[1] Chungbuk Natl Univ, Coll Med, Dept Pediat, Cheongju, South Korea
[2] Natl Canc Ctr, Ctr Pediat Oncol, Goyang Si 410769, Gyeonggi Do, South Korea
[3] Natl Canc Ctr, Hematol & Oncol Clin, Goyang Si 410769, Gyeonggi Do, South Korea
[4] Inje Univ, Haeundae Paik Hosp, Dept Pediat, Pusan, South Korea
[5] Chungnam Univ Hosp, Dept Pediat, Taejon, South Korea
[6] Natl Canc Ctr, Dept Diagnost Lab Med, Goyang Si 410769, Gyeonggi Do, South Korea