JOÃO AUGUSTO MOURA

JOÃO AUGUSTO MOURA

(Fonte: Lattes)

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Possui graduação em Tecnologia em saúde pela Faculdade de Tecnologia de Sorocaba (2005). Mestrado em Tecnologia Nuclear pela Universidade de São Paulo (2009). Doutorado em Tecnologia Nuclear pela Universidade de São Paulo (2015). Tem experiência na área de Tecnologia Nuclear, com ênfase em produção de fontes para radioterapia. Atualmente trabalha em pesquisa e desenvolvimento no Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). (Texto extraído do Currículo Lattes em 8 maio 2023)

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Improvements in the quality control of iridium-192 wire used in brachytherapy
2011 - COSTA, OSVALDO L.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; MOURA, JOÃO A.; FEHER, ANSELMO; MOURA, EDUARDO S.; SOUZA, CARLA D.; SOMESSARI, SAMIR L.
Brachytherapy is a method used in the treatment of cancerous tumors by ionizing radiation produced by sources introduced into the tumor area, this method seeks a more direct attack to the tumor, thereby maximizing the radiation dose to diseased tissue while minimizing the dose to healthy tissues (1). One of the radionuclides used in brachytherapy is iridium-192. The Radiation Technology Center (CTR) of the Nuclear and Energy Research Institute (IPEN) has produced commercially, since 1998, iridium-192 wires used in low dose rate (LDR) brachytherapy (2). To produce this radionuclide, firstly a iridium-platinum wire is irradiated in the nuclear reactor IEA-R1 for 30 hours with a neutron flux of 5 x 1013 ncm-2s-1, the wire is left to decay by 30 days to remove the main contaminants and then goes through a quality control before being sent to the hospital. In this quality control is checked the radiation homogeneity along each centimeter of the wire (3). To implement this procedure is used a device consisting of an ionization chamber surrounded by a lead shield with a small 1 cm wide slit, linked to the ionization chamber is a voltage source and a Keithley 617 electrometer, 2 minutes is the range used to measure the charge by the electrometer. The iridium wire is considered in accordance when there is no variation greater than 5% between the average measures and the maximum and minimum values. However, due to design features of the measurement system, the wire may appear to the detector through the slit in larger sizes than the ideal, improperly influencing the final quality control. This paper calculates the difference in size of these variations in profile and their influence on the final count, it compares the actual values obtained and describes the improvements made in quality control procedures that provided more accurate measurement data, analyzes the results and suggests changes in devices aimed at further improving the quality control of iridium-192 wires produced at IPEN and used in hospitals in Brazil.
A proposal of process validation in the implementation of Good Manufacturing Practices in brachytherapy sources production
2021 - BAPTISTA, TATYANA S.; FEHER, ANSELMO; RODRIGUES, BRUNA T.; ZEITUNI, CARLOS A.; MOURA, JOÃO A.; ROSTELATO, MARIA E.C.M.
New laboratories for brachytherapy sources production are being implemented in our facility at IPEN, in São Paulo. A great challenge implementing a production laboratory is to comply with the Good Manufacturing Practices (GMPs), which involves process validation and all supporting activities such as cleaning and sanitization. Much more than compliance with regulatory guidelines, required for certification and inspections, a validation builds large process knowledge, provides possibilities for optimization and improvement, increasing the degree of maturity of all people involved and the quality system. The process validation results in a document that certifies that any procedure, process, equipment, material, operation, or system leads to the expected results. This work focused on the new laboratory, been assembled to produce small iodine-125 seeds. The process validation was performed three times for evaluation. The parameters evaluated in this study were: the source welding efficiency and the leakage tests results (immersion test). The welding efficiency does not have an established parameter, since is visually evaluated by the operator, and the leakage detection must be under 5 nCi / 185 Bq, accordingly with the ISO 9978. We observed values were average 79-87% production efficiency and leakage tests were under 5 nCi/seed. Although established values for the global efficiency aren’t available in the literature, the results showed high consistency and acceptable percentages, especially when other similar manufacturing processes are used in comparison (average 85-70% found in the literature for other similar metallic structures). Those values will be important data when drafting the validation document and to follow the Good Manufacturing Practices (GMPs).
New core configuration for the fabrication of 125I radioactive sources for cancer treatment
2020 - SOUZA, CARLA D. de; ZEITUNI, CARLOS A.; FEHER, ANSELMO; MOURA, JOÃO A.; COSTA, OSVALDO L. da; ANGELOCCI, LUCAS V.; ROSTELATO, MARIA E.C.M.
In order to provide prostate brachytherapy treatment for more Brazilian men, IPEN is building a laboratory for the manufacture of radioactive sources. The new methodology for the production of iodine-125 seeds with yield 71.7% ± 5.3%. Points of importance were evaluated/discussed: photo-sensibility, reaction vial type, the substitution for iodine-131, pH, and solution volume. The surface was analyzed by FTIR and EDS. At the end, a Monte Carlo-MCNP6 simulation was performed to evaluate the TG-43 parameters.
Waste management protocols for Iridium-192 sources production laboratory used in cancer treatment
2016 - ROSTELATO, MARIA E.C.M.; SOUZA, CARLA D. de; SOUZA, DAIANE C.B. de; ZEITUNI, CARLOS A.; TIEZZI, RODRIGO; COSTA, OSVALDO L. da; RODRIGUES, BRUNA T.; MOURA, JOÃO A.; FEHER, ANSELMO; SORGATTI, ANDERSON; MOURA, EDUARDO S. de; MARQUES, JOSE R. de O.; SANTOS, RAFAEL M. dos; KARAM JUNIOR, DIB
Introduction: Brachytherapy is a form of treatment that uses radioactive seeds placed in contact or inside the region to be treated, maximizing the radiation dose inside the targeted areas. Iridium-192 is being used in brachytherapy since 1955. It presents emission energy in the “therapy region” (370keV) and is easily produced in a nuclear reactor (191Ir (n, γ) → 192Ir). Wires are an iridium-platinum alloy with 0.36 mm diameter and they can be cut in any needed length. They can be used in several types of cancer. The linear activity is between 1 mCi/cm (37 MBq/cm) and 4 mCi/cm (148 MBq/cm) with variations of 10% in 50 cm maximum. This activity values classified the treatment and low dose rate (0,4 à 2 Gy/h). The propose of this work is to present a waste management system in a cancer treatment radioactive sources production laboratory. Methodology and Results: The solid waste is previously characterized in the analysis phase. The contaminants are already known and they are insignificant due to their fast half- life. The iridium-192 half-life is 74.2 days, classified as very short half-life waste. The waste activity is adds to 8mCi (2.96x108 Bq) per wire. According to the CNEN-NN 6.08 standard, that presents the discharge levels, the limit is 1 kBq.kg-1 (2.7x10-5 mCi.kg-1). The radioactive waste generated during the I192 wires production has a weakly activity of 9.7 GBq.g-1. According to the standards, this activity is too high to be discarded into the environment. The waste must be managed following the ALARA principal using the R&R (retain e retard) system, that means, temporary storage and posterior discharge. Since every 4 months, maintenance is performed inside the hot cell used for production, the waste must be removed. Using the equation: 𝐴 = 𝐿 λ (1 − 𝑒−λt), the total calculated activity is 1.68 x 1016 Bq and 4.8 g mass at the end of each 4 months period. This amount is stored inside a shielding device that has 212.37 cm3 volume. The waste will take 9.8 years (calculated by 𝐴 = 𝐴0(𝑒−λt)) to decay to the discharge levels. To store 30 devices during 10 years, a space with 6,370 cm3 is necessary. The laboratory has enough space for this storage. Thus, the radioactive waste management can be performed through the R&R (retain and retard) system safely.
New methodology for binding Iodine-125 onto silver for brachytherapy sources manufacture
2017 - SOUZA, C.D. de; ROSTELATO, M.C.M.; CARDOSO, R.M.; ARAKI, K.; MOURA, J.
Purpose: Cancer is a major health care problem in Brazil and the world. The Brazil’s National Institute for Cancer estimates around 60,000 new prostate cancer cases for 2017. We are assembling a laboratory for production of iodine-125 sources used in prostate brachytherapy in Brazil, since the imported treatment is extremely expensive, thus only available in the private healthcare sector. There are several challenges when developing a laboratory to produce radioactive sources. From choosing a prototype to radiation safety, the task is enormous. The whole production line is full of new process and innovations. Among those, a new chemical reaction that deposit iodine-125 onto silver (core) was developed. This paper presents a new reaction for binding iodine-125 into a silver core. The fixation percentage was calculated by measuring the activity in an ionization chamber. This methodology will be implemented at the iodine-125 sources manufacture laboratory. Methods: Silver cores are washed with an etching solution (100% sulfuric acid) for 5 minutes with sonication. The cores were then placed in sodium sulfate for at least 3 days. They went from a silver matte to a black color. The reaction was allowed to proceed overnight. Each core was individually measured. Results: The yield was 69.2% 7.1%. Considering the silver attenuation is around 20% the results were consider satisfactory. Conclusion: By maximize the reaction yield, we will be able to generate a less costly product that will be available through our public healthcare.
A proposal of process validation in the implementation of good manufacturing practices in brachytherapy sources production
2019 - BAPTISTA, TATYANA S.; FEHER, ANSELMO; RODRIGUES, BRUNA T.; ZEITUNI, CARLOS A.; MOURA, JOÃO A.; ROSTELATO, MARIA E.C.M.
New laboratories for brachytherapy sources production are being implemented in our facility at IPEN, in São Paulo. A great challenge implementing a production laboratory is to comply with the Good Manufacturing Practices (GMPs), which involves process validation and all supporting activities such as cleaning and sanitization. Much more than compliance with regulatory guidelines, required for certification and inspections, a validation builds large process knowledge, provides possibilities for optimization and improvement, increasing the degree of maturity of all people involved and also the quality system as a whole. The process validation results in a document that certifies that any procedure, process, equipment, material, operation or system actually leads to the expected results. This work focused on the new laboratory, been assembled to produce small iodine-125 seeds. The process validation was performed three times for evaluation. The parameters evaluated in this study were: the source welding efficiency and the leakage tests results (immersion test). The welding efficiency doesn’t have an established parameter, since is visually evaluated by the operator, and the leakage detection has to e under 5 nCi / 185 Bq, accordingly with the ISO 9978. We observed values were: average 79-87% production efficiency and leakage tests were under 5 nCi/seed. Although established values for the global efficiency aren’t available in the literature, the results showed high consistency and acceptable percentages, especially when other similar manufacturing processes are used in comparison (average 85-70% found in the literature for other similar metallic structures). Those values will be important data when drafting the validation document and to follow the Good Manufacturing Practices (GMPs).
Waste management protocols for iridium-192 sources production laboratory used in cancer treatment in Brazil
2017 - ROSTELATO, M.E.C.M.; SOUZA, D.C.B.; SOUZA, C.D.; ZEITUNI, C.A.; VICENTE, R.; COSTA, O.L.; RODRIGUES, B.T.; MOURA, J.A.; FEHER, A.; MOURA, E.S.; MARQUES, J.R.O.; CARVALHO, V.S.; NOGUEIRA, B.R.
Objective: The iridium-192 wired sources production results in radioactive waste that needs to follow the guidelines. The aim of this study is to do a radioactive waste management of wastes from iridium-192 sources production laboratory used in cancer treatment in Brazil. Methods: The wire is acquired in an alloy form with 80% platinum and 20% iridium encapsulated with 100%. Electronic microscopy, X-ray fluorescence, and posterior iridium neutron activation (to determine contaminants) are performed to ensure quality. A 50-cm twisted wire is placed in an aluminum tube. The tube is sealed and place inside the reactor irradiator system and is left for decay during 30 hours to wait for the others undesired activation products to decay. The wire is prepared for treatment with 48 cm length with 192 mCi maximum activity. All the equipment use inside the hot cell must be calibrated every four months. All the waste must be removed from the hot cell. Results: The solid waste is previously characterized in the analysis phase. The contaminants are already known and they are insignificant due to their fast half-life. The iridium-192 half-life is 74.2 days, classified as very short half-life waste. The reminiscent activity is 8mCi. Conclusion: The radioactive waste generated during the I192 wires production is solid, was a short half-life and a weakly activity of 9.7 GBq.g-1. According to the standards, this activity is too high to be discarded into the environment (limit 10 Bq.g-1). The waste must be managed by the R&R (retain e retard) system.
Brazilian demand for iodine-125 seeds in cancer treatment after a decade of medical procedures
2017 - COSTA, OSVALDO L. da; SOUZA, DAIANE C.B. de; FEHER, ANSELMO; MOURA, JOAO A.; SOUZA, CARLA D.; OLIVEIRA, HENRIQUE B. de; PELEIAS JUNIOR, FERNANDO S.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.
Brazil radioactive sources production for cancer treatment
2016 - ROSTELATO, MARIA E.; SOUZA, CARLA D.; ZEITUNI, CARLOS A.; MOURA, JOAO A.; MARQUES, JOSE R.O.; COSTA, OSVALDO L.; FEHER, ANSELMO; RODRIGUES, BRUNA T.; SOUZA, DAIANE C.B. de; PELEIAS JUNIOR, FERNANDO S.; SORGATTI, ANDERSON; MOSCA, RODRIGO; MOURA, EDUARDO S. de; ABREU, RODRIGO T.; SOUZA, RAQUEL V. DE; NOGUEIRA, BEATRIZ R.
The modality, known as brachytherapy, was performed in Brazil by only a hand full of hospitals at an extremely high cost. For producing new sources, five major areas must be considered: 1) source production: nuclear activation and/or radiochemical reaction; 2) welding; 3) Quality control: leakage tests; 4) Dosimetry and metrology; 5) Operational procedures; 6) validation studies. To perform all steps, a multidisciplinary team works together to overcome difficulties. - Iridium-192 pellets: In Brazil there are 140 machines with pellets that replacement every 5 years. Our new production line has assembly, welding and quality control hot cells. - Iridium-192 wires: Produced since 1999. The wire is activated at IPENs IEA-R1 reactor for 30 hours with 5x1013 n/cm-2.s-1 neutron flux resulting in 192 mCi maximum activity. - Iridium-192 seed: New seed for ophthalmic cancer treatment. The irradiation device presented 90% activity homogeneity. We are still testing in-vivo. - Iodine-125 seeds: Largely used in low dose brachytherapy. I-125 binding yield achieved with our new reaction was 80%; Laser welding presented 70% efficiency. Approved in all leakage tests. - Other ongoing projects: Veterinary brachytherapy, Waste management, Radionecrosis healing with laser, calibrations sources production, linear accelerator calculations for hospitals, sources with polymeric matrix Our Iodine-125 seeds will be available in 2018. All other projects are advancing. We will continue to develop new products hoping to help the Brazilian population fight against cancer. For producing new sources, five major areas must be considered: 1) source production: nuclear activation and/or radiochemical reaction; 2) welding; 3) Quality control:eakage tests; 4) Dosimetry and metrology; 5) Operational procedures; 6) validation studies. To perform all steps, a multidisciplinary team works together to overcome difficulties
Comparing different methods for radioactive iodine fixation intended for brachytherapy sources manufacture
2016 - SOUZA, CARLA D.; ROSTELATO, MARIA E.C.M.; ZEITUNI, CARLOS A.; PELEIAS JUNIOR, FERNANDO S.; BENEGA, MARCOS A.G.; MOURA, JOAO A.; FEHER, ANSELMO; COSTA, OSVALDO L.; TIEZZI, RODRIGO; RODRIGUES, BRUNA T.; SILVA, THAIS H. da; SORGATTI, ANDERSON; SOUZA, DAIANE C.B. de
Brachytherapy, a method of radiotherapy, is being extensively used in the early and intermediate stages of the illness. In this treatment, radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope iodine-125, fixated on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16%; method 2 (chemical reaction based on the method developed by David Kubiatowicz - HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80%. Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN.