1. Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan
2. Department of Radiotherapy, Cheng Hsin General Hospital, Taipei 112, Taiwan
3. Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 111, Taiwan
4. Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu 112, Taiwan