[Early and long-term outcomes of treatment in patients with medulloblastoma]

To compare the modes of craniospinal irradiation (CSI) and to determine possible factors improving the outcome in patients with medulloblastoma.

The study included 92 patients with medulloblastoma who were treated at the Russian Research Radiology Center between 2008 and 2019. Mean age of patients was 12 years. Classical morphological variant of medulloblastoma prevailed (48.4%). After surgery, 78 patients underwent radiotherapy (CSI + full-volume «boost» on the tumor site). Standard risk patients received CSI in a reduced dose after tumor resection. Weekly modification of radiotherapy with vincristine was performed in 73 (79.3%) patients.

We significantly (p<0.05) determined the total focal doses for CSI in patients with medulloblastoma. Total resection of posterior cranial fossa tumor improved relapse-free survival by several times. Complete CSI up to total dose of 36/54 Gy ensures the most positive effect compared to irradiation in reduced dose.

Relapse-free survival significantly depends on total focal dose of CSI. Single focal dose, chemotherapeutic modification of radiotherapy and M-stage had no significant effect on relapse-free survival. Perhaps, this is due to small sample size.