Low levels of oxygen (a condition called “hypoxia”) in areas of head and neck cancers can make these tumors more resistant to radiation treatment. A recent imaging technique using a hypoxia tracer called “fluoro-misonidazole” (FMISO) can detect these low-oxygen areas within the tumor. This imaging technique, called a positron emission tomography (PET) scan, uses positively charged particles to detect slight changes in the body. FMISO PET scans have been performed in patients with head and neck cancer, and have demonstrated the ability to detect these low-oxygen areas within a tumor.
A prior study using FMISO PET showed that low-oxygen areas in a tumor disappeared by the fourth week of head and neck cancer treatment. In this study, investigators will use FMISO PET scanning to see if low-oxygen areas disappear even earlier during cancer treatment. Patients will have a scan before cancer treatment, and some patients will have a second scan five to ten days into therapy, depending on the results of the first scan.
In addition, patients will be treated differently depending on whether or not their cancers contain the human papilloma virus (HPV). Patients with HPV-positive cancers do not require the traditional high doses of radiation therapy. Therefore, patients who have no evidence of hypoxia and whose tumors are HPV-positive will receive reduced-dose radiation therapy to minimize side effects. They will also have some neck lymph nodes removed to ensure that there has been no decrease in local control despite reducing the radiation dose.