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Preclinical photon minibeam radiotherapy using a custom collimator: Dosimetry characterization and preliminary in-vivo results on a glioma model.

Authors :
Koksal Akbas, Canan
Vurro, Federica
Fiorino, Claudio
Cozzarini, Cesare
Cavaliere, Francesco
Milani, Paolo
Broggi, Sara
Del Vecchio, Antonella
Di Muzio, Nadia
Tacchetti, Carlo
Enrico Spinelli, Antonello
Source :
Physica Medica; Aug2024, Vol. 124, pN.PAG-N.PAG, 1p
Publication Year :
2024

Abstract

• Development of Custom minibeam collimator. • Dosimetry characteristics evaluated by EBT3 films and TOPAS Monte Carlo. • In vivo experiment using a glioma preclinical model. The purpose of this study is to investigate the dosimetric characteristics of a collimator for minibeam radiotherapy (MBRT) with film dosimetry and Monte Carlo (MC) simulations. The outcome of MBRT with respect to conventional RT using a glioma preclinical model was also evaluated. A multi-slit collimator was designed to be used with commercial small animal irradiator. The collimator was built by aligning 0.6 mm wide and 5 mm thick parallel lead leaves at 0.4 mm intervals. Dosimetry characteristics were evaluated by Gafchromic (CG) films and TOPAS Monte Carlo (MC) code. An in vivo experiment was performed using a glioma preclinical model by injecting two million GL261cells subcutaneously and treating with 25 Gy, single fraction, with MBRT and conventional RT. Survival curves and acute radiation damage were measured to compare both treatments. A satisfactory agreement between experimental results and MC simulations were obtained, the measured FWHM and distance between the peaks were respectively 0.431 and 1.098 mm. In vivo results show that MBRT can provide local tumor control for three weeks after RT treatment and a similar survival fraction of open beam radiotherapy. No severe acute effects were seen for the MBRT group. We developed a minibeam collimator and presented its dosimetric features. Satisfactory agreement between MC and GC films was found with differences consistent with uncertainties due to fabrication and set-up errors. The survival curves of MBRT and open field RT are similar while atoxicity is dramatically lower with MBRT, preliminarily confirming the expected effect. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
11201797
Volume :
124
Database :
Supplemental Index
Journal :
Physica Medica
Publication Type :
Academic Journal
Accession number :
178884844
Full Text :
https://doi.org/10.1016/j.ejmp.2024.103420