General CNS cancer

Supratentorial

Houses the cerebral hemispheres, sella, pineal, and upper brainstem

Infratentorial

Houses the lower brainstem, pons, medulla, and cerebellum and leads to the upper spinal cord

Tentorium

The outer covering of the brain and separates these two compartments

How many ventricles are there?

4

What do the ventricles produce?

CSF

Gray matter

Made up of supportive nerve cells and makes up the outer portion of the cerebrum

White matter

Made up of bundles of nerve fibers and axons and dendrites

Circle of Willis

The main source of blood supply to the brain, which is made up of the internal carotid and vertebral arteries

Frontal lobe controls …

Executive functions like concentration, thinking, problem solving and judgment

Motivation, emotions, muscle strength, behavior

Parietal lobe controls …

Sensations on opposite side of body, ability to express self w/ and understand spoken language, process sensory information

Occipital lobe controls …

Sight and processing info from eyes, such as recognizing images

Temporal lobe controls …

Processing pain and hunger, response to stress, short term memory, emotion, understanding words and directions

Brainstem controls …

Heart rate, breathing, blood pressure, swallowing, digestion

May also affect nerves, movement, function of senses

Cerebellum controls …

Speech, balance, coordination of body/arms/legs

Blood Brain Barrier (BBB)

The brain protects itself from “intruders”

Only substances that are lipid soluble can pass through

Only ________ soluble substances may pass through the BBB

Lipid

Water soluble substances may pass through the BBB if they use a ________

Carrier molecule

Tumor cells that infiltrate healthy brain tissue cannot be reached by drugs that do not ________

Cross the BBB

The spinal cord is a continuation of the ________ and forms the inferior portion of the brainstem

Medulla oblongata

The spinal cord extends …

From medulla oblongata to L1/L2

Cauda equina

Bundle of nerve roots at the inferior end of the spinal cord

Incidence of CNS tumors is ___ in brain and ___ in spinal cord

80% / 20%

CNS tumors are now the leading cause of cancer death in which age group?

Children and adolescents ages 1-19

Main etiologic factor

Age

Most brain tumors are ________

Metastatic

Origin of primary CNS tumors

Unknown

Contributing factors

*be able to name examples of each

Family history

Occupational and environmental exposures

• Pesticides

• Ionizing radiation

Lifestyle and dietary factors

• Hair dyes

• Smoking

Medical conditions

• Viral infections

• AIDS

Genetic factors

• NF1 + NF2

• Li-Fraumeni syndrome

• Von Hippel-Lindau syndrome

Clinical presentation

Initial symptom — headache (worse in the morning)

Seizures

Difficulty w/ balance

Gait

Ambulation

Focal (problems) signs are usually unilateral

Aphasia

Hemiplegia

Paresis

Aphasia

Absence or impairment of the ability to communicate

Hemiplegia

Paralysis on one side of the body

Paresis

Weakness of voluntary movement

Detection and diagnosis

History and Physical

Medical history

Family history

Social history

Neurological Exams

Fundoscopic exam using ophthalmoscope

X-rays of skull

Most common diagnostic test for CNS brain tumors?

CT

CT

Can distinguish CSF, blood, edema, and tumor from normal brain tissue (if contrast enhanced)

Provides information regarding tumor grade, growth patterns, and effects of the tumor on the skull

MRI

Likely the best noninvasive procedure*

Can differentiate between edema and surface seeding

Useful in detecting tumors less than1 cm

Can detect meningeal involvement and tumors near the skull

Good for detecting tumors in the posterior fossa, brain stem, spinal cord and defining extent of slow growing tumors

PET

Useful in determination of differences between necrosis and malignancy

Used to determine microscopic seeding to the craniospinal axis

PET uses the radionuclide fluorodeoxyglucose (FDG) to help detect lesions

Incorporates the localizing ability of CT scanning with the ability of FDG to help differentiate between various CNS lesions, infections, and degenerative processes

Biopsy

A stereotactic biopsy (procedure commonly performed during neurosurgery to guide the insertion of a needle into a specific area of the brain) allows all areas of the tumor and its borders to be studied before surgery causes changes in the appearance of the tumor

A biopsy is indicated if a lesion is deeply seated, is thought to be malignant, or occurs in older or debilitated patients who cannot tolerate a surgical procedure

CSF Level

CNS glucose level is low in the presence of highly malignant tumors or metastatic disease

Used for staging primary CNS, lymphoma, and medulloblastoma

CSF protein levels are higher in 1/3 of patients with intracranial tumors

Most important prognostic factor?

Histopathologic diagnosis

Histopathology

Intracranial tumors are considered locally malignant based on the limited space for expansion in the cranium.

Treatment of the neural axis (craniospinal) is indicated for some histopathological malignant lesions such as medulloblastoma because of the risk of metastatic seeding.

Gliomas

• Glioblastoma

• Astrocytoma

• Glioblastoma Multiforme (GBM)

Most common primary brain tumor in children

Astrocytoma

Second most common primary brain tumor in children

Medulloblastoma

Most common and deadliest brain tumor in adults

GBM

Most common brain tumor overall

Metastatic

Staging for CNS tumors

No universal staging system is currently in use

Routes of spread

Most CNS tumors tend to spread invasively

Common route of spread for medulloblastomas and PNETs is seeding via CSF into spinal and intracranial subarachnoid spaces

Most patients with CNS tumors are prescribed ________ to reduce swelling prior to surgery

Steroids

Surgery

Performed on patients whose tumors are symptomatic and offer a chance for complete resection

Debulking is indicated with a large tumor volume and if a complete resection is not possible

Limitations of surgery

Tumor location and extent, patient status, and risk of causing debilitating neurologic deficits

Patient’s chances for survival are not enhanced with partial removal and there is a greater chance of recurrence

True

Chemo drugs must be…

Lipid soluble to cross the BBB

Chemotherapy

Nitrosourea drugs are lipid soluble which allows them to cross the BBB

Some drugs are used as radiosensitizers

Can be administered orally, IV, directly into tumor bed, via direct carotid perfusion

Radiation therapy

Indicated for tumors that are incompletely excised, inaccessible from a surgical approach, and associated with metastatic lesions

Follows surgery to try to prevent tumor regrowth or recurrence

• EBRT, SRS, Interstitial brachy

• Whole brain (helmet)

• IMRT

• proton

• Craniospinal

Dose range

45-60 Gy

Whole brain tolerance

4500-5000 cGy

Partial brain tolerance

6000 cGy

Spinal cord tolerance

4500-5000 cGy

Side effects

Hair loss

Erythema, tanning, dry and moist desquamation, and edema

Drowsiness, lethargy, decreased mental status

Hormone insufficiency (pituitary)

Brain necrosis — late serious radiation reaction after doses of 7000cGy

Most common radiation side effect

Fatigue

Most important factors in prognosis

Age

Performance status

Tumor type