title: Radiological changes after stereotactic radiotherapy for stage I lung cancer.
abstract: BACKGROUND
  Stereotactic body radiation therapy (SBRT) is entering routine clinical use for selected patients with early-stage non-small cell lung cancer. Post-SBRT radiological changes are commonly seen on follow-up computed tomography (CT) imaging and can cause diagnostic dilemmas. The aim of this study is to describe the incidence, radiological severity, and long-term morphology of these changes.
  
  
  METHODS
  CT scans from patients treated between 2003 and June 2008 were eligible for evaluation if radiological follow-up had been performed at our center for at least 2 years, and there was no definite evidence of local recurrence. Timing, incidence, morphology, and severity of lung changes were determined.
  
  
  RESULTS
  CT scans from 61 patients (68 lesions) with a median follow-up of 2.5 years were evaluated. Within 6 months, 54% of lesions were associated with additional radiological abnormalities, and this figure reached 99% after 36 months. Most changes were scored as mild to moderate, and although the median time to first observation was 17 weeks, 25% appeared ≥ 1 year post-SBRT. In 47% of lesions, the morphology or severity of changes continued to evolve more than 2 years posttreatment.
  
  
  CONCLUSIONS
  Mild-moderate radiological changes are common after lung SBRT. Some degree of late change is nearly universal, and it often continues to evolve more than 2 years post-SBRT. Clinicians should be aware of these radiological findings, which need to be distinguished from the uncommon cases of local failure post-SBRT.
authors.affiliation: Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands. m.dahele@vumc.nl
authors.forename: Max
authors.initials: M
authors.lastname: Dahele
authors.forename: David
authors.initials: D
authors.lastname: Palma
authors.forename: Frank
authors.initials: F
authors.lastname: Lagerwaard
authors.forename: Ben
authors.initials: B
authors.lastname: Slotman
authors.forename: Suresh
authors.initials: S
authors.lastname: Senan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000556:secondary / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000150:complications / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000209:etiology; D017564:Radiation Pneumonitis / Q000175:diagnosis* / Q000209:etiology; D019275:Radiopharmaceuticals; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18