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Updated: Jun 5, 2025
Irradiator Commissioning and Dosimetry for Assessment of LQ α and β Parameters, Radiation Dosing Schema, and in vivo Dose Deposition
Published on: March 11, 2021
Comparative study of a microdosimetric biological weighting function for RBE10modeling in particle therapy with a
Vladimir A Pan1, Alessio Parisi2,3, David Bolst1
1Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia.
Abstract:
Objective:the recently developed V79-RBE10biological weighting function (BWF) model is a simple and robust tool for a fast relative biological effectiveness (RBE) assessment for comparing different exposure conditions in particle therapy. In this study, the RBE10derived by this model (through the particle and heavy ion transport code system (PHITS) simulatedd(y)spectra) is compared with values of RBE10using experimentally derivedd(y)spectra from a silicon-on-insulator (SOI) microdosimeter.Approach:experimentally measuredd(y)spectra are used to calculate an RBE10value utilizing the V79-RBE10BWF model as well as the modified microdosimetric kinetic model (MKM) to produce an RBE10-vs-ytrend for a wide range of ions. In addition, a beamline specific PHITS simulation was conducted which replicated the exact experimental conditions that were used with the SOI microdosimeter at the heavy ion medical accelerator in Chiba biological beamline with12C ions.Main Results:the RBE10-vs-ytrend for1H,4He,7Li,12C,14N,16O,20Ne,28Si,56Fe, and124Xe ions is examined with good agreement found between the SOI microdosimeter derived RBE10values with the V79-RBE10BWF model and MKM, as well as the PHITS simulations for1H,4He,7Li,12C,16O, and56Fe ions while some discrepancies were seen for14N,20Ne, and28Si ions. Deviations have been attributed to the difference in the derivation of thed(y) spectra based on the different methods utilized. Good agreement was found betweenyvalues and an over estimation was observed for RBE10values for the beamline specific simulation of the12Cion beam.Significance:overall, this study shows that the SOI microdosimeter is a valuable tool that can be utilized for quick and accurate experimental derivation of thed(y) spectra, which can then be convoluted with the weighting function of the V79-RBE10BWF model to derive RBE10. The SOI microdosimeter is able to derive experimental values ofyand RBE10for various ions in any irradiation condition utilizing other radiobiological models.
