[1] Princess Margaret Canc Ctr, Dept Radiat Oncol, Toronto, ON, Canada
[2] NRG Oncol, Philadelphia, PA USA
[3] Univ Colorado Denver, Dept Radiat Oncol, Aurora, CO USA
[4] Univ Texas Southwestern Med Ctr Dallas, Dallas, TX 75390 USA
[5] Washington Univ, St Louis, MO USA
[6] Pocono Canc Ctr, East Stroudsburg, PA USA
[7] Mayo Clin, Rochester, MN USA
[8] Radiol Associates Sacramento, Sutter Med Grp, Sacramento, CA USA
[9] Roswell Pk Canc Inst, Buffalo, NY 14263 USA
[10] Cleveland Clin, Cleveland, OH 44106 USA
[11] Univ Maryland Med Syst, Baltimore, MD USA
[12] Ottawa Hosp, Ottawa, ON, Canada
[13] Arizona Oncol Serv Fdn, Tucson, AZ USA
[14] Princess Margaret Hosp, Toronto, ON, Canada
[15] Univ Calif Davis, Ctr Comprehens Canc, Sacramento, CA 95817 USA
[16] Beaumont Hlth Syst, Royal Oak, MI USA
[17] Univ Pittsburgh, Inst Canc, Pittsburgh, PA USA
[18] Princess Margaret Canc Ctr, Toronto, ON, Canada