1. Department of Radiation Oncology China Medical University Hospital Taichung Taiwan
2. Department of Biomedical Imaging and Radiological Sciences National Yang‐Ming University Taipei Taiwan
3. Department of Biomedical Imaging and Radiological Science China Medical University Taichung Taiwan
4. Department of Radiation Oncology Montefiore Medical Center Bronx New York
5. Department of Medicine China Medical University Taichung Taiwan