Oncology Research Today is a free monthly online journal that collates and summarizes the latest research about Oncology, including details on cancer, surgery, chemotherapy, radiotherapy. | ||||||||
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Calibration of a TLD-100 powder dosimetric system to verify the absorbed dose to water imparted by 137Cs sources in low dose rate brachytherapy at the oncology unit in the Hospital General de Mexico.Alvarez Romero JT, Tovar Muñoz VM, de León BS, Oviedo JO, Barcenas LS, Milo CM, Monterrubio JM SSDL, Metrology Department, ININ, P.O. BOX 18-1027 11801, Mexico City, Mexico. A thermoluminescence dosimetry (TLD) system was characterised at SSDL-ININ to verify the air-kerma strength (S(K)) and dose-to-water (D(W)) values for (137)Cs sources used in low dose rate (LDR) brachytherapy treatments at the Hospital General de Mexico (HGM). It consists of a Harshaw 3500 reader and a set of TLD-100 powder capsules. The samples of TLD-100 powder were calibrated in terms of D(W) vs. nC or nC mg(-1), and their dose response curves were corrected for supralinearity. The D(W) was calculated using the AAPM TG-43 formalism using S(K) for a CDCSM4 (137)Cs reference source. The S(K) value was obtained by using a NE 2611 chamber, and with two well chambers. The angular anisotropy factor was measured with the NE 2611 chamber for this source. The HGM irradiated TLD-100 powder capsules to a reference dose D(W) of 2 Gy with their (137)Cs sources. The percent deviations between the imparted and reference doses were 1.2% </= Delta </= 6.5%, which are consistent with the combined uncertainties: 5.6% </= u(c) </= 9.8% for D(W). Published 21 September 2006 in Radiat Prot Dosimetry, 120(1): 95-9.
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