1. Department of Diagnostic and Interventional Radiology/Radiation Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan;
2. Department of Otolaryngology, Osaka City University Graduate School of Medicine, Osaka, Japan;
3. Department of Internal Medicine, Ishikawa Clinic, Osaka, Japan;
4. Department of Radiation Oncology, Osaka City General Hospital, Osaka, Japan;
5. Department of Radiation Oncology, Tane General Hospital, Osaka, Japan