Study population
We retrospectively reviewed the charts of children ages 3 to 18 years with histopathologically confirmed MB at the INCA in Rio de Janeiro, Brazil. The inclusion criteria was patients with confirmed diagnosis of MB between January 1997 through December 2016, with ages 3-18 years. The sample was limited to patients who received full adjuvant tratement at INCA, therefore we excluded patients who had previously received chemotherapy or radiation therapy elsewhere. Patients with surgeries in other hospitals were included. An initial search revealed 134 patients who met inclusion criteria. After 20 patients being excluded (5 due to missing data; 6 due to lack of any treatment besides surgery, because of clinical conditions; 5 due to treatment in another institution; 4 with admission just for radiation therapy), a total of 114 patients were included for analysis. The study was approved by the Hospital ethics committee.