title: Proton beam therapy for metastatic liver tumors.
abstract: OBJECTIVE
  The purpose of this study was to investigate the safety and efficacy of proton beam therapy (PBT) for the treatment of metastatic liver tumors.
  
  
  METHODS
  A total of 140 patients with liver metastasis who received PBT were retrospectively investigated. The main primary tumor sites were the colorectum (60) and the pancreas (19).
  
  
  RESULTS
  One hundred thirty-three patients (95%) completed treatment. Two patients experienced late adverse effects (rib fracture and cholangitis). The 5-year overall survival (OS) rate was 24%. In the 85 patients with lesions confined to the liver, the 5-year OS rate of was 28%, and in the 55 patients with lesions both inside and outside the liver, it was 16% (P=0.007). Among the patients with lesions confined to the liver, the 5-year OS rate of the 62 patients who received curative treatment was 30%, and that of the 23 patients who received palliative treatment, 23% (P=0.016). Multivariate analysis showed that the treatment strategy (curative and palliative) alone was associated with the OS rate (P=0.02).
  
  
  CONCLUSIONS
  PBT is a potentially safe and effective treatment for metastatic liver tumors.
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan. Electronic address: fukumitsun@yahoo.co.jp.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Fukumitsu
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okumura
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Takizawa
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Makishima
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Haruko
authors.initials: H
authors.lastname: Numajiri
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Murofushi
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Ohnishi
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizumoto
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Teruhito
authors.initials: T
authors.lastname: Aihara
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuboi
authors.affiliation: Proton Medical Research Center, University of Tsukuba, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Sakurai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology*; D061766:Proton Therapy / Q000379:methods*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
keywords: Metastatic liver tumor; Proton beam therapy; Survival rate