1. Department of Pediatric Oncology; Manuel de Jesus Rivera Hospital; Managua Nicaragua
2. Department of Pediatrics; San Gerardo Hospital; University of Milano-Bicocca; Fondazione MBBM Monza Italy
3. Department of Health Science; Center of Biostatistics; University of Milano-Bicocca; Milano Italy
4. Consorzio Mario Negri Sud; Santa Maria Imbaro; Italy
5. Oncology Institute of Southern Switzerland (IOSI); Bellinzona; Switzerland