Open Low-field Magnetic Resonance Imaging for Target Definition, Dose Calculations and Set-up Verification during Three-dimensional CRT for Glioblastoma Multiforme

GTVs defined on computed tomography were significantly larger than those delineated on MRI. Compared with computed tomography-derived plans, MRI-based dose calculations were accurate. The precision of set-up verifications based on computed tomography- and MRI-derived DRRs seemed similar. The use of MRI only for the planning of GBM should be further assessed.