[1] Univ Texas Southwestern Med Ctr, Dept Radiat Oncol, Dallas, TX USA
[2] Ghent Univ Hosp, Dept Radiat Oncol, Ghent, Belgium
[3] Guys & St Thomas NHS Trust, Dept Clin Oncol, London, England
[4] Queens Univ, Dept Oncol, Kingston, ON, Canada
[5] Univ Toronto, Princess Margaret Canc Ctr, Dept Radiat Oncol, Radiat Med Program,UHN, Toronto, ON, Canada
[6] Amer Soc Radiat Oncol, Arlington, VA USA
[7] Univ Texas Southwestern, Dept Radiat Oncol, 2280 Inwood Rd, Dallas, TX 75390 USA