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A comparison of solid phantoms with water for dosimetry of 1 2 5 I brachytherapy sources
Author(s) -
Meigooni Ali S.,
Meli Jerome A.,
Nath Ravinder
Publication year - 1988
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 - 10.1118/1.596182
Subject(s) - dosimetry , imaging phantom , monte carlo method , photon , polystyrene , brachytherapy , materials science , thermoluminescence , thermoluminescent dosimetry , photon energy , thermoluminescent dosimeter , nuclear medicine , physics , optics , nuclear physics , irradiation , dosimeter , nuclear magnetic resonance , radiation therapy , medicine , mathematics , statistics , polymer
Dosimetry of brachytherapy sources is critically dependent on precise measurement of the source–detector distance. A solid phantom can be precisely machined and hence distances can be accurately determined. In this work LiF thermoluminescent chips are used for absolute dose rate measurements in solid water, polymethylmethacrylate (PMMA), and polystyrene. These media are examined for their suitability in the dosimetry of 1 2 5 I by comparing depth doses in each phantom. Measurements and Monte Carlo calculations show that solid water is equivalent to water for the dosimetry of 1 2 5 I seeds, however, polystyrene and PMMA are not equivalent to water. Also, photon energy spectra for several depths in each phantom material have been calculated and are used to determine average photon energy and mass energy absorption coefficients as a function of depth.