Brain Metastasis

• Understanding the disease
• Treatment options
• Side effects of treatment

Stephen Shamp, MD MSEE

David Bloom, MD PhD

Matthew Culbert, MD

Brain metastases: cancer that started elsewhere in the body (e.g. lung or breast) and spread to the brain

Brain primary: a normal brain cell (glial cell) becomes malignant and is called a glioma

Brain Metastases

• Most common intracranial tumors in adults
• In patients with stage IV cancer, 10 – 30% will develop brain mets

The odds of developing brain metastases based on the primary type of cancer

• Lung: 16 to 20%
• Melanoma: 7%
• Kidney: 7 to 10%
• Breast: 5%
• Colorectal: 1 to 2%
• Prostate: <1%

SYMPTOMS OF BRAIN METASTASES �

Symptom Patients % �

Headache 42

Mental change 31

Focal weakness 27

Seizure 20

Gait ataxia 17

Speech problems 10

Sensory disturbance 6

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Note that tumors usually cause symptoms on the opposite side of the body

Brain Swelling – brain tumor often cause swelling or edema which creates pressure on the brain, with headaches and nausea, steroids like Decadron (dexamethasone) will decrease this pressure

Brain Imaging

CT’s are not as good as MRI at finding Mets

CT showed edema in cerebellum

MRI the next day showed multiple mets

Brain mets are easier to see on an MRI if the patients is given IV contrast (called gadolineum)

Normally the radiologist can tell the difference between a brain tumor and a stroke (if not sometimes a biopsy is necessary)

Other Brain Tumors that are NOT cancer

Both of these are examples of a brain abscess

Sometimes a Brain Biopsy is Indicated

A new large contrast-enhancing right frontal mass in a 40-year-old woman being treated for metastatic ovarian carcinoma. She was responding well systemically to chemotherapy when she developed a left hemiparesis. This large homogeneously enhancing right frontal lesion with associated vasogenic edema and central restricted diffusion was identified.

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Given atypical clinical and radiologic features, biopsy was performed and revealed lymphoma. 

Brain Metastases are Usually Multiple

Brain Radiation

Depending on the type and number of brain tumors, options include radiation to the whole brain, or partial brain with highly targeted radiation (called stereotactic radiosurgery)

www.nccn.org

CT simulation (planning session)

• We will build a mask to hold you in the same position with each treatment.
• Temporary marks will be made
• CT images are obtained and then imported into the treatment planning computer
• Your MRI may be fused to help with targeting

Logistics of Whole Brain Radiation:

• Usually 10 daily treatments
• Treatment days are Monday-Friday 5 days per week, 2 weeks in total
• Daily treatment takes 15 minutes or less. You will be given a schedule
• You do not feel anything during treatment, you will not be radioactive

Logistics of Stereotactic Radiosurgery (SRS):

• Usually 1-5 treatments in total
• Treatment days are Monday-Friday, 3 days per week, 1-2 weeks in total
• Daily treatment takes 15 minutes or less. You will be given a schedule
• You do not feel anything during treatment, you will not be radioactive

• Lasers and/or imaging is used to precisely deliver the daily radiation treatment.
• Expect to be on the treatment table less than 15 minutes.
• You will not feel any immediate effects.

Side Effects of Brain Radiation

• Common:
• Fatigue
• Hair Loss (local for SRS, diffuse for WBRT)
• Scalp Irritation
• Possible:
• Headaches
• Nausea
• Worsening Neurological symptoms

Risks of Brain Radiation

• Radiation Necrosis (Injury to surrounding brain)
• Memory / Neurocognitive Decline

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• Depending on area treated other structures may be at risk of rare but serious injury including optic nerves/chiasm, brainstem, cochlea, brainstem, pituitary, secondary malignancy

The response or benefit from brain radiation may take several weeks to months

Radiosurgery for Brain Metastasis

• Local control Rates of 73 to 94%
• Risk of radiation necrosis of 5 to 10%

Better than whole brain if single lesion and good performance patient in the RTOG 95-08 Trial