The role of cytoreductive surgery in multifocal/multicentric glioblastomas

Abstract

Purpose: Multifocal/multicentric glioblastomas (mGBM) account for up to 20% of all newly diagnosed glioblastomas. The present study investigates the impact of cytoreductive surgery on survival and functional outcomes in patients with mGBM.

Methods: We retrospectively reviewed clinical and imaging data of 71 patients with newly diagnosed primary (IDH1 wildtype) mGBM who underwent operative treatment in 2015-2020 at the authors' institution. Multicentric/multifocal growth was defined by the presence of ≥ 2 contrast enhancing lesions ≥ 1 cm apart from each other.

Results: 36 (50.7%) patients had a resection and 35 (49.3%) a biopsy procedure. MGMT status, age, preoperative KPI and NANO scores as well as the postoperative KPI and NANO scores did not differ significantly between resected and biopsied cases. Median overall survival was 6.4 months and varied significantly with the extent of resection (complete resection of contrast enhancing tumor: 13.6, STR: 6.4, biopsy: 3.4 months; P = 0.043). 21 (58.3%) of resected vs. only 12 (34.3%) of biopsied cases had radiochemotherapy (p = 0.022). Multivariate analysis revealed chemo- and radiotherapy and also (albeit with smaller hazard ratios) extent of resection (resection vs. biopsy) and multicentric growth as independent predictors of patient survival. Involvement of eleoquent brain regions, as well as neurodeficit rates and functional outcomes did not vary significantly between the biopsy and the resection cohorts.

Conclusion: Resective surgery in mGBM is associated with better survival. This benefit seems to relate prominently to an increased number of patients being able to tolerate effective adjuvant therapies after tumor resections. In addition, cytoreductive surgery may have a survival impact per se.

Keywords: Biopsy; Glioblastoma; Growth patterns; Multicentric; Multifocal; Resection.

Fig. 1

Radiological characteristics of multicentric and multifocal growth patterns. a T1 with contrast and FLAIR weighted MR scans showing two contrast enhancing lesions separated by > 1 cm without a T2/FLAIR bridge—multicentric growth pattern. b T1 and FLAIR weighted images with two contrast enhancing lesions separated by > 1 cm connected by a FLAIR hyperintense signal—multifocal growth pattern. c T1 and FLAIR weighted scans depicting three contrast enhancing foci (and possibly a fourth FLAIR hyperintense lesion in the left thalamus). There is a FLAIR hyperintense signal connecting the frontal foci, but no such bridge between the left temporodorsal tumor manifestation and the other lesions—simultaneous multicentric and multifocal growth pattern. d T1 weighted scan with a smaller contrast enhancing lesion located within 1 cm of the main lesion—unifocal growth pattern with satellite lesion. e T1 weighted image showing two contrast enhancing lesions of similar size within 1 cm of one another—unifocal growth pattern

Fig. 2

Prognostic impact of the extent of resection on overall survival (Kaplan-Meier analysis), STR subtotal resection, Complete res. – postop. contrast enhancing tumor volume < 0.1 ml