2 Brachytherapy Physics-Sources and Dosimetry

Brachytherapy Physics: Sources and Dosimetry

16

THE GEC ESTRO HANDBOOK OF BRACHYTHERAPY | Part I: The basics of Brachytherapy Version 1 - 01/12/2014

Fig. 2.12 Two graphs in one figure for a cesium-137 source model. (i) Dashed line: the radial dose function g(r) according to the TG-43 formalism. (ii) Continuous line: the dose rate as a function of distance from the source, in which the dose gradient is for the largest part determined by the inverse square law. Note that the normalisation of both curves is at 1cm. Data for model CDCS.J was taken from (18). (Courtesy: J. Venselaar)

Fig. 2.14 Components of iridium-192 dose deposition as a function of radial distance for the total dose, the dose due to primary (non-scattered) radiation, and from single and multiple scatter components. See http://www.physics.carleton.ca/clrp/seed_database/Ir192_HDR/microSelec- tron_v2 (7,52).

Fig. 2.13 The radial dose function g(r) according to the TG-43 formalism for the HDR MicroSelectron “classic” iridium-192 source (top left); for an HDR ytterbium-169 source (top right); for four different iodine-125 seed sources (bottom left); and for two palladium-103 seed sources (bottom right). See also the cesium-137 source data in Fig. 2.10. Graphs taken from (3).