Hypoxia-imaging with (18)F-Misonidazole and PET: changes of kinetics during radiotherapy of head-and-neck cancer

Radiother Oncol. 2007 Jun;83(3):406-10. doi: 10.1016/j.radonc.2007.05.014. Epub 2007 May 31.


Background and purpose: PET with (18)F-Misonidazole (FMISO-PET) is a non-invasive method for measuring tumor hypoxia. We analysed changes of FMISO-uptake during radiotherapy and their impact on patient outcome.

Materials and methods: Fourteen patients with HNC underwent repeated FMISO-PET prior to radiotherapy and after 30Gy. Dynamic and static PET-scans (2+4h p.i.) were acquired. FMISO-uptake was quantified by calculating standard uptake values (SUV) and tumor-muscle-ratios (TMR). Kinetic curve types representing tissue hypoxia were defined. Change of curve type was correlated with patient outcome.

Results: The mean SUV 4h p.i. and the TMR decreased significantly during radiotherapy. SUV decreased clearly in 12/14 patients, and increased in 2 patients. TMR decreased in 11 patients, and increased in 3 patients. Prior to radiotherapy, three different shapes of kinetic curve types indicative for the degree of hypoxia could be defined in 12/14 patients: (1) accumulation type (severe hypoxia (n=8)), (2) intermediate type (intermediate degree of hypoxia (n=3)), and (3) wash-out type (low degree of hypoxia (n=1)). Curve type changed towards a lower degree of hypoxia at 30Gy in all but 3 patients. In three patients curve type remained unchanged.

Conclusions: The changes in tumor FMISO-uptake during radiotherapy indicate radio-induced reoxygenation.

MeSH terms

  • Aged
  • Carcinoma, Squamous Cell / diagnostic imaging
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / radiotherapy*
  • Cell Hypoxia*
  • Female
  • Fluorine Radioisotopes
  • Head and Neck Neoplasms / diagnostic imaging
  • Head and Neck Neoplasms / metabolism
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Misonidazole / pharmacokinetics*
  • Positron-Emission Tomography / methods*
  • Prospective Studies
  • Radiation-Sensitizing Agents / pharmacokinetics*


  • Fluorine Radioisotopes
  • Radiation-Sensitizing Agents
  • Misonidazole