Desenvolvimento de um fantoma antropomórfico e antropométrico feminino de corpo inteiro em impressão 3D para calibração de um sistema contador de corpo inteiro

Abstract

Whole-body counters (WBCs) are used in internal dosimetry for in vivo monitoring bioassays. The calibration processes of a WBC setup include measuring a physical phantom filled with a certified radioactive source. The aim of this study was to develop an anthropomorphic and anthropometric female physical phantom for calibrating WBC systems to reduce associated uncertainties in the system. The ICRP's Reference Female Phantom for Internal Dosimetry (RFPID), previously referred to as the ICRP female computational phantom, was 3D-printed using PLA filament and hollow inside to be filled with ballistic gel. Ballistic gel is widely implemented as tissue equivalent for ballistic studies; however, it still lacks comprehensive characterization in terms of chemical composition, physical, and radiological properties to designate it as an ideal substitute tissue for dosimetry. Tests were conducted on the ballistic gel to determine its density and attenuation coefficients. The gel was then compared with muscle, water, PMMA, and NIST XCOM attenuation coefficient data based on its composition. The RFPID was subsequently modeled and simulated using the MCNP6.2 code, filled with ballistic gel, and placed in a WBC equipped with a previously validated NaI(Tl) 8”x4” scintillator detector. The simulation was repeated using the ICRP-110 RCP_AF for comparison purposes. The study findings indicate that the RFPID printed in PLA and filled with ballistic gel may serve as a calibration phantom for whole-body counter systems. However, experimental validation with the physical model is necessary to confirm the results when the simulator is filled with ballistic gel containing an Eu-152 source. Therefore, future work aims to add Eu-152 to the ballistic gel to fill the 16 compartments of the RFPID, which will be used for calibrating the LDI/CDTN/CNEN WBC in Minas Gerais, Brazil.