DNA-damage RBE assessment for combined boron and gadolinium neutron capture therapy.

Purpose: Neutron capture therapy (NCT) by 10B and 157Gd agents is a unique irradiation-based method which can be used to treat brain tumors. Current study aims to quantitatively evaluate the relative biological effectiveness (RBE) and dose distributions during the combined BNCT and GdNCT modalities through a hybrid Monte Carlo (MC) simulation approach.

Methods: Snyder head phantom as well as a cubic hypothetical tumor was at first modeled by Geant4 MC Code.

An inter-comparison between radiobiological characteristics of a commercial low-energy IORT system by Geant4-DNA and MCDS Monte Carlo codes.

Introduction: The need for accurate relative biological effectiveness (RBE) estimation for low energy therapeutic X-rays (corresponding to 50 kV nominal energy of a commercial low-energy IORT system (INTRABEAM)) is a crucial issue due to increased radiobiological effects, respect to high energy photons. Modeling of radiation-induced DNA damage through Monte Carlo (MC) simulation approaches can give useful information. Hence, this study aimed to evaluate and compare RBE of low energy therapeutic X-rays using Geant4-DNA toolkit and Monte Carlo damage simulation (MCDS) code.

Impact of gadolinium concentration and cell oxygen levels on radiobiological characteristics of gadolinium neutron capture therapy technique in brain tumor treatment.

Neutron capture therapy (NCT) with various concentrations of gadolinium (Gd) is one of the treatment modalities for glioblastoma (GBM) tumors. Current study aims to evaluate how variations of Gd concentration and cell oxygen levels can affect the relative biological effectiveness (RBE) of gadolinium neutron capture therapy (GdNCT) technique through a hybrid Monte Carlo (MC) simulation approach. At first, Snyder phantom including a spherical tumor was simulated by Geant4 MC code and relevant energy electron spectra to different Gd concentrations including 100, 250, 500, and 1000 ppm were calculated following the neutron irradiation of simulated phantom.

Secondary cancer risk assessments following the proton therapy of lung cancer as the functions of field characteristics and patient age.

Introduction: Radiation-induced secondary cancers relevant to proton therapy are still a main concern among cancer survivors. This study aims to determine the effects of age at exposure and treatment field size on radiation-induced secondary tumors following the proton therapy of lung cancer within out of field organs through the Monte Carlo (MC) simulation approach.

Material And Methods: A full MC model of ICRP-110 male phantom was simulated to calculate the absorbed dose corresponding to secondary radiations within distant organs from the tumor volume.

Impact assessment of breast glandularity on relative biological effectiveness of low energy IORT X-rays through Monte Carlo simulation.

Introduction: Intraoperative radiotherapy (IORT) by low energy X-rays is a single fraction treatment modality for tumor bed irradiation after breast-conserving surgery. It has been shown that the variations of breast tissue composition can affect the absorbed dose in this method. Apart from physical quantities such as absorbed dose value, radiobiological quantities including relative biological effectiveness (RBE) may also change with the variations of breast tissue composition.

Effective energy assessment during breast cancer intraoperative radiotherapy by low-energy X-rays: A Monte Carlo study.

The study reported in the present paper aimed to evaluate the effective energy (E) of X-rays emitted from the surface of a bare X-ray probe and from different spherical applicators with various diameters, which are widely employed for low kV intraoperative radiotherapy (IORT) of breast cancer. A previously validated Monte Carlo model of the INTRABEAM system along with applicator diameters of 1.5-5 cm (with 0.

Impact of spherical applicator diameter on relative biologic effectiveness of low energy IORT X-rays: A hybrid Monte Carlo study.

Introduction: Low-kV IORT (Low kilovoltage intraoperative radiotherapy) using INTRABEAM machine and dedicated spherical applicators is a candidate modality for breast cancer treatment. The current study aims to quantify the RBE (relative biologic effectiveness) variations of emitted X-rays from the surface of different spherical applicators and bare probe through a hybrid Monte Carlo (MC) simulation approach.

Materials And Methods: A validated MC model of INTRABEAM machine and different applicator diameters, based on GEANT4 Toolkit, was employed for RBE evaluation.

Monte Carlo based analysis and evaluation of energy spectrum for low-kV IORT spherical applicators.

Low-kV IORT is an increasing modality for breast cancer treatment. Soft X-rays from INTRABEAM (Carl Zeiss Meditec AG, Oberkochen, Germany), a dedicated IORT device along with special spherical applicators are employed for this purpose. A Monte Carlo model of INTRAMBEAM and spherical applicators are introduced in the current study to evaluate the dosimetric and physical characteristics of emitted X-rays from the bare probe and different applicator diameters.