How do you approach decision making in terms to adjuvant chemotherapy after CSI in adult medulloblastoma?

Medulloblastoma is a chemotherapy sensitive disease. The NCCN guidelines have options for CSI alone or followed by chemotherapy for standard risk disease (M0, residual disease <1.5cm2, classic or desmoplastic histology) and recommend post-CSI chemotherapy for high risk disease. Unfortunately, 25% of...