LUCAS VERDI ANGELOCCI
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Resumo IPEN-doc 31144 Dose rate by distance for Au-198 nanoparticles in water2024 - ANGELOCCI, L.V.; SGRIGNOLI, S.S.; SOUZA, C.D.; TEODORO, L.E.H.; ZEITUNI, C.A.; ROSTELATO, M.E.C.M.Purpose: To evaluate dose as a function of depth in water medium by a source of Au-198 nanoparticles, both as a point source and as homogeneously distributed over a volume representing a prostate tumor. Dose over an unidirectional axis was estimated and presented according to distance from the source, highlighting nearby organs at risk. The aim of the work is the first step in the dosimetric characterization of a new source for nanobrachytherapy under development, consisting of Au-198 nanoparticles injected directly in tumoral mass. Methods: Simulations were carried using MCNP6.2 code by Los Alamos National Laboratory. Four different simulations were realized, for two different source configurations (point source and 0.4 cm radius spherical source, modeling a prostate tumor) each considering two different components for the dose (beta emission and photon (gamma/x-ray) emission from the source). Medium considered was infinite water homogeneous. Results: Dose curve as a function of distance from the source was evaluated and allowed a first estimative of dose at points of interest for treatment with a new nanobrachytehrapy source. Point source results are valuable for future extrapolation for complex tumor/organs geometry. Prostate tumor model presents data that allows to estimate dose at center of tumor, borders of tumor, and at other organs nearby, such as rectum and bladder. Conclusion: Being a beta-emitter, Au-198 shows a high deposition of energy near the source, with doses falling significantly with distance from the source. However, due to gamma and x-ray emission from the source, as well as secondary radiation originating from the beta particles, not-negligible dose was scored at significant distance. This quantitative study will be relevant for posterior dosimetry of more complex cases as well to develop protocols for dosimetry and clinical use, as nanobrachytherapy (with nanoparticles as sources) is a relatively new field with few specific works published.Resumo IPEN-doc 26910 Efficiancy of hydrogen peroxide for cleaning production areas and equipments in the Laboratory for Brachyterapy Sources Production2017 - BAPTISTA, T.; ROSTELATO, M.C.M.; ZEITUNI, C.; PERINI, E.A.; SOUZA, C.D. de; MARQUES, J. de O.; NOGUEIRA, B.R.; ANGELOCCI, L.V.Purpose: A great challenge in the brachytherapy sources production is to fulfill the Good Manufacturing Practices (GMPs) requirements, involving the process validation and of all supporting activities such as cleaning and sanitization. The increasingly strict requirements for quality assurance system, with several norms, normative resolutions and rules that must follow both medical products and radiochemical requirements, has led to a constant validation concerns. The main goal of GMP is to reduce inherent risks such as product contamination with microorganisms and cross-contamination. Methods: In the Laboratory for Brachytherapy Sources Production it was established a cleaning program for cleanrooms and hot cells using a hydrogen peroxide solution (6%). This work aims to assess the effectiveness of this cleaning agent in reducing and/or eliminating microbial load into the cleanrooms and equipments to acceptable levels in accordance with the current legislation. Results: The analysis was conducted using the results of the environmental monitoring program with settling contact plates in cleanrooms after the cleaning procedures. Furthermore, it was possible to evaluate the action of the sanitizing agent on the microbial population at the equipment and cleanrooms’ surfaces. It was also evaluated the best way to accomplish the cleaning program considering the dosimetry factor in each production process, hence the importance of radiological contamination. All the following environmental monitoring procedures presented satisfactory results, showing that the cleaning procedures was able to reduce and maintain the acceptable levels of viable and non-viable particles for the cleanroom classification (ISO 5 and ISO 7). The cleaning process with this sanitizer (hydrogen peroxide) can be performed quickly right before the production; allowing the production of brachytherapy sources without after use residues. Conclusion: This data will help the production of a clean and reliable product.