关键词：放射治疗,质子束流;辐射剂量;癌症;临床医学;医疗;肿瘤;治疗;医疗保险
摘 要：Proton beam radiotherapy is a form of external beam radiation that offers better precision for localized dosage than other types of external beam radiotherapy. Because proton beams deposit most of their energy during the final portion of their trajectory, they diminish the risk of damage to tissue surrounding the tumor and thus allow for higher treatment doses with fewer side effects. Proton beam radiotherapy has been used in research applications since the 1950s and entered clinical practice in the United States in 1990. No randomized controlled trials and only a few well-conducted cohort studies have compared proton beam radiation to other treatments. In the absence of evidence of clinical superiority, proton beam radiotherapy has gained acceptance based on a theoretical advantage for the treatment of specific cancers.