RecruitingPhase 3Diagnostic testA Study Comparing Personalized Radiation Therapy With Standard Radiation Therapy in People With HPV-Positive Throat CancerThe researchers are doing this study to find out if a personalized approach to chemoradiation therapy (which may include a lower dose of radiation) is as effective as the standard chemoradiation therapy in people with HPV-positive throat cancer. Other purposes of this study include looking at the following: * Whether a lower dose of radiation in combination with standard chemotherapy causes fewer side effects than the standard dose of radiation therapy in combination with standard chemotherapy * How the study approaches (lower dose of radiation therapy + standard chemotherapy and standard dose of radiation therapy + standard chemotherapy) affect participants' quality of life. The researchers will measure quality of life by having participants fill out questionnaires.