1. Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, No. 123, Ta-Pei Road, Niao-Sung, Kaohsiung 833, Taiwan
2. Biomedical Imaging and Instrumentation Laboratory, Department of Biomedical Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan
3. Medical Device Innovation Center, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan