[1] Tokyo Metropolitan Childrens Med Ctr, Natl Ctr Global Hlth & Med, Dept Pediat, Tokyo, Japan
[2] Tokyo Metropolitan Childrens Med Ctr, Dept Pediat Hematol Oncol, Tokyo, Japan
[3] Keio Univ, Dept Pediat, Sch Med, Tokyo, Japan
[4] Osaka Womens & Childrens Hosp, Dept Hematol Oncol, Osaka, Japan