Affiliation: | 1. Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba, Japan;2. Nagoya Proton Therapy Center, Nagoya, Japan;3. Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Japan;4. Department of Otolaryngology, Chiba University School of Medicine, Chiba, Japan |