title: Stereotactic radiation therapy for liver metastases: factors affecting local control and survival.
abstract: OBJECTIVE
  To report on outcome and toxicity of stereotactic body radiotherapy (SBRT) for liver metastases in patients not eligible for surgery.
  
  
  METHODS
  From 2000 to 2009, 74 patients with 91 liver metastases from different primaries have been treated with SBRT at our institution. Median planning target volume was 123 ccm (range: 10.6-1074 ccm). Treatment consisted of 3-5 fractions with 5-12.5 Gy/ fraction prescribed to the surrounding 60-95% isodose with daily image guidance. Regular follow-up included CT or MRI imaging until tumor progression.
  
  
  RESULTS
  Median local recurrence-free interval was 23 months with a local control rate of 74.7%, 48.3% and 48.3% after 1, 2 and 3 years. Only minimum biologically effective dose (BED) to gross tumor volume (GTV) remained as independent significant factor for local control in multivariate analysis. No local recurrences were observed in lesions (n = 12) which received a minimal BED to the GTV of 120 Gy. Including 26 local recurrences, 67 patients (91%) showed disease progression after SBRT with a median time of 5 months. Median overall survival was 27 months with survival rates of 77%, 30% and 27% at 1, 3 and 5 years. On multivariate analysis only GTV volume remained as independent significant prognostic factor for overall survival (p = 0.002). No grade 3 to 5 acute toxicity and no grade 4 or 5 late toxicity occurred.
  
  
  CONCLUSIONS
  SBRT for liver metastases was well tolerated in this non-selected patient cohort and yielded good local control despite the considerable size of most lesions treated. Long-term survival is possible after SBRT.
authors.affiliation: Current Address: Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8006, Zurich, Switzerland. nicolaus.andratschke@usz.ch.|Department of Radiation Oncology, University of Rostock, Rostock, Germany. nicolaus.andratschke@usz.ch.|Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. nicolaus.andratschke@usz.ch.
authors.forename: Nicolaus Hj
authors.initials: NH
authors.lastname: Andratschke
authors.affiliation: Department of Oncology and Palliative Medicine, Nordland Hospital, Bodø, Norway. cnied@hotmail.com.|Institute of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway. cnied@hotmail.com.
authors.forename: Carsten
authors.initials: C
authors.lastname: Nieder
authors.affiliation: Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. fheppt@web.de.|Department of Dermatology, University Hospital Erlangen, Erlangen, Germany. fheppt@web.de.
authors.forename: Franz
authors.initials: F
authors.lastname: Heppt
authors.affiliation: Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. mjmmolls@googlemail.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Molls
authors.affiliation: Institut für Radioonkologie, Medizinische Radiologie, Universitätsspital Basel, Basel, Switzerland. frank.zimmermann@usb.ch.
authors.forename: Frank
authors.initials: F
authors.lastname: Zimmermann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011379:Prognosis; D016634:Radiosurgery / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed