New article published in 13(2A) - SENCIR 2025

Reference Male Phantom for Internal Dosimetry-RMPID: Physical model in 3D-printing for whole-body counter calibration

Abstract: In vivo internal dosimetry can use a whole-body counter (WBC) to estimate radionuclides' incorporated activity (Bq) in internally contaminated individuals. The WBC must be calibrated to convert the count rate from the detector into activity incorporated in the person. Active physical phantoms could be used for the calibration procedure. Additive manufacturing allows the physical reproduction of ICRP computational models with good geometric fidelity. This study aims to develop imaging manipulation techniques to generate stereolithography (STL) parts for the 3D printing a male physical phantom based on the Adult Male Reference Computational Phantom (RCP_AM) model provided in the ICRP 110 publication. The Reference Male Phantom for Internal Dosimetry (RMPID) was developed based on the model provided by the ICRP in text file format containing the RCP_AM segmentation information. It was processed with an in-house C++ program that generated images in RAW format (Unprocessed images). The images were manipulated using freeware: ImageJ, MeshLab, FreeCAD, and Meshmixer. A set of 22 hollow portions, 44 pieces including the lids, which fit together, were obtained. The RMPID was printed in PLA (Polylactic Acid) on the Creality Ender 5 Plus 3D printer. The 3D-printed phantom parts passed leak tests, proving that imaging manipulation techniques resulted in well-sealed parts. That will allow the phantom to be safely filled with tissue-equivalent material containing a calibrated activity of the selected radionuclide. The design also makes the simulator easier to handle and to assemble during calibration routines. Read full article. 

Radiation-induced copper oxide formation in a clinical gel composite: a novel approach for dosimetry

Abstract: This research is intended to investigate radiation-induced changes in a clinical gel composite with copper sulfate pentahydrate (CuSO₄·5H₂O). This study aimed to investigate the mechanisms was to understand the mechanisms of interaction between radiation and the material, within the proposal to develop accessible dosimetric materials that can efficiently monitor radiation doses. The samples were previously studied by ultraviolet-visible (UV-Vis) spectroscopy, demonstrating their potential for dosimetric use. For this work, the material was irradiated with gamma doses of 30 and 100 kGy and analyzed by nuclear magnetic resonance (NMR) spectroscopy and Raman spectroscopy. It was observed that the color of the samples changes from blue to red with increasing radiation dose, suggesting the formation of copper oxides. NMR analysis revealed changes in longitudinal (T1) and transverse (T2) relaxation times, indicating interactions between the gel matrix and copper sulfate. Raman spectroscopy confirmed the formation of new peaks associated with the presence of copper oxides. pH measurements were also performed to corroborate the results. Read full article.