"Proton therapy is an advanced form of radiotherapy which has the potential to deliver a dose map that closely matches the tumour volume.The current state of the art in proton therapy utilises a technique called spot-scanning which uses a narrow beam of protons guided by a pair of magnetic fields to paint a dose ""picture"" over the tumour. The goal of this project is to resolve some of the as yet unanswered questions surrounding quality assurance in spot-scanned proton therapy.This project will employ Monte Carlo simulation and experimental methods to determine correction factors for dosimetry in spot scanning proton therapy beams. The project will further explore the dosimetric issues associated with the edge effects of a small proton beam and also perform a preliminary investigation of the relation with biological dosimetry of protons. The outcome will be a set of factors that enable greater dose accuracy and a detailed understanding of the dosimetry of small field proton beams, which can inform an international code of practice.The outgoing host for the project will be the Massachusetts General Hospital Proton Therapy Centre, and the return host will be University College London, who are currently building a spot scanning proton therapy clinic. Collaborators from IBA Particle Therapy, the UK Institute of Cancer Research and the UK National Physical Laboratory will also be involved.The applicant will be trained in proton therapy dosimetry research techniques, as well as receive clinical training in proton therapy treatment QA and delivery."