Objective:To observe the possibility of neoplasm needle track implantation after radioactive seeds implantation and seek preventive measures to avoid it.Methods:Superficial tissue of 250 seeding needle cores and 250 s...Objective:To observe the possibility of neoplasm needle track implantation after radioactive seeds implantation and seek preventive measures to avoid it.Methods:Superficial tissue of 250 seeding needle cores and 250 stylophores employed in neoplasm radioactive seeds implantation was smeared on slides to search for tumor cells.All patients received chemotherapy or endocrine therapy after operations.Ultrasound B-mode or computer tomography(CT)was performed at 10th day,30th day,60th day,and 180th day post operation to detect neoplasm implantation metastasis through needle tracks. Results:Positive cells were found on 13 of 250(5.20%)cores,and 7 of 250(2.80%)stylophores.The difference was not sta- tistically significant(P>0.05).The positive cells frequency of needles those traversed distance less than 3 cm in normal tissue was 6.19%(13/210),while the frequency of the others those traversed longer distance in normal tissue was 2.41%(7/290). The positive cells frequency of needles traversing different distances in normal tissues is significantly different(P<0.05).No neoplasm was detected through needle tracks by ultrasound B-mode or CT in 180 days after operation.Conclusion:Tumor cells could ablate into the needle track during radioactive seed implantation.Some preventive measures,such as optimization of pre-operation and intra-operation treatment plan,chemotherapy or endocrine therapy after operation,may be beneficial to avoid the implantation metastasis of neoplasm in seeding needle tracks.展开更多
Charge breeding technique is used for RIB （radioactive ion beam） production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is ach...Charge breeding technique is used for RIB （radioactive ion beam） production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1＋ to a desired value n＋. In some experiments, a continuous RIB of a given energy may be required. To reach this goal, a charge breeding device based on a hollow gun EBIS （electron beam ion source） has been proposed by the author recently. That EBIS, in principle, can be capable to realize a CW （continuous wave） operation. A sufficiently high focusing magnetic field could reduce to zero the hole radius in the EBIS electron beam. However, a smaller efficiency in the ion charge state increase should be expected. A code developed for studying the ion selective containment in a EBIS has been modified and used to simulate the ion charge state breeding. The effects of the hollow electron beam on the breeding rate have been studied.展开更多
In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase o...In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.展开更多
The objective of this work is to develop an automation system for quality control （QC） in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding （LBW）. These sources, also ...The objective of this work is to develop an automation system for quality control （QC） in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding （LBW）. These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of lodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller （PLC）, step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices （GMP）. Nowadays, the Radiation Technology Centre at IPEN-CNEN/SP imports and distributes 36,000 lodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 lodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil.展开更多
文摘Objective:To observe the possibility of neoplasm needle track implantation after radioactive seeds implantation and seek preventive measures to avoid it.Methods:Superficial tissue of 250 seeding needle cores and 250 stylophores employed in neoplasm radioactive seeds implantation was smeared on slides to search for tumor cells.All patients received chemotherapy or endocrine therapy after operations.Ultrasound B-mode or computer tomography(CT)was performed at 10th day,30th day,60th day,and 180th day post operation to detect neoplasm implantation metastasis through needle tracks. Results:Positive cells were found on 13 of 250(5.20%)cores,and 7 of 250(2.80%)stylophores.The difference was not sta- tistically significant(P>0.05).The positive cells frequency of needles those traversed distance less than 3 cm in normal tissue was 6.19%(13/210),while the frequency of the others those traversed longer distance in normal tissue was 2.41%(7/290). The positive cells frequency of needles traversing different distances in normal tissues is significantly different(P<0.05).No neoplasm was detected through needle tracks by ultrasound B-mode or CT in 180 days after operation.Conclusion:Tumor cells could ablate into the needle track during radioactive seed implantation.Some preventive measures,such as optimization of pre-operation and intra-operation treatment plan,chemotherapy or endocrine therapy after operation,may be beneficial to avoid the implantation metastasis of neoplasm in seeding needle tracks.
文摘Charge breeding technique is used for RIB （radioactive ion beam） production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1＋ to a desired value n＋. In some experiments, a continuous RIB of a given energy may be required. To reach this goal, a charge breeding device based on a hollow gun EBIS （electron beam ion source） has been proposed by the author recently. That EBIS, in principle, can be capable to realize a CW （continuous wave） operation. A sufficiently high focusing magnetic field could reduce to zero the hole radius in the EBIS electron beam. However, a smaller efficiency in the ion charge state increase should be expected. A code developed for studying the ion selective containment in a EBIS has been modified and used to simulate the ion charge state breeding. The effects of the hollow electron beam on the breeding rate have been studied.
文摘In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.
文摘The objective of this work is to develop an automation system for quality control （QC） in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding （LBW）. These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of lodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller （PLC）, step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices （GMP）. Nowadays, the Radiation Technology Centre at IPEN-CNEN/SP imports and distributes 36,000 lodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 lodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil.
