[1] Associates Med Phys, John R Marsh Canc Ctr, Hagerstown, MD USA
[2] John R Marsh Canc Ctr, Radiat Oncol, Hagerstown, MD USA
[3] Johns Hopkins Univ, Dept Radiol, Baltimore, MD USA
[4] St Elisabeth, Radiat Oncol, Pl Louise Godin, Namur, Belgium
[5] Univ Tokyo Hosp, Dept Radiol, Tokyo, Japan
[6] Associates Med Phys, Radiat Oncol, Lanham, MD USA
[7] Georgetown Univ, Georgetown, Guyana
[8] Univ Washington, Med Ctr, Radiat Oncol Ctr, Seattle, WA 98195 USA