[1] Univ Virginia, Div Vasc & Intervent Radiol, Dept Radiol, Charlottesville, VA USA
[2] Univ Penn, Dept Biostat & Epidemiol, Philadelphia, PA 19104 USA
[3] Univ Penn, Perelman Sch Med, Philadelphia, PA 19104 USA
[4] Univ Michigan, Dept Radiat Oncol, Ann Arbor, MI 48109 USA
[5] Musculoskeletal Transplant Fdn, Dept Sterilizat, Jessup, PA USA
[6] Mem Sloan Kettering Canc Ctr, Dept Med Phys, New York, NY 10021 USA
[7] Oregon Hlth & Sci Univ, Knight Canc Inst, Dept Radiat Med, Portland, OR 97201 USA
[8] Johns Hopkins Univ, Sidney Kimmel Canc Ctr, Dept Radiat Oncol & Mol Radiat Sci, 401 North Broadway,Weinberg Suite 1440, Baltimore, MD 21231 USA