Post-surgical therapeutic approaches to glioblastoma patients submitted to biopsy (BA) or "partial" resection (PR): the possibilities to treat also them without renunciations. Study from the Brescia Neuro-Oncology Group

The extent of surgery predicts overall survival (OS) in patients treated for glioblastoma (GBM). The therapeutic approach after partial resection (PR) or biopsy alone (BA) is not clearly defined. This retrospective analysis was therefore planned to analyse clinical features, treatment and survival of patients undergoing PR or BA. We analysed the clinical/therapeutic features and the outcome of 232 patients submitted to BA/PR and treated with radiotherapy (RT) with/without chemotherapy. Two subgroups (pre- and post-Temozolomide-era) were identified. The BA/PR ratio did not change with the accrual periods. In the TMZ-era, 50 % of the patients had chemotherapy; "small" volume, hypo-fractionated and "low" dose RT (<54 Gy) were delivered to 93, 38 and 44 % of the patients; corresponding values for the previous period were 4, 28, 11 and 2 % (P < 0.001). Better two-year OS was evident in the TMZ-era (18 vs 7 %); PR and chemotherapy affected OS in patients treated with hypo-fractionated, low doses RT (P = 0.02, 0.04). Limited volume, more often MRI-based, and "short" RT treatments were given mostly to unfavourably selected patients, without compromising the results of the whole group. This strategy, combined with an increased use of chemotherapy, resulted in reduced treatment burden, in an improved 2-year OS rate and prospectively in better quality of life, even in this prognostically worse subset of glioma patients.