1. Tongji University Cancer Center Shanghai Tenth People's Hospital Tongji University School of Medicine Shanghai 200072 P. R. China
2. Departments of Radiology, Medical Physics, Materials Science & Engineering Pharmaceutical Sciences University of Wisconsin − Madison Madison WI 53705 USA
3. Department of Radiology Huashan Hospital Fudan University Shanghai 200040 P. R. China
4. Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers Fudan University 220 Handan Road Shanghai 200438 P. R. China
5. Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200240 P. R. China