title: Stereotactic body radiotherapy (SBRT) for medically inoperable lung metastases-A pooled analysis of the German working group "stereotactic radiotherapy".
abstract: The current literature on stereotactic body radiotherapy (SBRT) for oligometastatic disease is characterized by small patient cohorts with heterogeneous primary tumors, metastases location and dose regimes. Hence, this study established a multi-institutional database of 700 patients treated with SBRT for pulmonary metastases to identify prognostic factors influencing survival and local control.
  
  
  
  All German radiotherapy departments were contacted and invited to participate in this analysis. A total number of 700 patients with medically inoperable lung metastases treated with SBRT in 20 centers between 1997 and 2014 were included in a database. Primary and metastatic tumor characteristics, treatment characteristics and follow-up data including survival, local control, distant metastases, and toxicity were evaluated. Lung metastases were treated with median PTV-encompassing single doses of 12.5Gy (range 3.0-33.0Gy) in a median number of 3 fractions (range 1-13).
  
  
  
  After a median follow-up time of 14.3 months, 2-year local control (LC) and overall survival (OS) were 81.2% and 54.4%, respectively. In multivariate analysis, OS was most significantly influenced by pretreatment performance status, maximum metastasis diameter, primary tumor histology, time interval between primary tumor diagnosis and SBRT treatment and number of metastases. For LC, independent prognostic factors were pretreatment performance status, biological effective dose (BED) at PTV isocenter (BEDISO) and single fraction (PTV-encompassing) dose in multivariate analysis. Radiation-induced pneumonitis grade 2 or higher was observed in 6.5% of patients. The only factor significantly influencing toxicity was BEDISO (p=0.006).
  
  
  
  SBRT for medically inoperable patients with pulmonary metastases achieved excellent local control and promising overall survival. Important prognostic factors were identified for selecting patients who might benefit most from this therapy approach.
authors.affiliation: Department of Radiation Oncology, University Hospital Heidelberg, Germany; Heidelberg Institute of Radiation Oncology, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Rieber
authors.affiliation: Department of Radiation Oncology, University Hospital Heidelberg, Germany; Heidelberg Institute of Radiation Oncology, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Streblow
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Uhlmann
authors.affiliation: Department of Radiation Oncology, University Hospital Wuerzburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Flentje
authors.affiliation: Department of Radiation Oncology, Technical University Munich, Germany.
authors.forename: Marciana
authors.initials: M
authors.lastname: Duma
authors.affiliation: Department of Radiation Oncology, University Hospital Münster, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Ernst
authors.affiliation: Department of Radiation Oncology, UKSH Universitätsklinikum Schleswig-Holstein, Kiel, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Blanck
authors.affiliation: Department of Radiotherapy and Radiation Oncology, Philipps-University Marburg, University Hospital Giessen and Marburg, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Wittig
authors.affiliation: Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany.
authors.forename: Judit
authors.initials: J
authors.lastname: Boda-Heggemann
authors.affiliation: Department of Radiation Oncology, Helios Klinikum Berlin Buch, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Krempien
authors.affiliation: Department of Radiation Oncology, Medical Faculty and University Hospital C.G. Carus, Technical University Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg and German Cancer Consortium (DKTK) partner site Dresden, Germany; OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Lohaus
authors.affiliation: Department of Radiation Oncology, Bern University Hospital, Bern, Switzerland.
authors.forename: Nathalie Desirée
authors.initials: ND
authors.lastname: Klass
authors.affiliation: Department of Radiation Oncology, University Hospital Aachen, Germany.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Eble
authors.affiliation: Department of Radiation Oncology, University Hospital Frankfurt, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Imhoff
authors.affiliation: Department of Radiation Oncology, Hospital Augsburg, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Kahl
authors.affiliation: Department of Radiation Oncology, University Hospital Hamburg, Germany.
authors.forename: Cordula
authors.initials: C
authors.lastname: Petersen
authors.affiliation: Department of Radiation Oncology, Ludwig Maximilians University Munich, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Gerum
authors.affiliation: Department of Radiotherapy and Special Oncology, Medical School Hannover, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Henkenberens
authors.affiliation: Department of Radiation Oncology, University Hospital Freiburg, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Adebahr
authors.affiliation: Department of Radiation Oncology, University Hospital Magdeburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hass
authors.affiliation: Department of Radiation Oncology, Hospital Heidenheim, Germany.
authors.forename: Elsge
authors.initials: E
authors.lastname: Schrade
authors.affiliation: Department of Radiation Oncology, University Hospital Jena, Germany.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Wendt
authors.affiliation: Department of Radiation Oncology, University of Rostock, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Hildebrandt
authors.affiliation: Department of Radiation Oncology, University of Rostock, Germany; Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: Nicolaus
authors.initials: N
authors.lastname: Andratschke
authors.affiliation: Department of Radiation Oncology, University Hospital Heidelberg, Germany; Heidelberg Institute of Radiation Oncology, Germany; German Cancer Research Center, Clinical Cooperation Unit Radiation Oncology, Heidelberg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Sterzing
authors.affiliation: Department of Radiation Oncology, University Hospital Wuerzburg, Germany; Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Switzerland. Electronic address: juliane.rieber@med.uni-heidelberg.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Guckenberger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D006801:Humans; D017567:Karnofsky Performance Status; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D000072078:Positron Emission Tomography Computed Tomography; D011379:Prognosis; D017564:Radiation Pneumonitis / Q000150:complications / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods* / Q000401:mortality; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Extracranial stereotactic radiotherapy; Lung metastases; Oligometastases; Pulmonary SBRT; Radiosurgery; Stereotactic body radiotherapy (SBRT)