PURPOSE: To generate and validate a source model of a miniature X-ray generator (INTRABEAM, Carl Zeiss Surgical, Oberkochen, Germany) for endovaginal TARGeted Intra-operative radioTherapy (TARGIT) brachytherapy a Geant4-based Monte Carlo (MC) tool was developed. The model was used to calculate the accurate relative dose distribution for the source combined with a cylindrical applicator which was developed for endovaginal treatment. METHODS AND MATERIALS: Geometries with given materials of the X-ray source and applicator were implemented in a Geant4-based dose calculation framework. To reduce the calculation time, phase space files for a set of circular electron beam foci and different beam radii were precalculated. Different beam radii had to be considered because the exact electron beam path on the target is not known in advance. To estimate the electron beam radius distribution of the system, a least squares minimization between the EBT film measured relative dose distribution and the simulation was performed. RESULTS: Relative dose distributions were calculated and compared with Gafchromic EBT film measurements to validate the MC method. In a region of interest around the source, the 2%/2mm gamma criterion matched with 98%. Profiles showed excellent agreement between measurement and simulation. The calculation time to simulate an entire treatment was twelve minutes. CONCLUSIONS: The method was able to predict the radius and width of the trajectory where the electrons impact on the target. This enables the complete simulation. The developed method allows calculating relative dose distributions for endovaginal TARGIT brachytherapy matching measured relative dose distributions within clinically acceptable limits.
PURPOSE: To generate and validate a source model of a miniature X-ray generator (INTRABEAM, Carl Zeiss Surgical, Oberkochen, Germany) for endovaginal TARGeted Intra-operative radioTherapy (TARGIT) brachytherapy a Geant4-based Monte Carlo (MC) tool was developed. The model was used to calculate the accurate relative dose distribution for the source combined with a cylindrical applicator which was developed for endovaginal treatment. METHODS AND MATERIALS: Geometries with given materials of the X-ray source and applicator were implemented in a Geant4-based dose calculation framework. To reduce the calculation time, phase space files for a set of circular electron beam foci and different beam radii were precalculated. Different beam radii had to be considered because the exact electron beam path on the target is not known in advance. To estimate the electron beam radius distribution of the system, a least squares minimization between the EBT film measured relative dose distribution and the simulation was performed. RESULTS: Relative dose distributions were calculated and compared with Gafchromic EBT film measurements to validate the MC method. In a region of interest around the source, the 2%/2mm gamma criterion matched with 98%. Profiles showed excellent agreement between measurement and simulation. The calculation time to simulate an entire treatment was twelve minutes. CONCLUSIONS: The method was able to predict the radius and width of the trajectory where the electrons impact on the target. This enables the complete simulation. The developed method allows calculating relative dose distributions for endovaginal TARGIT brachytherapy matching measured relative dose distributions within clinically acceptable limits.
Authors: Arne Mathias Ruder; Laurens Inghelram; Frank Schneider; Gustavo R Sarria; Jürgen Hesser; Frederic Bludau; Udo Obertacke; Frederik Wenz; Yasser Abo-Madyan; Frank A Giordano Journal: J Contemp Brachytherapy Date: 2020-10-30
Authors: Carsten Herskind; Lin Ma; Qi Liu; Bo Zhang; Frank Schneider; Marlon R Veldwijk; Frederik Wenz Journal: Radiat Oncol Date: 2017-01-19 Impact factor: 3.481
Authors: Frank Schneider; Sven Clausen; Johannes Thölking; Frederik Wenz; Yasser Abo-Madyan Journal: J Appl Clin Med Phys Date: 2014-01-06 Impact factor: 2.102