دورية أكاديمية
Monte Carlo calculations of the ionization chamber wall correction factors for 192Ir and 60Co gamma rays and 250 kV x-rays for use in calibration of 192Ir HDR brachytherapy sources.
| العنوان: | Monte Carlo calculations of the ionization chamber wall correction factors for 192Ir and 60Co gamma rays and 250 kV x-rays for use in calibration of 192Ir HDR brachytherapy sources. |
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| المؤلفون: | Ferreira IH; Service de Physique, Institut Gustave-Roussy, Villejuif, France. thesards@igr.fr, de Almeida CE, Marre D, Marechal MH, Bridier A, Chavaudra J |
| المصدر: | Physics in medicine and biology [Phys Med Biol] 1999 Aug; Vol. 44 (8), pp. 1897-904. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: IOP Publishing Country of Publication: England NLM ID: 0401220 Publication Model: Print Cited Medium: Print ISSN: 0031-9155 (Print) Linking ISSN: 00319155 NLM ISO Abbreviation: Phys Med Biol Subsets: MEDLINE |
| أسماء مطبوعة: | Original Publication: Bristol : IOP Publishing |
| مواضيع طبية MeSH: | Gamma Rays* , Monte Carlo Method*, Brachytherapy/*methods , Cobalt Radioisotopes/*analysis , Iridium Radioisotopes/*analysis, Calibration ; Computer Simulation ; Dose-Response Relationship, Radiation ; Models, Theoretical ; Radiotherapy Dosage ; User-Computer Interface ; X-Rays |
| مستخلص: | As in the method for the calibration of 192Ir high-dose-rate (HDR) brachytherapy sources, the ionization chamber wall correction factor A(w), is needed for 192Ir and 60Co gamma rays and 250 kV x-rays. This factor takes into account the variation in chamber response due to the attenuation of the photon beam in the chamber wall and build-up cap and the contribution of scattered photons. Monte Carlo calculations were performed using the EGS4 code system with the PRESTA algorithm, to calculate the A(w) factor for 51 commercial ionization chambers and build-up caps exposed to the typical energy spectrum of 192Ir and 60Co gamma rays and 250 kV x-rays. The calculated A(w) correction factors for 192Ir and 60Co sources and 250 kV x-rays agree very well to within 0.1% with published experimental data (the statistical uncertainty is less than 0.1% of the calculated correction factor value). For the 192Ir sources, A(w) varies from 0.973 to 0.993 and for the 250 kV x-rays the minimum value of A(w) for all chambers studied is 0.983. The calculated A(w) correction factors can be used to calculate the air kerma calibration factor of HDR brachytherapy sources, when interpolative methods are considered, contributing to the reduction in the overall uncertainties in the calibration procedure. |
| المشرفين على المادة: | 0 (Cobalt Radioisotopes) 0 (Iridium Radioisotopes) |
| تواريخ الأحداث: | Date Created: 19990903 Date Completed: 19991013 Latest Revision: 20190726 |
| رمز التحديث: | 20240628 |
| DOI: | 10.1088/0031-9155/44/8/304 |
| PMID: | 10473203 |
| قاعدة البيانات: | MEDLINE |
| تدمد: | 0031-9155 |
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| DOI: | 10.1088/0031-9155/44/8/304 |