A localized paediatric intracranial tumour is a representative indication where proton therapy can reduce unnecessary absorbed dose to the developing brain and other normal tissue. The finite particle range can reduce exit and integral dose compared with many photon radiotherapyplans, which may reduce late effects and secondary cancerrisk over a long expected survival. It remains necessary to maintain target coverage, account for changing anatomy and keep uncertain distal-edge relative biological effectiveness away from sensitive structures. Travel, cost and daily positioning are practical disadvantages. The relevant comparison is a robust individual treatment plan and clinical endpoint, rather than the label “proton” alone.[ref]
