Speaker
Description
Accurate dosimetry in radiobiological experiments using proton beams requires high resolution, energy-dependent characterization of the Bragg peak, which is essential for understanding variations in Linear Energy Transfer (LET) and the corresponding radiobiological effects along the proton track. Proton beam dosimetry is typically performed using parallel-plate ionization chambers with small sensitive volumes to ensure adequate spatial resolution in regions of steep dose gradients. Monte Carlo simulations are often combined with experimental measurements to enable reconstruction of three-dimensional dose distributions, particularly in specialized setups for in vitro cell irradiation studies.
In this work, proton dosimetry of the MC-35 Scanditronix AB beam at the Oslo Cyclotron Laboratory (OCL), Norway, is presented in support of radiobiological applications. Measurements were conducted using a calibrated Advanced Markus chamber at multiple distances from the beam exit in order to experimentally resolve the Bragg peak profile of the OCL proton beam. Furthermore, Monte Carlo simulations were carried out using the MCNP 6.2 transport code to characterize beam quality parameters and to derive irradiation geometry correction factors necessary for the determination of absorbed dose to water, as well as dose deposition within cellular mono-layers in irradiated culture plates. Independent determination of the absolute proton fluence was achieved using activation foil measurements. The absorbed dose values determined from activation analysis were found to be in good agreement with those obtained via ionization chamber dosimetry, within experimental uncertainties.
The results of this study contribute to the development of a novel, multidisciplinary therapeutic technique that integrates proton therapy with proton-induced sensitizer activation, with the objective of enhancing the selective destruction of Glioblastoma Multiforme cells under controlled proton irradiation conditions.
* This work has received funding from the European Innovation Council (EIC) under grant agreement No. 101130209. The EIC receives support from the European Union’s Horizon Europe research and innovation programme.