title: Dose-escalation study of single-fraction stereotactic body radiotherapy for liver malignancies.
abstract: OBJECTIVE
  We performed a Phase I dose-escalation study to explore the feasibility and safety of treating primary and metastatic liver tumors with single-fraction stereotactic body radiotherapy (SBRT).
  
  
  METHODS
  Between February 2004 and February 2008, 26 patients were treated for 40 identifiable lesions. Nineteen patients had hepatic metastases, 5 had intrahepatic cholangiocarcinomas, and 2 had recurrent hepatocellular carcinomas. The prescribed radiation dose was escalated from 18 to 30 Gy at 4-Gy increments with a planned maximum dose of 30 Gy. Cumulative incidence functions accounted for competing risks to estimate local failure (LF) incidence over time under the competing risk of death.
  
  
  RESULTS
  All patients tolerated the single-fraction SBRT well without developing a dose-limiting toxicity. Nine acute Grade 1 toxicities, one acute Grade 2 toxicity, and two late Grade 2 gastrointestinal toxicities were observed. After a median of 17 months follow-up (range, 2-55 months), the cumulative risk of LF at 12 months was 23%. Fifteen patients have died: 11 treated for liver metastases and 4 with primary liver tumors died. The median survival was 28.6 months, and the 2-year actuarial overall survival was 50.4%.
  
  
  CONCLUSIONS
  It is feasible and safe to deliver single-fraction, high-dose SBRT to primary or metastatic liver malignancies measuring ≤5 cm. Moreover, single-fraction SBRT for liver lesions demonstrated promising local tumor control with minimal acute and long-term toxicity. Single-fraction SBRT appears to be a viable nonsurgical option, but further studies are warranted to evaluate both control rates and impact on quality of life.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. goodmank@mskcc.org
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Wiegner
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Maturen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Qianxing
authors.initials: Q
authors.lastname: Mo
authors.forename: George
authors.initials: G
authors.lastname: Yang
authors.forename: Iris C
authors.initials: IC
authors.lastname: Gibbs
authors.forename: George A
authors.initials: GA
authors.lastname: Fisher
authors.forename: Albert C
authors.initials: AC
authors.lastname: Koong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000601:surgery*; D001653:Bile Ducts, Intrahepatic; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D018281:Cholangiocarcinoma / Q000601:surgery*; D004381:Duodenal Ulcer / Q000209:etiology; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery; D011832:Radiation Injuries / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D017211:Treatment Failure; D047368:Tumor Burden; D055815:Young Adult