Anne Li August 6th, 2017
A tumour is a 3D ball of cells, each with a unique shape and position in the body. This causes a problem for radiotherapy as some parts of the tumour may be closer to healthy tissues than others. The stronger the radiotherapy beam the more damage it will do to normal cells, which increases side effects and the chance of scarring. So radiotherapists have borrowed a trick from the theater. Just as leading actors get a strong spotlight on stage with the rest of the set lit less brightly, different parts of a tumour can get different intensities of radiotherapy.
See original article at: http://scienceblog.cancerresearchuk.org/2017/07/31/imrt-bending-radiotherapy-beams-to-spare-healthy-cells/