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Disorders
We Treat
 Brain Metastases
Metastases to the brain from a primary tumor that
is outside the central nervous system (CNS) are more common than primary
tumors of the brain. The most common primary tumors that metastasize to
the brain are lung, breast, melanoma, and kidney. Metastases to the brain
are usually multiple, but solitary metastases may also occur. Brain involvement
can occur with cancers of the nasopharyngeal region by direct extension
along the cranial nerves or through the foramina at the base of the skull.
Metastatic meningeal involvement can also occur, especially with leukemia,
lymphoma, small cell lung cancer, breast cancer, and some primary CNS
tumors (such as medulloblastoma and ependymal gliomas).
Certainty of Diagnosis: A
mass or tumor that is in the brain should not be assumed to be a metastasis
just because a patient has had a previous cancer; such an assumption could
result in overlooking appropriate treatment of a curable tumor. Primary
brain tumors rarely spread to other areas of the body, but they can spread
to other parts of the brain and to the spinal axis.
Diagnosis: The diagnosis
of brain metastases in cancer patients is based on patient history, neurologic
examination, and diagnostic radiologic procedures. Patients may describe
headaches, focal weakness, seizures, loss of sensation, or difficulties
with gait or balance. Often, however, patients are brought by family members
or friends who have noticed lethargy, emotional lability, or personality
change. Physical examination may demonstrate objective neurologic signs,
but often only minor cognitive signs are present.
Radiology: Magnetic resonance
imaging is the most sensitive and specific diagnostic tests currently
available. The MRI shows metastases that may be missed by CT (CAT) scanning.
Treatment: For single metastases,
surgery or radiosurgery are options for treatment. The decision is based
upon the size, location of the tumor, and the rate of progression of the
symptoms. For surgery, whole brain radiotherapy is usually given afterwards.
For radiosurgery, whole brain radiotherapy may or may not be recommended.
For multiple metastases, whole brain radiotherapy followed by stereotactic
radiosurgical "boost" has shown higher rates of "intracranial
control" when compared to whole brain radiotherapy alone.
The results of treatment are a function
of the patient's age, "performance status," status of the extracranial
tumor (growing vs. controlled), and the presence or absence of other metastases
elsewhere in the body. For the younger patient with limited extracranial
disease and high performance status, the most aggressive treatment should
be considered.
The decisions related to treatment for
the brain metastases depend upon the complete understanding of the competing
risks vs. benefits for the different treatments. Options for brain metastasis
treatment may include surgery, radiosurgery and gamma knife. FSR (fractionated
stereotactic radiosurgery) for brain metastases is an important option
for treatment. The important considerations include the size and rate
of growth of the brain metastasis, as well as the progression of any symptoms.
Metastases to the brain from a primary
tumor that is outside the central nervous system (CNS) are more common
than primary tumors of the brain. Metastases to the brain are usually
multiple, but solitary metastases may also occur. Approximately 1 in 4
patients with cancer will develop tumors that spread to the central nervous
system (CNS), usually through the blood stream to the brain. The most
common primary tumors that metastasize to the brain are lung, breast,
melanoma, and colon, however, almost any cancer has this potential.
Metastatic tumors typically arise where
the white and gray matter of the brain meet. The symptoms depend upon
the function of the affected part of the brain, but also can include headache
or seizures -- or no symptoms at all, when first detected.
The results of treatment for metastatic
brain tumors was once considered to be bleak. It has been convincingly
shown, however, that aggressive surgical management combined with radiation
treatment can lead to a substantially better outcome in some patients,
both in terms of survival and quality of life. Control of a single metastasis
to the head is better when surgery is combined with radiation therapy,
in comparison to either treatment alone. The benefit of aggressive management
of multiple brain metastases is less clear, yet depending on the particular
patient, surgery is sometimes considered when there are life-threatening
tumors, especially if the patient otherwise is in good condition.
Radiosurgery and gamma knife are important
options for patients with small numbers of brain metastases and who are
otherwise in good physical condition.
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