[1] Univ N Carolina, Dept Radiat Oncol, Sch Med, Chapel Hill, NC USA
[2] Albert Einstein Coll Med, Bronx, NY USA
[3] Univ Texas Southwestern, Dept Radiat Oncol, Dallas, TX USA
[4] Univ North Carolina Hosp, Chapel Hill, NC USA
[5] Univ N Carolina, Chapel Hill, NC USA
[6] Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC USA
[7] UNC, Chapel Hill, NC USA
[8] Univ N Carolina, Sch Med, Dept Otolaryngol, Chapel Hill, NC USA
[9] UNC Sch Med, Chapel Hill, NC USA
[10] Univ Carolina, Chapel Hill, NC USA
[11] Univ N Carolina, Dept Radiat Oncol, Chapel Hill, NC USA
[12] Univ Florida, Hlth Proton Therapy Inst, Jacksonville, FL USA
[13] Univ Florida Hosp, Gainesville, FL USA
[14] Case Western Reserve Univ, Sch Med, Cleveland, OH USA