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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.
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.
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
Experiment to access Iodine-125 leakage in different vials
2017 - SOUZA, C.D. de; ROSTELATO, M.C.M.; ZEITUNI, C.; COSTA, O. da; RODRIGUES, B.T.; GONZALEZ, A.C.; MARQUES, J. de O.
Purpose: There are several challenges when developing a laboratory to produce radioactive sources. From choosing a prototype to radiation safety, the task is enormous. During the past 15 years, our research group is developing a laboratory to produce iodine-125 seed. These seeds are placed inside the cancer and release radiation directly in the target. 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 comparison between vials in order to access their capability to retain radioactive iodine. Also, the fixation percentage in a silver core was taken into account. This information will be used to select a vial to be implemented at the iodine-125 sources manufacture laboratory. Methods: Vials made with polymers and glass was tested. Iodine-125 were placed in the vials overnight at rt. Seven vials with different materials (glass, dark glass, and plastics) were evaluated. Results: The selected vial (borosilicate glass 1 mL total volume) loss 17.61% of iodine in 24 hours and presented the highest iodine intake. It was noticeable that the vial material influenced both iodine intake and iodine loss. The goal is to maximize the reaction yield to result in a less costly product. Conclusion: We have selected the best vial for our reaction in regards to leakage and yield.
Surface coating and study of metallic cores for radioactive sources production used in cancer treatment
2016 - ROSTELATO, M.E.C.M.; SOUZA, C.D.; ZEITUNI, C.A.; MATTOS, F.R.; MARQUES, J.R.O.; MOURA, J.A.; FEHER, A.; COSTA, O.L.; SOUZA, D.C.B.; TIEZZI, R.; RODRIGUES, B.T.; KARAM JUNIOR, D.
Developing new and innovative treatments for cancer is an urgent matter. The National Institute of Cancer estimates that Brazil will have 576,000 new cases of the disease in 2015. Our research group is developing new radioactive seeds to be use in radiotherapy procedures since the early 2000’s. We present the surface study and research for two of our major projects: iodine-125 seeds for prostate, brain and eye cancer treatment and iridium-192 for eyecancer treatment.
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.
Desenvolvimento da metodologia para sintese do poli-)acido latico-co-acido glicolico) para utilização na produção de fontes radioativas
2015 - PELEIAS JUNIOR, FERNANDO dos S.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; FECHINE, GUILHERMINO J.M.; SOUZA, CARLA D. de; MATTOS, FABIO R. de; MOURA, EDUARDO S. de; MOURA, JOAO A.; BENEGA, MARCOS A.G.; FEHER, ANSELMO; COSTA, OSVALDO L. da; RODRIGUES, BRUNA T.
A Organização Mundial da Saúde (OMS) relata o câncer como uma das principais causas de morte no mundo. Uma modalidade de tratamento que vem sendo bastante utilizada no tratamento do câncer de próstata é a braquiterapia, que consiste na introdução de sementes com material radioativo no interior do orgão. Sementes de Iodo-125 podem ser inseridas soltas ou em cordas poliméricas fabricadas a partir do (poli(ácido lático-co-ácido glicólico)) (PLGA). Foi proposto neste trabalho, o estudo e desenvolvimento da metodologia de síntese do biopolímero PLGA. Os resultados obtidos demonstram que, através da metodologia utilizada, foi possível determinar os melhores parâmetros de reação (tempo e temperatura) para o PLGA na proporção 80/20 (lactídeo/glicolídeo). Com uma temperatura de 110 °C e tempo de reação 72h o rendimento da reação é superior a 90%. Os valores de massas moleculares obtidas entre os testes, ainda são baixos quando comparados com os valores obtidos por outros autores na literatura. Novos testes estão sendo conduzidos, utilizando dímeros preparados no laboratório. Testes substituindo o vácuo por uma atmosfera de nitrogênio também estão sendo realizados. Essas duas substituições podem aumentar o valor final da massa molecular do polímero. Em relação à caracterização, as técnicas utilizadas confirmaram a estrutura esperada do polímero.
Assessment of the risks associated with iodine-125 handling production sources for brachytherapy
2015 - SOUZA, DAIANE C.B.; ROSTELATO, MARIA E.C.; VICENTE, ROBERTO; ZEITUNI, CARLOS A.; TIEZZI, RODRIGO; COSTA, OSVALDO L.; SOUZA, CARLA D.; PELEIAS JUNIOR, FERNANDO S.; RODRIGUES, BRUNA T.; SOUZA, ANDERSON S.; KARAM JUNIOR, DIB; BATISTA, TALITA Q.; MELO, EMERSON R.; CAMARGO, ANDERSON R.
Development of sealed radioactive sources immobilized in epoxy resin for verification of detectors used in nuclear medicine
2015 - TIEZZI, RODRIGO; ROSTELATO, MARIA E.C.M.; NAGATOMI, HELIO R.; ZEITUNI, CARLOS A.; BENEGA, MARCOS A.; SOUZA, DAIANE B. de; COSTA, OSVALDO L. da; SOUZA, CARLA D.; RODRIGUES, BRUNA T.; SOUZA, ANDERSON S. de; PELEIAS JUNIOR, FERNANDO S.; SANTOS, RAFAEL M. dos; MELO, EMERSON R. de; KARAN JUNIOR, DIB