[1] Case Western Reserve Univ, Univ Hosp Cleveland, Dept Radiat Oncol, Cleveland, OH 44122 USA
[2] Univ Quebec, Ctr Hosp, Dept Radiat Oncol, Quebec City, PQ G1R 2J6, Canada
[3] Purdue Univ, Sch Ind Engn & Aeronaut & Astronaut, W Lafayette, IN 47907 USA
[4] Harvard Univ, Sch Med, Dept Radiat Oncol, Boston, MA 02115 USA
[5] Vanderbilt Univ, Dept Radiat Oncol, Nashville, TN 37232 USA
[6] Thomas Jefferson Univ, Dept Radiat Oncol, Philadelphia, PA 19107 USA
[7] Robarts Res Inst, Dept Imaging Res, London, ON N6A 5K8, Canada
[8] Queens Univ, Sch Comp Sci, Kingston, ON K7L 3N6, Canada
[9] Philips Radiat Oncol Syst, Fitchburg, WI 53711 USA
[10] Univ Utrecht, Med Ctr, Dept Radiotherapy, NL-3508 GA Utrecht, Netherlands
[11] Yale Univ, Sch Med, Dept Therapeut Radiol, New Haven, CT 06520 USA
[12] Tufts Univ, Sch Med, Dept Radiat Oncol, Boston, MA 02111 USA
[13] Univ British Columbia, Dept Elect & Comp Engn, Vancouver, BC V6T 1Z4, Canada
[14] Johns Hopkins Univ, Sch Med, Dept Radiat Oncol, Baltimore, MD 21231 USA
[15] Univ Wisconsin, Dept Med Phys, Madison, WI 53705 USA
[16] Thomas Jefferson Univ, Dept Radiat Oncol, Philadelphia, PA 19107 USA