Monte Carlo simulation of a TEPC for microdosimetry of carbon ions

Galer, S.; Shipley, D R; Kirkby, K.J.; Nisbet, Andrew

doi:10.1016/j.radphyschem.2017.02.028

Cited by 6 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optimization of a MC tool to interpret experimental microdosimetric spectra can be useful for testing new detectors or new experimental set ups. Previous studies have also been done with this aim in different radiation fields, with different detectors and different MC codes (Rollet et al 2010, Bohlen et al 2012, Chiriotti et al 2014, Chiriotti et al 2017, Galer et al 2017. In this paper, the microdosimetric extension of TOPAS (Perl et al 2012, Zhu et al 2019 was used to simulate the response of a mini-TEPC that measured in the 62 MeV mono-energetic proton beam of the clinical CATANA facility at the Southern National Laboratories (LNS) of INFN (Cirrone et al 2004).…”

Section: Introductionmentioning

confidence: 99%

TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data

Bianchi¹,

Selva²,

Reniers³

et al. 2023

Phys. Med. Biol.

View full text Add to dashboard Cite

Objective: Microdosimetry offers a fast tool for radiation quality (RQ) verification to be implemented in treatment planning systems in proton therapy based on variable LET or RBE to move forward from the use of a fixed RBE of 1.1. It is known that the RBE of protons can increase up to 50% higher than that value in the last few millimetres of their range. Microdosimetry can be performed both experimentally and by means of Monte Carlo (MC) simulations. This paper has the aim of comparing the two approaches. Approach: Experimental measurements have been performed using miniaturized Tissue Equivalent Proportional Counters (mini-TEPCs) developed at the Legnaro National Laboratories of the Italian National Institute for Nuclear Physics (LNL-INFN) with the aim of being used as RQ monitors for high intensity beams. MC simulations have been performed using the microdosimetric extension of TOPAS which provides optimized parameters and scorers for this application. Main results: Simulations were compared with experimental microdosimetric spectra in terms of shape of the spectra and their average values. Moreover, the latter have been investigated as possible estimators of LET obtained with the same MC code. The shape of the spectra is in general consistent with the experimental distributions and the average values of the distributions in both cases can predict the RQ increase with depth. Significance: This study aims at the comparison of microdosimetric spectra obtained from both experimental measurements and the microdosimetric extension of TOPAS in the same radiation field.

show abstract

Section: Introductionmentioning

confidence: 99%

TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data

Bianchi¹,

Selva²,

Reniers³

et al. 2023

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…Microdosimetric measurements offer a valuable method to characterize the complexities of a radiation field and to assess relative biological effectiveness (RBE) values by applying a biological weighting function approach (Coutrakon et al 1997, Paganetti et al 1997, Gerlach et al 2002, De Nardo et al 2004b, Endo et al 2007 or the microdosimetric kinetic (MK) model (Kase et al 2006, Tran et al 2017 to the measured microdosimetric spectra. Monte Carlo (MC) simulations can be a valuable supplement to experimental microdosimetric measurements to investigate microdosimetric characteristic of different kinds of charged particles and scenarios once they are validated with a set of initial experiments (Böhlen et al 2011, 2012, Burigo et al 2014, Dewey et al 2017, Galer et al 2017.…”

Section: Introductionmentioning

confidence: 99%

The microdosimetric extension in TOPAS: development and comparison with published data

et al. 2019

View full text Add to dashboard Cite

Microdosimetric energy depositions have been suggested as a key variable for the modeling of the relative biological effectiveness (RBE) in proton and ion radiation therapy. However, microdosimetry has been underutilized in radiation therapy. Recent advances in detector technology allow the design of new mico-and nano-dosimeters. At the same time Monte Carlo simulations have become more widely used in radiation therapy. In order to address the growing interest in the field, a microdosimetric extension was developed in TOPAS. The extension provides users with the functionality to simulate microdosimetric spectra as well as the contribution of secondary particles to the spectra, calculate microdosimetric parameters, and determine RBE with a biological weighting function approach or with the microdosimetric kinetic model. Simulations were conducted with the extension and the results were compared with published experimental data and other simulation results for three types of microdosimeters, a spherical tissue equivalent proportional counter (TEPC), a cylindrical TEPC and a solid state microdosimeter. The corresponding microdosimetric spectra obtained with TOPAS from the plateau region to the distal tail of the Bragg curve generally show good agreement with the published data.

show abstract

“…Then, the conversion method was derived according to the Chapman–Kolmogorov equation and the scaling factor. As some researches 10–12 have demonstrated that the results from the Geant4 simulation agree well with the experimental data in microdosimetry, this work was carried out by the Geant4 simulation.…”

Section: Introductionmentioning

confidence: 55%

A method for converting microdosimetric spectra in diamond to tissue in proton therapy

Fan

Tang

et al. 2022

Medical Physics

View full text Add to dashboard Cite

Purpose Diamond has been regarded as a promising microdosimeter in radiation protection and radiotherapy due to its excellent properties. However, as the diamond is not tissue equivalent, a conversion of the measured spectra in the diamond microdosimeter to the tissue site is needed. In this work, we intend to deduce a method for converting the microdosimetric spectra from diamond to tissue in the proton therapy application based on the Chapman–Kolmogorov equation and investigate the validity of this method in spectral conversion. Methods The comparison of stopping power and energy deposition distribution of diamond and tissue shows that the conversion of the spectra in diamond to tissue can be performed by a simple scaling factor. Therefore, the equivalence of the energy deposition spectra in the diamond microdosimeter and a tissue site of the same size in the same radiation field was studied first to obtain the scaling factor. Then, the spectra conversion method was derived from the Chapman–Kolmogorov equation and the scaling factor. The Geant4 simulation was employed to settle this study. Results Theoretical and Geant4 simulation results indicate that the linear stopping power ratio of diamond to tissue is adequate to convert the microdosimetric spectra in diamond to tissue of identical dimension. The conversion results indicate that the energy deposition spectra converted from diamond to bone agree well with the spectra calculated by Geant4 along the Bragg curve. As for water, a good agreement of the converted and calculated spectra was found at the plateau of the Bragg curve and the distal part of the Bragg peak. At the proximal part of the Bragg peak, the converted and calculated spectrum is poorly coincident. Conclusions The method of the energy deposition spectra conversion from the diamond microdosimeter to the tissue site of equal size shows relatively good results in most situations. But the deficiency was also found. Therefore, further investigation is needed to improve the reliability of this method.

show abstract

Monte Carlo simulation of a TEPC for microdosimetry of carbon ions

Cited by 6 publications

References 19 publications

TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data

TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data

The microdosimetric extension in TOPAS: development and comparison with published data

A method for converting microdosimetric spectra in diamond to tissue in proton therapy

Contact Info

Product

Resources

About