Only the strong survive: therapeutic selective pressure drives medulloblastoma leptomeningeal metastasis.

Medulloblastoma (MB) is the most common malignant tumor in the central nervous system in childhood and regularly metastasizes to the leptomeninges following radiation therapy. Using patient-derived medulloblastoma models and genetically engineered mouse models, Nör et al. observed enhanced inflammation and infiltration of myeloid cells within the brain following irradiation. The authors identified inflammatory cytokines and the resulting breakdown of blood-brain barriers as the main culprits of MB leptomeningeal metastasis. This study demonstrated that targeting inflammation through the use of dexamethasone effectively reduced systemic inflammatory cytokines and the resulting radiation-induced leptomeningeal metastasis.