title: Lung metastases treated with stereotactic body radiotherapy: the RSSearch® patient Registry's experience.
abstract: OBJECTIVE
  To report overall survival and local control for patients identified in the RSSearch® Patient Registry with metastatic cancer to the lung treated with SBRT.
  
  
  METHODS
  Seven hundred two patients were identified with lung metastases in the RSSearch® Registry. Of these patients, 577 patients had SBRT dose and fractionation information available. Patients were excluded if they received prior surgery, radiation, or radiofrequency ablation to the SBRT treated area. Between April 2004-July 2015, 447 patients treated with SBRT at 30 academic and community-based centers were evaluable for overall survival (OS). Three hundred four patients with 327 lesions were evaluable for local control (LC). All doses were converted to Monte Carlo equivalents and subsequent BED Gy10for dose response analysis.
  
  
  RESULTS
  Median age was 69 years (range, 18-93 years). Median Karnofsky performance status (KPS) was 90 (range 25/75% 80-100). 49.2% of patients had prior systemic therapy. Median metastasis volume was 10.58 cc (range 25/75% 3.7-25.54 cc). Site of primary tumor included colorectal (25.7%), lung (16.6%), head and neck (11.4%), breast (9.2%), kidney (8.1%), skin (6.5%) and other (22.1%). Median dose was 50 Gy (range 25/75% 48-54) delivered in 3 fractions (range 25/75% 3-5) with a median BED of 100Gy10(range 25/75% 81-136). Median OS for the entire group was 26 months, with actuarial 1-, 3-, and 5-year OS of 74.1%, 33.3, and 21.8%, respectively. Patients with head and neck and breast cancers had longer median OS of 37 and 32 months respectively, compared to colorectal (30 months) and lung (26 months) which corresponded to 3-year actuarial OS of 51.8 and 47.9% for head and neck and breast respectively, compared to 35.8% for colorectal and 31.2% for lung. The median LC for all patients was 53 months, with actuarial 1-, 3-, and 5-year LC rates of 80.4, 58.9, and 46.3%, respectively. There was no difference in LC by primary histologic type (p = 0.49). Improved LC was observed for lung metastases that received SBRT doses of BED ≥100Gy10with 3-year LC rate of 77.1% compared to 45% for lung metastases treated with BED < 100Gy10(p = 0.01). Smaller tumor volumes (<11 cc) had improved LC compared to tumor volumes > 11 cc. (p = 0.005) Two-year LC rates for tumor volumes < 11 cc, 11-27 cc and > 27 cc were 72.9, 64.2 and 45.6%, respectively. This correlated with improved OS with 2-year OS rates of 62.4, 60.9 and 46.2% for tumor volumes < 11 cc, 11-27 cc and > 27 cc, respectively (p = 0.0023). In a subset of patients who received BED ≥100Gy10, 2-year LC rates for tumor volumes < 11 cc, 11-27 cc and > 27 cc were 82.8, 58.9 and 68.6%, respectively (p = 0.0244), and 2-year OS rates were 66.0, 58.8 and 28.5%, respectively (p = 0.0081).
  
  
  CONCLUSIONS
  Excellent OS and LC is achievable with SBRT utilizing BED ≥100Gy10for lung metastases according to the RSSearch® Registry data. Patients with small lung metastases (volumes < 11 cc) had better LC and OS when using SBRT doses of BED ≥100Gy10. Further studies to evaluate a difference, if any, between various tumor types will require a larger number of patients.
authors.affiliation: Crozer-Keystone Health System, Philadelphia CyberKnife, Havertown, PA, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Ricco
authors.affiliation: The Radiosurgical Society, Sunnyvale, CA, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: Davis
authors.affiliation: Crozer-Keystone Health System, Philadelphia CyberKnife, Havertown, PA, USA.
authors.forename: William
authors.initials: W
authors.lastname: Rate
authors.affiliation: Crozer-Keystone Health System, Philadelphia CyberKnife, Havertown, PA, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: MedStar Franklin Square Medical Center, Baltimore, MD, USA.
authors.forename: David
authors.initials: D
authors.lastname: Perry
authors.affiliation: St. Joseph's/Chandler Savannah Hospital, Savannah, GA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Pablo
authors.affiliation: East Coast Radiation Oncology Associates, Toms River, NJ, USA.
authors.forename: David
authors.initials: D
authors.lastname: D'Ambrosio
authors.affiliation: St. Mary's Medical Center, Huntington, WV, USA.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Memorial Healthcare System, Hollywood, FL, USA.
authors.forename: Srinath
authors.initials: S
authors.lastname: Sundararaman
authors.affiliation: Pennsylvania Hospital of University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Kolker
authors.affiliation: Mercy Health, Springfield, MO, USA.
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Creach
authors.affiliation: Crozer-Keystone Health System, Philadelphia CyberKnife, Havertown, PA, USA. rlancmd@gmail.com.
authors.forename: Rachelle
authors.identifier: http://orcid.org/0000-0001-6051-1927
authors.initials: R
authors.lastname: Lanciano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D012042:Registries / Q000706:statistics & numerical data*; D015996:Survival Rate; D055815:Young Adult