title: Incidence and risk factors for chest wall toxicity after risk-adapted stereotactic radiotherapy for early-stage lung cancer.
abstract: BACKGROUND
  High local control rates are reported after stereotactic ablative body radiotherapy (SABR) in stage I non-small cell lung cancer. Toxicity is uncommon, but few reports on long-term follow-up are available. We studied the incidence of chest wall pain (CWP) and rib fractures in patients with long-term follow-up.
  
  
  METHODS
  Between 2003 and 2009, 500 patients (530 tumors) underwent SABR using risk-adapted fractionation schemes, consisting of three fractions of 20 Gy, five fractions of 12 Gy, or eight fractions of 7.5 Gy. Toxicity data were collected in a prospective database and scored using Common Terminology Criteria for Adverse Events (CTCAE) version 4.03. Chest wall volumes receiving doses of 30, 40, 45, and 50 Gy (V30 Gy-V50 Gy) and maximum dose in 2 cm of chest wall (D2 ml) were determined for patients with CWP or rib fractures (n = 57).
  
  
  RESULTS
  With a median follow-up of 33 months, the 3-year overall survival and local control rates were 53.1% and 90.4%, respectively. CWP developed in 11.4% of patients and was severe (grade 3) in 2.0%. Rib fractures were observed in eight patients (1.6%), accompanied by CWP in seven of these patients. On multivariate analysis, patients with CWP had larger treatment volumes and shorter tumor-chest wall distances, whereas patients with rib fractures had larger tumor diameters and treatment volumes. Grade 3 CWP and rib fractures were associated with larger volumes of chest wall receiving doses of 30 to 50 Gy and rib fractures specifically with a higher maximum dose in the chest wall.
  
  
  CONCLUSIONS
  Severe (grade 3) chest wall toxicity is uncommon after risk-adapted SABR and manifests in 2% or fewer of patients.
authors: Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands. e.bongers@vumc.nl
authors: Eva M
authors: EM
authors: Bongers
authors: Cornelis J A
authors: CJ
authors: Haasbeek
authors: Frank J
authors: FJ
authors: Lagerwaard
authors: Ben J
authors: BJ
authors: Slotman
authors: Suresh
authors: S
authors: Senan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010146:Pain / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects*; D012253:Rib Fractures / Q000209:etiology*; D012307:Risk Factors; D035441:Thoracic Wall / Q000528:radiation effects