Inter-subject cerebrovascular variability: a source of uncertainty for dose calculation to circulating blood cells for glioblastoma patients treated with modern radiotherapy techniques.

To assess how inter-subject variations in brain vasculature among glioblastoma (GBM) patients affects the calculated dose received by circulating blood cells (CBC) during radiotherapy and its subsequent impact on CBC depletion.Ten GBM patients treated with either intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) were selected. For each patient, 23 cerebrovascular models were developed based on 23 healthy subject MR-angiography data to simulate intra- and inter-subject blood vessel diversity.