Neuroscience Clerkship

TREATMENT OF CNS TUMORS

Surgery

● Biopsy – needle biopsy, often with frameless MRI guidance

● Subtotal Resection – debulking to decrease mass effect and improve symptoms. May not change overall prognosis.

● Gross Total Resection – for most tumors (except CNS lymphoma, germinoma), the prognosis is significantly improved by gross total tumor resection. Benefits of resection for tumor control must be balanced against minimizing neurologic deficits.

Radiation

● Cranial – whole brain radiation often used for metastatic disease. Delayed (>2 yrs) cognitive decline in about 10%

● Focal – fractionated radiation to involved area of brain or spine to limit microscopic growth while minimizing damage to normal tissue and exposure of uninvolved areas

● Stereotactic – linear accelerator or gamma knife used to deliver ablative dose to small (<4 cc³) defined area
 

Chemotherapy

● Highly effective for very few tumors (e.g., oligodendroglioma with specific genetic abnormalities (LOH 1p & 19 q); procarbazine, lomustine, vincristine (PCV); chemosensitive tumor survival from diagnosis >10 yrs

● Used as adjunct for many tumors, but relatively ineffective:

Most gliomas

CNS lymphoma

Primitive neuroectodermal tumors (medulloblastoma)

Germ cell tumors