Study of relationship between dose, LET and the risk of brain necrosis after proton therapy for skull base tumors

• DOI: 10.1016/j.radonc.2021.08.015
• Publication Date: 2021-08-27T07:10:43Z
• Authors: Magdalena Garbacz; Francesco Giusepp...; Marco Durante; Jan Gajewski; Kamil Kisielewicz; Nils Krah; Renata Kopeć; Paweł Olko; Vincenzo Patera; Ilaria Rinaldi; Marzena Rydygier; Angelo Schiavi; Emanuele Scifoni; Tomasz Skóra; Francesco Tommasino; Antoni Rucinski
• Keywords: Brain Edema

We investigated the relationship between RBE-weighted dose (DRBE) calculated with constant (cRBE) and variable RBE (vRBE), dose-averaged linear energy transfer (LETd) risk of radiographic changes in skull base patients treated protons.Clinical treatment plans 45 were recalculated Monte Carlo tool FRED. Radiographic (i.e. edema and/or necrosis) identified by MRI. Dosimetric parameters for cRBE vRBE computed. Biological margin extension voxel-based analysis employed looking association DRBE(vRBE) LETd brain necrosis.When using vRBE, Dmax was above highest limits 38% patients, while such limit never exceeded assuming cRBE. Similar values observed necrotic regions, temporal lobes. Most necrosis proximity to PTV. The did not show evidence an high values.When at standard dosimetric parameters, higher associated seems be responsible enhanced changes. However, as revealed a analysis, large inter-patient variability hinders identification clear effect LETd.