Leakage test evaluation used for qualification of iodine-125 seeds sealing

• Autorzy: Feher A. , Rostelato M. E. C. M. , Zeituni C. A. , Calvo W. A. P. , Somessari S. L. , Moura J. A. , Moura E. S. , Souza C. D. , Rela P. R.
• Języki publikacji: EN

Abstrakty

EN

Brachytherapy is one of the possible treatments with ionizing radiation available for prostate cancer, in which small seeds containing iodine-125 radioisotope are implanted directly into the prostate. The seed consists of a sealed titanium tube containing a central silver wire with adsorbed iodine-125. The tube sealing is made with titanium at the ends, using plasma arc-welding (PAW) or laser process. This sealing must be leakage-resistant and free of cracks, therefore avoiding iodine-125 to deposit in the silver wire to escape and spread into the human body. To ensure that this problem is not occurring, rigorous leakage tests in accordance with the standard ISO-9978 should be applied. The aim of this study is to determine, implement and evaluate the leakage test to be used in the iodine-125 seeds production, in order to qualify the sealing procedure. The standard ISO-9978 presents a list of tests to be carried out according to the type of source. The preferential methods for brachytherapy sources are soaking and helium. To assess the seeds leakage, the method of immersion test at room temperature was applied. The seeds are considered leakage-free if the detected activity does not exceed 185 Bq (5 nCi). An iodine standard was prepared and its value determined in a sodium iodide detector. A liquid scintillation counter was calibrated with the standard for seed leakage tests. Forty-eight seeds were plasma arc-welded for these tests.

Słowa kluczowe

EN

leakage test; iodine-125 seeds; prostate cancer; brachytherapy; titanium tube; standard ISO-9978

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2011
• Tom: Vol. 56, No. 4
• Strony: 375--379
• Opis fizyczny: Bibliogr. 11 poz., rys.

Twórcy

autor

Feher A.

autor

Rostelato M. E. C. M.

autor

Zeituni C. A.

autor

Calvo W. A. P.

autor

Somessari S. L.

autor

Moura J. A.

autor

Moura E. S.

autor

Souza C. D.

autor

Rela P. R.

• National Nuclear Energy Commission (CNEN/SP), Institute for Nuclear and Energy Research (IPEN), Radiation Technology Center (CTR), 2242 Prof. Lineu Prestes Ave., – Cidade Universitaria, 05508-000, Săo Paulo – SP, Brazil, Tel.: + 55 11 3133 9762/9795,

Bibliografia

• 1. Blasko JC, Grimm PD, Rade H (1993) Brachytherapy and organ preservation in the management of carcinoma of the prostate. Semin Rad Oncol 3;4:240–249
• 2. Butler WM (2000) Review of modern prostate brachytherapy. In: Proc of the World Congress on Medical Physics and Biomedical Engineering, 23–28 July 2000, Chicago
• 3. Feler A (2006) Development of plasma arc welding process for iodine-125 seed production. Master of science degree, Institute for Nuclear and Energy Research (IPEN), São Paulo, Brazil
• 4. Gray JR (1998) Prostate brachytherapy: a new treatment option for prostate cancer patients. HCA Healthcare Corp, Columbia. https://www.medtropolis.com/healthcontents. asp?page=”/htc/prostate/CRS/index, accessed 4 July 2009
• 5. ISO (1992) ISO-9978: Radiation protection – sealed radioactive sources – leakage test methods. International Standard Organization
• 6. Meigooni AS (2000) Dosimetric characterization of low energy brachytherapy sources: measurements. In: Proc of the World Congress on Medical Physics and Biomedical Engineering, 23–28 July 2000, Chicago
• 7. Meigooni AS, Gearheart DM, Sowards K (2000) Experimental determination of dosimetric characteristics of best I-125 brachytherapy source. Med Phys 27;9:2168–2173
• 8. Pollack A, Zagars GK, Rosen II (1999) Prostate cancer treatment with radiotherapy: maturing methods that minimize morbidity. Semin Oncol MD, Anderson Cancer Center 26;2:150–161
• 9. Rostelato MECM, Rela PR, Gasiglia HT, Lepki V, Feher A (2000) Iodine-125 seeds production for brachytherapy use. In: Proc of the World Congress on Medical Physics and Biomedical Engineering, 23–28 July, 2000, Chicago
• 10. Rostelato MECM (2005) Study and development of a new methodology for iodine-125 brachytherapy seed production. PhD degree, Institute for Nuclear and Energy Research (IPEN), São Paulo, Brazil
• 11.Strum SB, Schulz MC (1996) Brachytherapy: implantation of prostate cancer with radioactive isotope – analysis of the Seattle experimence: May 1996 update. http://www.prostatepointers.org/seadpods/brachy07.htm/, accessed 4 July 2009