Radiological changes after stereotactic radiotherapy for stage I lung cancer

J Thorac Oncol. 2011 Jul;6(7):1221-8. doi: 10.1097/JTO.0b013e318219aac5.


Introduction: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / complications
  • Carcinoma, Non-Small-Cell Lung / secondary
  • Carcinoma, Non-Small-Cell Lung / surgery*
  • Female
  • Fluorodeoxyglucose F18
  • Follow-Up Studies
  • Humans
  • Lung Neoplasms / complications
  • Lung Neoplasms / pathology
  • Lung Neoplasms / surgery*
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / complications
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Recurrence, Local / surgery*
  • Neoplasm Staging
  • Positron-Emission Tomography
  • Prognosis
  • Pulmonary Fibrosis / diagnosis*
  • Pulmonary Fibrosis / etiology
  • Radiation Pneumonitis / diagnosis*
  • Radiation Pneumonitis / etiology
  • Radiopharmaceuticals
  • Radiosurgery / adverse effects*
  • Retrospective Studies
  • Tomography, X-Ray Computed*


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18