Dosimetric Characteristics for Brachytherapy Sources Available to Purchase

Brachytherapy sources are characterized by the dosimetric parameters in a protocol such as the American Association of Physicists in Medicine Task Group 43. The air‐kerma strength is measured and traceable to a primary standard. Then the parameters such as dose‐rate constant, radial dose function, and anisotropy function are measured and related back to the primary standard. This is normally accomplished with thermoluminescent dosimeters (TLDs). Since radial dose function and anisotropy function are relative parameters, some of the dosimetric corrections are negligible. For the dose‐rate constant, parameters such as the energy dependence compared with a calibration beam such as $60Co$ need to be accounted for. A description of the primary standard measurements and TLD measurements will be discussed.