[1] Kyushu Univ, Grad Sch Med Sci, Dept Orthopaed Surg, Higashi Ku, Fukuoka 8128582, Japan
[2] Natl Canc Ctr, Ctr Canc Control & Informat Serv, Clin Trials & Practice Support Div, Tokyo 104, Japan
[3] Komagome Hosp, Tokyo Metropolitan Canc & Infect Dis Ctr, Dept Pediat, Tokyo, Japan
[4] Kyoto Univ Hosp, Div Clin Trial Management, Translat Res Ctr, Kyoto 606, Japan