Adaptive De-intensified Radiotherapy Using Circulating Tumor DNA in HPV- Associated Oropharyngeal Cancer

This phase II trial studies how well using circulating tumor deoxyribonucleic acid (DNA) to guide lower dose radiation therapy works in treating patients with human papillomavirus infection (HPV)-associated oropharyngeal cancer. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Recently, a blood test has been developed to detect the human papillomavirus in the blood and determine how many viral particles are present. Researchers want to compare any good and bad effects of using the lower dose radiation therapy with chemotherapy compared to the usual standard of care dose chemotherapy in patients who clear the human papillomavirus particles from their blood.