Radiation Oncology

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Central Nervous System (Brain) Tumors

The central nervous system is comprised of the brain and spinal cord.  Approximately 17,000 brain tumors are diagnosed each year. Brain tumors may be benign or malignant but due to the confined nature of the skull even tumors that are benign may cause problems secondary to increased pressure from a growing mass. 

Tumors that arise from brain tissue are referred to as primary brain tumors.   They are classified by the cell type and grade.  The most common tumors are astrocytomas which are also called glioblastoma multiforme if they are high grade.  Other common malignant tumors in adults include gliomas, meningiomas, ependymomas and oligodendrogliomas. Tumors are graded from  1 to 4 with 4 being the most aggressive.

Cancer that began in another site of the body which spreads to the brain is termed metastatic. Lung cancer is by far the most common primary site to spread to the brain although nearly all types of cancer have the potential to metastasis to the brain. 

Treatment for primary brain tumors depends on several factors including the size of the tumor, its location, its size ,as well as the patients age and overall health.  Surgery is usually performed as it is the most effective primary treatment and allows for the examination of the tissue specimen to determine the tumor type.  Surgery is performed by a neurosurgeon through an operation called a craniotomy.  In general every attempt is made to resect the entire tumor however if this is not possible a biopsy to obtain a small amount of tissue for examination may be performed.

External beam radiation therapy is generally given following surgical resection to the area of resection to reduce the risk of tumor recurrence.  Treatment is highly individualized and 3D conformal techniques are used to reduce the dose to the surrounding healthy brain tissue.  Stereotactic radiosurgery which pinpoints the radiation to a small region is sometimes used as a boost or as single treatment following surgery or in lieu of a traditional neurosurgical resection. 

Stereotactic radiosurgery's role in the treatment of primary brain tumors and metastatic lesions is currently under clinical evaluation although the preliminary experience with this technology has been very promising.  Whether this type of treatment is appropriate for you is a complex issue that should be discussed with your doctors.

Chemotherapy is also sometimes recommended for certain brain tumors.  In addition to standard chemotherapy given through the veins small wafers which deposit a chemotherapeutic agent may be implanted at the time of surgery. There has been great progress made in the treatment of brain tumors although further advances are needed.