Characterization of FDG-PET images after stereotactic body radiation therapy for lung cancer

Radiother Oncol. 2010 Nov;97(2):200-4. doi: 10.1016/j.radonc.2010.04.011. Epub 2010 Apr 27.


Background and purpose: The purpose was to characterize (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) findings after stereotactic body radiation therapy (SBRT) for lung cancer.

Materials and methods: This was a retrospective review of 32 FDG-PET scans from 23 patients who underwent SBRT for lung cancer and who showed no evidence of local recurrence. The FDG uptake by lesions was assessed visually using a 3-point scale (0, none or faint; 1, mild; or 2, moderate to intense), and the demarcation (ill- or well-defined) was evaluated. For semi-quantitative analysis, the maximum standardized uptake value (SUVmax) was calculated.

Results: Grade 2 intensity was observed in 70%, 33%, 30%, and 0% of PET scans performed <6, 6-12, 12-24, and >24 months, respectively, after SBRT; well-defined demarcation was observed in 80%, 33%, 40%, and 17%, respectively, and the respective means of the SUVmax were 4.9, 2.6, 3.0, and 2.3. The SUVmax was significantly higher for scans performed at <6 months than at 6-12 or >24 months.

Conclusions: FDG uptake tended to be intense and well-defined at early times after SBRT, especially within 6 months, and was faint and ill-defined at later periods. Moderate to intense FDG uptake observed soon after SBRT does not always indicate a residual tumour.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma / radiotherapy
  • Aged
  • Aged, 80 and over
  • Carcinoma, Squamous Cell / diagnostic imaging*
  • Carcinoma, Squamous Cell / radiotherapy
  • Female
  • Fluorodeoxyglucose F18* / metabolism
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / radiotherapy
  • Male
  • Middle Aged
  • Positron-Emission Tomography*
  • Radiography
  • Retrospective Studies


  • Fluorodeoxyglucose F18