Implementation of Image-Guidance Techniques in Radiation Therapy

For more than 100 years, physicists have been a vital part of the medical team required to deliver radiation therapy. Their role encompasses the verification of dose accuracy to the development and implementation of new techniques, the most recent of which is the incorporation of daily image guidance to account for inter- and intra-fraction target changes. For example, computed tomography (CT) integrated into radiotherapy treatment units allows the image-guided treatment of the prostate where the target location depends on the degree of rectal filling a parameter that changes on timescales from minutes to weeks. Different technology is required for the adequate treatment of small lung tumours since respiration occurs on timescales of seconds. This presentation will review current image-guided techniques.