PET-MRI Assessment of Early Tumor Response to Predict Outcomes of HPV-Positive Oropharynx Cancer Patients

Intensity modulated radiotherapy (IMRT) will be delivered over 6.5 weeks in 33 daily fractions. Treatments will be initiated on Monday or Tuesday. Missed treatments will be compensated for by delivering an additional BID treatment during the week given at least 6 hours apart OR treating on the Saturday of that week, OR adding to the end of treatment. Gross disease will receive 70 Gy in 2.12 Gy fractions, areas at high-risk for subclinical disease will receive 60 Gy in 1.82 Gy fractions, and areas at low-risk for harboring subclinical disease will receive 56 Gy in 1.70 Gy fractions.

All imaging data will be acquired using a 3.0T PET-MRI scanner with a standard bore size of 60 cm. Patients will be placed in standard non-ferrous head and neck immobilization devices during PET-MRI to simulate their anticipated positioning during subsequent CT simulation and treatment. A head and neck PET-MRI study will be performed with scan sequences tailored for the site of interest. The PET-MRI exam will take approximately 90 minutes to complete.