Consuelo Guardiola1, Ludovic De Marzi2,3, Yolanda Prezado1. 1. Centre National de la Recherche Scientifique (CNRS); Universités Paris 11 and Paris 7, Laboratoire d'Imagerie et Modélisation en Neurobiologie et Cancérologie (IMNC), Orsay Cedex, 91405, France. 2. Institut Curie, PSL Research University, Centre de protonthérapie d'Orsay, Campus universitaire, bâtiment 101, Orsay 91898, France. 3. Institut Curie, University Paris Saclay, PSL Research University, Inserm U 1021-CNRS UMR 3347, Orsay, France.
Abstract
OBJECTIVES: Proton minibeam radiation therapy (pMBRT) is a novel therapeutic strategy that combines the benefits of proton therapy with the remarkable normal tissue preservation observed with the use of submillimetric spatially fractionated beams. This promising technique has been implemented at the Institut Curie-Proton therapy centre (ICPO) using a first prototype of a multislit collimator. The purpose of this work was to develop a Monte Carlo-based dose calculation engine to reliably guide preclinical studies at ICPO. METHODS: The whole "Y1"-passive beamline at the ICPO, including pMBRT implementation, was modelled using the Monte Carlo GATE v. 7.0 code. A clinically relevant proton energy (100 MeV) was used as starting point. Minibeam generation by means of the brass collimator used in the first experiments was modelled. A virtual source was modelled at the exit of the beamline nozzle and outcomes were compared with dosimetric measurements performed with EBT3 gafchromic films and a diamond detector in water. Dose distributions were recorded in a water phantom and in rat CT images (7-week-old male Fischer rats). RESULTS: The dose calculation engine was benchmarked against experimental data and was then used to assess dose distributions in CT images of a rat, resulting from different irradiation configurations used in several experiments. It reduced computational time by an order of magnitude. This allows us to speed up simulations for in vivo trials, where we obtained peak-to-valley dose ratios of 1.20 ± 0.05 and 6.1 ± 0.2 for proton minibeam irradiations targeting the tumour and crossing the rat head. Tumour eradication was observed in the 67 and 22% of the animals treated respectively. CONCLUSION: A Monte Carlo dose calculation engine for pMBRT implementation with mechanical collimation has been developed. This tool can be used to guide and interpret the results of in vivo trials. ADVANCES IN KNOWLEDGE: This is the first Monte Carlo dose engine for pMBRT that is being used to guide preclinical trials in a clinical proton therapy centre.
OBJECTIVES: Proton minibeam radiation therapy (pMBRT) is a novel therapeutic strategy that combines the benefits of proton therapy with the remarkable normal tissue preservation observed with the use of submillimetric spatially fractionated beams. This promising technique has been implemented at the Institut Curie-Proton therapy centre (ICPO) using a first prototype of a multislit collimator. The purpose of this work was to develop a Monte Carlo-based dose calculation engine to reliably guide preclinical studies at ICPO. METHODS: The whole "Y1"-passive beamline at the ICPO, including pMBRT implementation, was modelled using the Monte Carlo GATE v. 7.0 code. A clinically relevant proton energy (100 MeV) was used as starting point. Minibeam generation by means of the brass collimator used in the first experiments was modelled. A virtual source was modelled at the exit of the beamline nozzle and outcomes were compared with dosimetric measurements performed with EBT3 gafchromic films and a diamond detector in water. Dose distributions were recorded in a water phantom and in rat CT images (7-week-old male Fischer rats). RESULTS: The dose calculation engine was benchmarked against experimental data and was then used to assess dose distributions in CT images of a rat, resulting from different irradiation configurations used in several experiments. It reduced computational time by an order of magnitude. This allows us to speed up simulations for in vivo trials, where we obtained peak-to-valley dose ratios of 1.20 ± 0.05 and 6.1 ± 0.2 for proton minibeam irradiations targeting the tumour and crossing the rat head. Tumour eradication was observed in the 67 and 22% of the animals treated respectively. CONCLUSION: A Monte Carlo dose calculation engine for pMBRT implementation with mechanical collimation has been developed. This tool can be used to guide and interpret the results of in vivo trials. ADVANCES IN KNOWLEDGE: This is the first Monte Carlo dose engine for pMBRT that is being used to guide preclinical trials in a clinical proton therapy centre.
Authors: E Seravalli; C Robert; J Bauer; F Stichelbaut; C Kurz; J Smeets; C Van Ngoc Ty; D R Schaart; I Buvat; K Parodi; F Verhaegen Journal: Phys Med Biol Date: 2012-03-07 Impact factor: 3.609
Authors: A K Mandapaka; A Ghebremedhin; B Patyal; Marco Marinelli; G Prestopino; C Verona; G Verona-Rinati Journal: Med Phys Date: 2013-12 Impact factor: 4.071
Authors: A Niroomand-Rad; C R Blackwell; B M Coursey; K P Gall; J M Galvin; W L McLaughlin; A S Meigooni; R Nath; J E Rodgers; C G Soares Journal: Med Phys Date: 1998-11 Impact factor: 4.071
Authors: Slobodan Devic; Jan Seuntjens; Edwin Sham; Ervin B Podgorsak; C Ross Schmidtlein; Assen S Kirov; Christopher G Soares Journal: Med Phys Date: 2005-07 Impact factor: 4.071
Authors: F Marsolat; L De Marzi; A Patriarca; C Nauraye; C Moignier; M Pomorski; F Moignau; S Heinrich; D Tromson; A Mazal Journal: Phys Med Biol Date: 2016-08-08 Impact factor: 3.609