title: Stereotactic body radiotherapy for centrally located early-stage non-small cell lung cancer or lung metastases from the RSSearch(®) patient registry.
abstract: BACKGROUND
  The purpose of this study was to evaluate treatment patterns and outcomes of stereotactic body radiotherapy (SBRT) for centrally located primary non-small cell lung cancer (NSCLC) or lung metastases from the RSSearch(®) Patient Registry, an international, multi-center patient registry dedicated to radiosurgery and SBRT.
  
  
  METHODS
  Eligible patients included those with centrally located lung tumors clinically staged T1-T2 N0, M0, biopsy-confirmed NSCLC or lung metastases treated with SBRT between November 2004 and January 2014. Descriptive analysis was used to report patient demographics and treatment patterns. Overall survival (OS) and local control (LC) were determined using Kaplan-Meier method. Toxicity was reported using the Common Terminology Criteria for Adverse Events version 3.0.
  
  
  RESULTS
  In total, 111 patients with 114 centrally located lung tumors (48 T1-T2,N0,M0 NSCLC and 66 lung metastases) were treated with SBRT at 19 academic and community-based radiotherapy centers in the US and Germany. Median follow-up was 17 months (range, 1-72). Median age was 74 years for primary NSCLC patients and 65 years for lung metastases patients (p < 0.001). SBRT dose varied from 16 - 60 Gy (median 48 Gy) delivered in 1-5 fractions (median 4 fractions). Median dose to centrally located primary NSCLC was 48 Gy compared to 37.5 Gy for lung metastases (p = 0.0001) and median BED10 was 105.6 Gy for primary NSCLC and 93.6 Gy for lung metastases (p = 0.0005). Two-year OS for T1N0M0 and T2N0M0 NSCLC was 79 and 32.1 %, respectively (p = 0.009) and 2-year OS for lung metastases was 49.6 %. Two-year LC was 76.4 and 69.8 % for primary NSCLC and lung metastases, respectively. Toxicity was low with no Grade 3 or higher acute or late toxicities.
  
  
  CONCLUSIONS
  Overall, patients with centrally located primary NSCLC were older and received higher doses of SBRT than those with lung metastases. Despite these differences, LC and OS was favorable for patients with central lung tumors treated with SBRT. Reported toxicity was low, although low grade toxicities were observed in patients where dose tolerances approached or exceeded published guidelines. Prospective studies are needed to further define the optimal SBRT dose for this cohort of patients.
  
  
  BACKGROUND
  Clinicaltrials.gov Identifier: NCT01885299.
authors.affiliation: The Radiosurgery Society®, 1350 Dell, Suite 105, Campbell, CA, 95008, USA. jdavis@therss.org.
authors.forename: Joanne N
authors.initials: JN
authors.lastname: Davis
authors.affiliation: Department of Radiation Oncology, St. Anthony Hospital, Oklahoma City, OK, USA. buddy@swrads.org.
authors.forename: Clinton
authors.initials: C
authors.lastname: Medbery
authors.affiliation: Department of Radiation Oncology, St. Mary's Medical Center, Huntington, WV, USA. sharmalahr@comcast.net.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Radiation Oncology, St. Joseph/Candler Hospital, Savannah, GA, USA. drpablo@sjchs.org.
authors.forename: John
authors.initials: J
authors.lastname: Pablo
authors.affiliation: Department of Radiation Oncology, Erlanger Health System, Chattanooga, TN, USA. fckimsey@gmail.com.
authors.forename: Frank
authors.initials: F
authors.lastname: Kimsey
authors.affiliation: Department of Radiation Oncology, Medstar Franklin Square Medical Center, Baltimore, MD, USA. David.James.Perry@medstar.net.
authors.forename: David
authors.initials: D
authors.lastname: Perry
authors.affiliation: European CyberKnife Center Munich-Grosshadern and Munich University, Munich, Germany. Alexander.Muacevic@Cyber-Knife.net.
authors.forename: Alexander
authors.initials: A
authors.lastname: Muacevic
authors.affiliation: Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. amahadev@bidmc.harvard.edu.
authors.forename: Anand
authors.initials: A
authors.lastname: Mahadevan
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D011379:Prognosis; D016634:Radiosurgery / Q000401:mortality*; D011879:Radiotherapy Dosage; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate