Serial FDG-PET on patients with head and neck cancer: implications for radiation therapy

Int J Radiat Biol. 2009 Sep;85(9):796-804. doi: 10.1080/09553000903039180.


Purpose: To assess possible consequences for radiotherapy (RT) planning, e.g., reduction of treatment volume by a decreased tumour volume in Fluor-18-fluoro-deoxy-glucose-Positron emission tomography (FDG-PET) based on a close-meshed evaluation of FDG uptake in primary head and neck cancer (HNC) during RT.

Materials and method: PET data were analysed using a source-to-background based algorithm. The following parameters were obtained: max. standardised uptake value (SUVmax), PET-based gross tumour volume (GTV-PET) and metabolic volume (MV).

Results: While the median SUVmax decreased (initial: 15.2, 1st/2nd week: 10.2, 3rd/4th week: 6.5, 5th/6th week: 6.4), the median values of GTV-PET (9.3 cm(3), 12.4 cm(3), 14.0 cm(3), 17.9 cm(3)) and MV (92.2 cm(3), 61.7 cm(3), 60.0 cm(3), 71.3 cm(3)) seemed to increase during radiotherapy. The intra-individual development of SUVmax could be divided into two groups: group A having continuously decreasing values of SUVmax (n = 10 patients), and group B having a temporary increase of SUVmax (n = 13).

Conclusions: Data suggest that a reduction of treatment volume is not possible by an adaptive re-planning based on FDG-PET, e.g., at 50 Gy. This may be caused by a consecutive therapy associated inflammation. This limitation is probably related to the use of a source-to-background based algorithm.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biological Transport / radiation effects
  • Female
  • Fluorodeoxyglucose F18 / metabolism*
  • Head and Neck Neoplasms / diagnostic imaging*
  • Head and Neck Neoplasms / metabolism
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Male
  • Middle Aged
  • Positron-Emission Tomography
  • Radiotherapy Planning, Computer-Assisted
  • Time Factors
  • Tumor Burden / radiation effects


  • Fluorodeoxyglucose F18