1Department of Pediatric Oncology and Hematology, Medical University of Bialystok, Białystok, Poland
2Department of Pediatrics, Hematology and Oncology, Medical University of Gdansk, Gdansk, Poland
3Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland
4Department of Pediatric Oncology, Hematology and Transplantology University of Medical Sciences, Poznan, Poland
5Department of Bone Marrow Transplantation, Oncology and Hematology, Medical University of Wroclaw, Wroclaw, Poland
6Department of Pediatric Oncology, Children’s Memorial Health Institute, Warsaw, Poland
7Department of Hematology, Oncology and Pediatric Bone Marrow Transplantation, Medical University of Lublin, Lublin, Poland
8Department of Pediatric Oncology and Hematology, County Hospital, Olsztyn, Poland
9Department of Pediatrics, Hematology and Oncology, Medical University of Szczecin, Szczecin, Poland
10Department of Pediatrics, Hematology and Oncology, Medical University of Zabrze, Zabrze, Poland
11Center of Pediatrics and Oncology by Dr E. Hanke, Chorzow, Poland