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Thermoluminescent dosimetry for 1 0 3 Pd seeds (model 200) in solid water phantom
Author(s) -
ChiuTsao SouTung,
Anderson Lowell L.
Publication year - 1991
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.596692
Subject(s) - thermoluminescent dosimeter , imaging phantom , dosimeter , dosimetry , physics , transverse plane , nuclear medicine , materials science , radiation , optics , medicine , structural engineering , engineering
Dose measurements using LiF thermoluminescent dosimeters (TLD) have been performed for single 1 0 3 Pd seeds (model 200) at the center of a solid water phantom. TLD cubes 1 mm on an edge were used for measurements from 1 mm to 1 cm at 1‐mm intervals. The cubes were centered along transverse and longitudinal axes and along radial lines from seed center at 10° increments. TLD chips of dimension 3.1×3.1×0.89 mm were used at distances of 2, 2.5, 3, and 4 cm at l5° angular intervals. Data are presented as the product of distance squared and dose rate per unit source strength, plotted versus distance and angle. At 1 cm from seed center along the transverse axis this product was found to be 0.88 cGy cm 2 mCi − 1 h − 1 . A dose‐rate table in polar coordinates has been formulated for use with multiseed dose distribution calculations. Comparison with data of Meigooni e t a l . [Endocuriether./Hyperthermia Oncol. 6 , 107–117 (1990)] shows general agreement for distances of 2 cm or greater. A comparison of our transverse axis data with Russell's calculated values (Theragenics Internal Report, 4 November 1984) for an ideal point source of 1 0 3 Pd shows very good agreement except at distances less than 0.5 cm, where differences are attributable to the extended source effect in the actual seed.