The Role of Radiotherapy, Chemotherapy, and Targeted Therapies in Adult Intramedullary Spinal Cord Tumors.

Intramedullary primary spinal cord tumors are rare in adults and their classification has recently evolved. Their treatment most frequently relies on maximal safe surgical resection. Herein, we review, in light of the WHO 2021 classification of central nervous system tumors, the knowledge regarding the role of radiotherapy and systemic treatments in spinal ependymomas, spinal astrocytomas (pilocytic astrocytoma, diffuse astrocytoma, spinal glioblastoma IDH wildtype, diffuse midline glioma H3-K27M altered, and high-grade astrocytoma with piloid features), neuro-glial tumors (ganglioglioma and diffuse leptomeningeal glioneuronal tumor), and hemangioblastomas. In spinal ependymomas, radiotherapy is recommended for incompletely resected grade 2 tumors, grade 3 tumors, and recurrent tumors not amenable to re-surgery. Chemotherapy is used in recurrent cases. In spinal astrocytomas, radiotherapy is recommended for incompletely resected grade 2 astrocytomas and grade 3 or 4 tumors as well as recurrent tumors. Chemotherapy is indicated for newly diagnosed high-grade astrocytomas and recurrent cases. In hemangioblastomas not amenable to surgery, radiotherapy is an effective alternative option. Targeted therapies are playing an increasingly important role in the management of some intramedullary primary spinal cord tumor subtypes. BRAF and/or MEK inhibitors have demonstrated efficacy in pilocytic astrocytomas and glioneuronal tumors, belzutifan in von Hippel-Lindau-related hemangioblastomas, and promising results have been reported with ONC201 in diffuse midline glioma H3-K27M altered.