Advanced Physics for Brachytherapy 2018

Source-Detector Distance “problem” 1. Displacement of the dosimeter relative to plan position a) Organ-induced displacement b) Manipulation error (digitization, displacement before measurements…) 2. Displacement of source position(s) relative to plan position(s) a) Displacement of one or more catheters or an applicator, including rotation for certain applicators. b) Organ-induced displacement c) Manipulation error (wrong transfer tube connection…) 3. Combination of the above two i.e. source and sensor displacements a) Perfectly in sync: no effect on dose measured but effect on dose delivered b) Out of sync 4. Organ-related change that does not impact the relative distances but organ dosimetry (e.g. swelling, deformation, …)