[1] Yeungnam Univ, Coll Med, Dept Radiat Oncol, Taegu, South Korea
[2] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Radiat Oncol, Seoul, South Korea
[3] Natl Canc Ctr, Res Inst & Hosp, Proton Therapy Ctr, Goyang, South Korea
[4] Seoul Natl Univ, Coll Med, Dept Radiat Oncol, Seoul, South Korea
[5] Seoul Natl Univ, Coll Med, Dept Internal Med, Seoul 151, South Korea
[6] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Med,Div Hematol Oncol, Seoul, South Korea
[7] Yonsei Univ, Coll Med, Dept Radiat Oncol, Seoul 03722, South Korea
[8] Catholic Univ Korea, Seoul St Marys Hosp, Coll Med, Dept Radiat Oncol, Seoul, South Korea
[9] Catholic Univ Korea, Seoul St Marys Hosp, Coll Med, Dept Med Oncol, Seoul, South Korea
[10] Ajou Univ, Sch Med, Dept Radiat Oncol, Suwon 441749, South Korea
[11] Catholic Univ Korea, Yeouido St Marys Hosp, Coll Med, Dept Radiat Oncol, Seoul, South Korea
[12] Catholic Univ Korea, St Vincents Hosp, Coll Med, Dept Radiat Oncol, Seoul, South Korea
[13] Keimyung Univ, Sch Med, Dongsan Med Ctr, Dept Radiat Oncol, Taegu, South Korea