Comparative study of a microdosimetric biological weighting function for RBEmodeling in particle therapy with a solid state SOI microdosimeter.

The recently developed V79-RBEbiological 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 RBEderived by this model (through the Particle and Heavy Ion Transport code System (PHITS) simulated d(y) spectra) is compared with values of RBEusing experimentally derived d(y) spectra from a silicon-on-insulator (SOI) microdosimeter. Approach: Experimentally measured d(y) spectra are used to calculate an RBEvalue utilizing the V79-RBEBWF model as well as the modified microdosimetric kinetic model (MKM) to produce an RBE-vs-ytrend for a wide range of ions.

Validation of Light-Ion Quantum Molecular Dynamics (LIQMD) model for hadron therapy.

Purpose: This study aims to validate the Light-Ion Quantum Molecular Dynamics (LIQMD) model, an advanced version of the QMD model for more accurate simulations in hadron therapy, incorporated into Geant4 (release 11.2).

Methods: Two sets of experiments are employed.

Energy imparted and ionisation yield at the nanometre scale: results for extended beams.

The metrological problem of interpreting ionisation-based micro- and nanodosimetric measurements in terms of quantities proportional to energy imparted becomes particularly relevant when the sensitive volume (SV) size is in the nanometre range. At these scales, a constant W-value cannot be assumed, and the stochastics of the energy transfer per single collision could play a more important role. This problem was recently analysed by our group by means of track-structure Monte Carlo simulations with the Geant4-DNA code, finding a strong correlation between the energy imparted and ionisation yield also for SV diameters of 1 nm.

A Geant4 shielding design for the first US carbon multi-ion hybrid synchrotron facility.

The Mayo Clinic Florida Integrated Oncology Building will be the home of the first spot-scanning only carbon/proton hybrid therapy system by Hitachi, Ltd. It will provide proton beams up to kinetic energies of 230 MeV and carbon beams up to 430 MeV nfor clinical deployment. To provide adequate radiation protection, the Geant4 (v10.