1International School of Beaverton, Beaverton, OR, United States, 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 3Department of Radiation Oncology, U.T. MD Anderson Cancer Center, Houston, TX, United States, 4Department of Imaging Physics, U.T. MD Anderson Cancer Center, Houston, TX, United States, 5Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, United States, 6Department of Radiation Physics, U.T. MD Anderson Cancer Center, Houston, TX, United States, 7Department of Head and Neck Surgery, U.T. MD Anderson Cancer Center, Houston, TX, United States, 8Harvard Medical School, Boston, MA, United States