[1] Morehouse Sch Med, Atlanta, GA USA
[2] Emory Univ, Dept Radiat Oncol, Winship Canc Inst, Atlanta, GA USA
[3] Mayo Clin, Dept Radiat Oncol, Rochester, MN USA
[4] Univ Washington, Dept Radiat Oncol, Fred Hutchinson Canc Ctr, Seattle, WA USA
[5] Mem Sloan Kettering Canc Ctr, New York, NY USA
[6] Univ Texas MD Anderson Canc Ctr Houston, Dept Radiat Oncol, Houston, TX USA
[7] Univ Penn, Perelman Sch Med, Dept Radiat Oncol, Philadelphia, PA USA
[8] Northwestern Med Chicago Proton Ctr, Warrenville, IL USA
[9] Univ Florida, Dept Radiat Oncol, Coll Med, Jacksonville, FL USA
[10] MD Anderson Canc Ctr Houston, Houston, TX USA
[11] Texas Oncol, Texas Ctr Proton Therapy, Irving, TX USA
[12] Harvard Med Sch, Massachusetts Gen Hosp, Dept Radiat Oncol, Boston, MA USA