Morphological Adaptive Radiation Therapy: The impact of weekly anatomical changes

The treatment of mucosal Head and Neck (H+N) cancers with radiotherapy has seen considerable technological development over recent years; from large non-conformal fields, to three- Dimensional Conformal Radiation Therapy (3-D CRT) and subsequently the introduction of Intensity Modulated Radiation Therapy (IMRT), Volumetric Modulated Arc Therapy (VMAT) and other radiation therapy delivery techniques, such as proton therapy. When compared to older "conventional" techniques, the IMRT planning process results in improved dose to tumour volumes, whilst simultaneously reducing Organ at Risk (OAR) dose; i.e. an improvement of the therapeutic index. This dosimetric improvement translates into clinical benefits; especially in terms of reduced radiotherapy toxicity and Quality of Life.