1. Department of Pediatric Surgery, Traumatology and Urology, Poznan University of Medical Sciences, 60-572 Poznan, Poland
2. Department of Pediatric Oncology, Hematology and Transplantology, Poznan University of Medical Sciences, 60-572 Poznan, Poland
3. Department of Clinical Oncology, Wroclaw Medical University, 50-556 Wrocław, Poland