Increased relative biological effectiveness and periventricular radiosensitivity in proton therapy of glioma patients.

Purpose: Currently, there is an intense debate on variations in intra-cerebral radiosensitivity and relative biological effectiveness (RBE) in proton therapy of primary brain tumours. Here, both effects were retrospectively investigated using late radiation-induced brain injuries (RIBI) observed in follow-up after proton therapy of patients with diagnosed glioma.

Methods: In total, 42 WHO grade 2-3 glioma patients out of a consecutive patient cohort having received (adjuvant) proton radio(chemo)therapy between 2014 and 2017 were eligible for analysis.

Impact of range uncertainty on clinical distributions of linear energy transfer and biological effectiveness in proton therapy.

Purpose: Increased radiation response after proton irradiation, such as late radiation-induced toxicity, is determined by high dose and elevated linear energy transfer (LET). Steep dose-averaged LET (LET ) gradients and elevated LET occur at the end of proton range and might be particularly sensitive to uncertainties in range prediction. Therefore, this study quantified LET distributions and the impact of range uncertainty in robust dose-optimized proton treatment plans and assessed the biological effect in normal tissues and tumors of patients.

Material assignment for proton range prediction in Monte Carlo patient simulations using stopping-power datasets.

Unlabelled: Motivation and objective. For each institute, the selection and calibration of the most suitable approach to assign material properties for Monte Carlo (MC) patient simulation in proton therapy is a major challenge. Current conventional approaches based on computed tomography (CT) depend on CT acquisition and reconstruction settings.

A Monte Carlo based radiation response modelling framework to assess variability of clinical RBE in proton therapy.

The clinical implementation of a variable relative biological effectiveness (RBE) in proton therapy is currently controversially discussed. Initial clinical evidence indicates a variable proton RBE, which needs to be verified. In this study, a radiation response modelling framework for assessing clinical RBE variability is established.