Advanced Physics for Brachytherapy 2018

TLD: sensitivity/linearity

• TLD is effective in terms of interacting with photons in the brachytherapy E range • The TL mechanism however is inefficient • About 0.04% of TLD absorbed dose is emitted as TL energy per unit mass • Individual TLD calibration is required as well as meticulous care in reproducible conditions of use to ensure precision/accuracy • TLD dynamic dose range is wide. It comprises a linear D region followed by a region of supra- linearity and, eventually, saturation • Linearity cannot be assumed and has to be measured by irradiating TLD groups in graded doses in the region of interest

Table from: Mayles, Nahum, Rosenwald (Eds): Handbook of radiotherapy physics: theory and practice,© 2007 by Taylor & Francis Group LLC