Principles and Practice of Radiation Therapy Chapter 34 Central Nervous System Tumors Copyright © 2010 by Mosby, Inc., an affiliate of Elsevier Inc.

Central Nervous System General information Neuron Divisions Central Peripheral

General Information Functions Divisions Control and coordination Receives and relays information Divisions

Neuron Cell parts Cell body Dendrite Axon Myelin sheath

Neuron Types Sensory Motor Interneuron

Central Nervous System General information Patterns of organization Sensory vs. motor White matter vs. gray matter

Central Nervous System Brain Glial cells Blood-brain barrier Energy usage

Central Nervous System Functional divisions of the brain Hindbrain Midbrain Forebrain Reticular formation

Central Nervous System Anatomic divisions of the brain Meninges Cerebrospinal fluid (CSF)

Central Nervous System Anatomic divisions of the brain Cerebrum Hemispheres Corpus callosum Lobes

Central Nervous System Anatomic divisions of the brain Cerebellum Function

Central Nervous System Anatomic divisions of the brain Brain stem Diencephalon Medulla oblongata Pons Midbrain

Central Nervous System Anatomic divisions of the brain Limbic system Thalamus Hypothalamus

Central Nervous System Anatomic divisions of the brain Spinal cord

Peripheral Nervous System Divisions Sensory vs. motor Somatic vs. autonomic Sympathetic vs. parasympathetic

Central Nervous System Cancers All central nervous system (CNS) tumors Glioblastoma multiforme (GBM) Spinal cord tumors Metastatic brain lesions General information Epidemiology Etiology Clinical presentation Detection and diagnosis Pattern of spread Disease classification Treatment Survival

General Information CNS tissue Neurons Glial cells Astrocytes Oligodendrocytes Ependymal cells Microglia

General Information CNS tissue Meninges Schwann cells Choroid plexus Lymphocytes

Epidemiology Incidence 20,500 new cases Deaths 12,700 deaths Pregnancy

Etiology Cause Risk factors Unknown Age Radiation Genetics Other factors without clear scientific proof Electromagnetic fields Cellular telephones

Clinical Presentation Location Symptoms Headache Mental status change Seizure Others

Detection and Diagnosis Types Neurons/medulloblastomas

Detection and Diagnosis Types Glial cells/gliomas Astrocytes/astrocytomas Grading Oligodendrocytes/oligodendrogliomas Ependymal cells/ependymomas

Detection and Diagnosis Types Ganglioglioma Schwann cells/schwannoma

Detection and Diagnosis Types Chordomas Meninges/meningioma

Pattern of Spread Noncapsulating Infiltration of CSF

Disease Classification Staging Grading No standard grading system Prognosis based on cell type and grade

Treatment Surgery Chemotherapy Dexamethasone Purpose Needle biopsy Craniotomy Shunt placement Chemotherapy Chemotherapy wafers Dexamethasone

Treatment Radiation therapy External beam Indication Blocking Beam arrangement Whole-brain radiation therapy (WBRT) vs. supratentorial brain (STB) therapy Dose 5000 to 6500 cGy

Treatment Radiation therapy External beam Side effects

Treatment Radiation therapy Stereotactic radiosurgery Proton therapy Indications Proton therapy

Survival Low-grade astrocytoma Anaplastic (intermediate-grade) astrocytoma Glioblastomas Oligodendroglioma

GBM Epidemiology Most common primary brain tumor in adults Race Gender Age

GBM Etiology Cause Unknown Risk factors Radiation Genetics

GBM Clinical Presentation Location Symptoms Headache Seizure Focal neurologic deficits Mental status change

GBM Pattern of Spread Direct extension Predictable Do not metastasize

GBM Disease Classification Stage Not staged Grade Grade IV astrocytomas

GBM Treatment Surgery Chemotherapy Radiation therapy Temozolomide External beam 6000 cGy Brachytherapy Stereotactic radiosurgery (SRS)

GBM Survival No treatment – 3 months Median survival – 8.4 months Optimal therapy – 12 months Age Younger than 40 years 40 to 60 years Older than 60 years

Spinal Tumors Epidemiology Etiology Incidence Gender Age Cause 2500 new cases Gender Age Etiology Cause Unknown Risk factors Genetics

Spinal Tumors Clinical Presentation Symptoms Pain Cord compression Weakness

Spinal Tumors Detection and Diagnosis Types Epidural Intradural extramedullary Most common Intradural intramedullary

Spinal Tumors Pattern of spread Staging Direct extension Enneking Stage I Stage II Stage III

Spinal Tumors Treatment Surgery Treatment of choice Chemotherapy Radiation therapy 5000 cGy

Spinal Tumors Survival 5-year survival − 90% Cause of death

Metastatic Brain Lesions How do tumors metastasize? Source of metastases

Metastatic Brain Lesions Epidemiology and Etiology Increasing incidence Estimated 100,000 new cases Cost

Metastatic Brain Lesions Etiology Risk factors Certain cancers Age

Metastatic Brain Lesions Detection and Diagnosis Signs and symptoms Headache Seizure Loss of function Hemorrhage Asymptomatic

Metastatic Brain Lesions Detection and Diagnosis Computed tomography (CT) vs. magnetic resonance imaging (MRI)

Metastatic Brain Lesions Treatment Purpose Palliation Cause of symptoms Headache Edema Seizure

Metastatic Brain Lesions Treatment Surgery Craniotomy Indications Risks

Metastatic Brain Lesions Treatment Chemotherapy Other drugs Dexamethasone Also called Decadron

Metastatic Brain Lesions Treatment Radiation therapy WBRT Indications Radiosensitivity of tumor Dose/fractionation

Metastatic Brain Lesions Treatment Radiation therapy SRS Indications

Metastatic Brain Lesions Survival Outcome factors Survival Untreated Steroids only Surgery with WBRT Surgery alone SRS WBRT