Validation of 18F-MISO-PET and 18F-FLT-PET

Hypoxia and tumor cell proliferation are important mechanisms contributing to resistance to radiotherapy in human head and neck tumor cells. Currently, assessment of these two tumor characteristics is performed in biopsies using immunohistochemical staining and subsequent analysis. A promising non-invasive method of characterizing a tumor is the use of positron-emission tomography (PET). Specific tracers can be used to detect hypoxia and proliferative activity. 18F-misonidazole is a tracer for hypoxia and 18F-thymidine is a tracer for proliferation. Patients suffering from head and neck cancer and who will undergo surgery will be included in this study. One week before the surgery the patients will undergo a CT-scan and a PET-scan with either of the tracers. Shortly before the surgery they will be given immunohistochemically detectable marker substances enabling the characterization of the tumor samples gathered from the resection specimen. These markers are pimonidazole for detection of hypoxia and iododeoxyuridine for detection of tumor cell proliferation. The data collected by PET-scan will be analysed and compared to the results acquired by immunohistochemistry.