Development and experimental characterization of a block copolymer styrene-ethylene/butylene-styrene (SEBS) gel dosimeter for clinical dosimetry applications

• Grant number: 17/02032-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2017
• End date: June 30, 2018
• Field of knowledge: Health Sciences - Medicine - Medical Radiology
• Principal Investigator: Theo Zeferino Pavan
• Grantee: Lucas Sacchini Del Lama
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 13/18854-6 - Photoacoustic and ultrasound imaging applied to tissue characterization, AP.JP

Abstract

In medicine, several materials have already been proposed for the composition of phantoms in order to mimic biological tissue for both diagnostic and therapeutic modalities. More specifically in radiotherapy, one must determine both the absorbed dose and its distribution in order to achieve adequate tumor control and lower complications in healthy patient tissues. Current and conventionally methods to perfor dosimetry are inherently 1D or 2D and the use of those dosimeters involve disturbances of the radiation beam, implying the use of correction factors. In general, gel dosimetry presents useful features that facilitate dosimetry, such as the ability to quantify three-dimensionally absorbed dose distributions, to determine the absorbed dose with less dependence on the dose rate for a considerable range of rates, the possibility of being tissue equivalent, presents high spatial resolution and has no energy dependence for keV up to MeV ranges. Styrene-ethylene/butylene-styrene (SEBS) block copolymer gel materials comprise a class of thermoreversible gels with a large number of applications in the industry and with great potential to be studied because of several optical and mechanical properties such as translucency, low diffusion, low temporal fade and easy preparation. In this sense, the general objective of this work is the development and evaluation of a gel dosimeter with tissue properties, based on SEBS, which allows quantification and mapping of the absorbed dose in tests/treatments employing ionizing radiation considering a practical approach that allows the extraction of dosimetric parameters in order to generate images and obtain data through ultrasound, elastography or optics that provide suitable information content for clinical radiation beams.