RESUMO
BACKGROUND: We sought to assess the influence of the clinical introduction of new radiotherapy technologies on glioblastoma patients' outcomes. METHODS: Newly diagnosed glioblastoma patients treated with 60â¯Gy and temozolomide (2005-2014) were analyzed. The patients' GTV and CTV were defined based on MR (nâ¯=â¯521) or FET-PET/MR (nâ¯=â¯190), and were treated using conformal radiotherapy (CRT, nâ¯=â¯159) or image-guided volumetric modulated arc therapy with hippocampal sparing (IG-VMAT, nâ¯=â¯362). Progression-free survival (PFS) was assessed using the McDonald criteria. Associations between clinical data, dosimetry data, treatment technology, for PFS and overall survival (OS) were explored. RESULTS: The PFS (7â¯months) and OS (15â¯months) were unaffected by CRT, IG-VMAT and FET-PET technology. Mean brain dose was correlated with tumor volume, and was lower for IG-VMAT vs. CRT (pâ¯<â¯0.001). Larger mean brain dose was associated with inferior PFS (univariate/multivariate Cox models, pâ¯<â¯0.001) and OS (univariate, pâ¯<â¯0.001). Multivariate Cox models revealed association of larger mean brainstem dose (pâ¯<â¯0.001), BTV (pâ¯=â¯0.045), steroid use at baseline (pâ¯=â¯0.003), age (pâ¯=â¯0.019) and MGMT status (pâ¯=â¯0.022) with lower OS. CONCLUSIONS: Introduction of hippocampal-sparing IG-VMAT technology appeared to be safe, and may have reduced toxicity and cognitive impairment. Larger mean brain dose was strongly associated with inferior PFS and OS.