title: [Proton therapy on locally advanced cancer].
abstract: Conventionally, radiation considerably affects normal cells on the body's surface before it reaches the focal lesion; it is reduced and weakened at the focal lesion, and unable to fully demonstrate the potential effectiveness of radiotherapy. The radiation level in proton beam (particle beam) therapy characteristically reaches a peak (a Bragg peak) at a particular depth. Radiation can be concentrated on only the focal lesion while keeping damage to normal cells low, because cancer is irradiated by matching the peak position to the focal cancer. When a proton beam is blasted inside the body, the radiation reaches the cancer cells, yet normal cells are hardly affected. The blast reaches the DNA inside the nucleus of cancer cells. When the proton beam hits the DNA, the DNAs of cancer cells are damaged directly or indirectly. When this occurs, the probability is high that both double helixes of the DNA will be damaged, and significant effectiveness can be expected from the proton beam, with respect to cancer cells that may return with traditional radiation. Proton therapy effectiveness is confirmed for prostate cancer, liver cancer, lung cancer, head and neck cancer (including sinus cancer), and eye tumor (including uveal melanoma). All of these conditions have been difficult to treat with traditional radiation and surgery.
authors.affiliation: Southern Tohoku Proton Therapy Center.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Fuwa
mesh_terms: D005544:Forecasting; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy*; D061766:Proton Therapy; D011878:Radiotherapy / Q000639:trends; D011522:Protons
chemical_list: D011522:Protons