Dosimetric and clinical results with volumetric modulated radiotherapy for glioblastoma multiforme: Our experience

Abstract

Objective. To evaluate the dosimetric and clinical results with volumetric modulated arc therapy (VMAT) for glioblastoma multiforme (GBM) treatment in our institution. Material and methods. Thirty GBM patients that underwent adjuvant VMAT radiotherapy between January 2017 and June 2019, were assessed considering treatment plan performance and survival data. Means of dose-volume histograms (DVHs) for both planning target volume (PTV) and organs at risk (OARs) were used for the quantitative plan evaluation. Results. A median progression free survival (PFS) of 6.3 months (95%CI: 4.1-8.5) and median overall survival (OS) of 15 months (95%CI: 7.9-22.2) months were recorded. PTV scored a V95% of 97.7±2%, a CI of 0.98±0.02 and a HI of 0.08±0.03. V18Gy for the normal brain was 51.1±17.1%. Treatment plans yielded a number of 517±112.7 monitor units per fraction. Conclusion. We document our radiotherapy practice since VMAT implementation with treatment results consistent with international literature.

Keywords

• glioblastoma multiforme
• volumetric modulated arc therapy
• dosimetry
• survival