[1] Hosp Escuela Univ, Dept Pediat Hematooncol, Tegucigalpa, Honduras
[2] Manuel de Jesus Rivera Hosp, Dept Pediat Oncol, Managua, Nicaragua
[3] Francisco Marroquin Univ, Sch Med, Natl Pediat Oncol Unit, Guatemala City, Guatemala
[4] Dr Robert Reid Cabral Childrens Hosp, Dept Hematol Oncol, Santo Domingo, Dominican Rep
[5] Hosp Benjamin Bloom, Dept Oncohematol, San Salvador, El Salvador
[6] Hosp Mario Catarino Rivas, Hematooncol Serv, San Pedro Sula, Honduras
[7] St Jude Childrens Res Hosp, Dept Oncol, Leukemia Lymphoma Div, 332 N Lauderdale St, Memphis, TN 38105 USA
[8] St Jude Childrens Res Hosp, Global Pediat Med Program, 332 N Lauderdale St, Memphis, TN 38105 USA
[9] Hosp Pediat SAMIC Prof Dr Juan P Garrahan, Buenos Aires, DF, Argentina