title: [Clinical experience of carbon ion radiotherapy for malignant tumors].
abstract: The carbon ion (C-ion) beams provide unique advantageous biological and physical properties in radiotherapy (RT) for malignant tumors. C-ion beams have a high relative biological effectiveness (RBE) resulting from the high linear energy transfer (LET). In terms of their physical characteristics, C-ion beams exhibit a spread-out Bragg peak (SOBP) and make for a better dose distribution of the target volume by specified beam modulations. Between June 1994 and August 2005, a total of 2,371 patients with malignant tumors were registered in phase I/II dose-escalation studies and clinical phase II trials using C-ion beams generated at Heavy Ion Medical Accelerator in Chiba (HIMAC). In the initial dose-escalation studies, grade 3 or more late rectal complications had developed in some patients. However, the adverse effects were resolved because of the use of appropriate dose levels and modification of the radiation technique. C-ion beams can carry out hypofractionated radiotherapy with a large fraction dose and reduce the overall treatment times compared with conventional radiotherapy. They can also achieve better local tumor control even for radio-resistant tumors such as malignant melanoma, hepatocellular carcinoma and bone and soft tissue sarcomas with minimal morbidity to the normal surrounding tissues.
authors.affiliation: Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS).
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tsujii
mesh_terms: D001859:Bone Neoplasms / Q000532:radiotherapy; D002244:Carbon / Q000627:therapeutic use*; D017321:Clinical Trials, Phase I as Topic; D017322:Clinical Trials, Phase II as Topic; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D063193:Heavy Ion Radiotherapy; D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy; D008175:Lung Neoplasms / Q000532:radiotherapy; D008297:Male; D009369:Neoplasms / Q000532:radiotherapy*; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D012062:Relative Biological Effectiveness
chemical_list: D002244:Carbon