumor volume at presentation. A prospective study is needed to evaluate the impact of the sub-pial technique in both quality of life and survival as compared to a traditional resection of the enhancing portion of the tumor.