Question and Answer about Stereotactic Radiosurgery: No Incision Brain Tumor Treatment for Metastatic Cancer
Barbara Lazio, M.D., is a board certified neurosurgeon with special training in brain tumor treatment and Stereotactic Radiosurgery. Prior to joining the Providence Medical Group – Southwest Washington Neurosurgery’s Brain & Spine Center, she practiced in North Carolina as Associate Professor of Neurosurgery at East Carolina University, leading the installation and clinical launch of the Gamma Knife Program.
Can you begin by telling us what a brain metastasis is?
Dr. Lazio: Metastasis means a cancerous tumor has spread to other sites within the body. Brain metastases are tumors occurring in the brain but originating from other organs, commonly lung or breast. About 15- 20% of all cancers diagnosed will spread to the brain. The cancers most likely to spread to the brain are lung, breast, melanoma, renal, and colon cancers. Cancers less likely to metastasize to the brain are prostate, cervical and ovarian.
How does a person learn they have a metastatic brain tumor and what are some symptoms?
Dr. Lazio: If you have been diagnosed with cancer, your oncologist may recommend a brain CT or MRI to rule out brain metastasis, either prior to treatment or in response to symptoms such as headaches, new balance disturbance, weakness or seizure.
Sometimes the brain is the first indication that a person has cancer. Symptoms again include new or unusual headaches, weakness, especially one-sided, that come on gradually over days or weeks. Other symptoms are seizure, loss of balance or change in behavior.
I have heard about Gamma Knife, CyberKnife and proton beam therapy for brain metastasis. What is the difference?
Gamma Knife and CyberKnife are brand names for machines that perform a single type of treatment called Stereotactic Radiosurgery. Stereotactic Radiosurgery is a non-invasive, one-time, highly-precise (like a surgeon’s knife) delivery of high-dose radiation to an abnormality in the brain. Small, multiple or deep brain metastases are frequently treated with Stereotactic Radiosurgery instead of open brain surgery or standard radiation. Stereotactic Radiosurgery is mostly used for metastatic brain tumors and benign primary tumors such as meningiomas and schwannomas. The nature of most malignant primary tumors (also called brain cancer, or tumors originating in the brain) is that they are less focal, more widely invasive and therefore difficult to target with this therapy, in most cases.
All types of Stereotactic Radiosurgery involve taking high-resolution images of the brain and then precisely targeting the tumor using a special computer program. This technology helps us target the tumor very accurately, while limiting the dose to normal tissue to small amounts.
Gamma Knife uses Gamma Rays. Cyberknife, Varian, and several other kinds of Stereotactic Radiosurgery use a linear accelator, which is closer to x-ray radiation. Proton beam therapy uses protons – but the way the technology works for the patient is very similar.
What can I expect the day of treatment?
The treatment is done as an outpatient in most cases. Some technology, such as Gamma Knife, require a frame to be placed on the head to keep the head completely still during treatment. This is done with local anesthetic to the scalp and usually some mild sedation. An MRI or CT is done with the frame on the person’s head to keep it very still.
After the doctors certified in Stereotactic Radiosurgery review the images and develop an optimal treatment plan on the computer, the actual treatment takes place. The treatment itself usually lasts between 15 and 60 minutes. Patients cannot see or feel the radiation beams as they intersect on the tumor(s). Some Stereotactic Radiosurgery is done without a frame, but require either a mask and a live tracking device, or frequent x-rays and adjustment of the beams to maintain treatment accuracy. Either way, the technology helps us to ensure the treatment is very accurate, in order to destroy the cancer while protecting healthy brain tissue.
Does the tumor disappear immediately?
Like other radiation procedures, the tumors will shrink or disappear gradually over weeks to months as the cancer cells damaged by the radiation die. Usually by six weeks after treatment the tumors have shrunk.
Is this a curative or palliative treatment?
Technically, cancer that has spread to the brain is stage 4 cancer, and not considered curable. On the other hand, this treatment can often prolong someone’s life significantly and, in some cases – usually when a person has one small tumor – the metastasis can disappear and not come back as a result of the treatment.
Although this stage of cancer is not generally considered curable, I hesitate to use the term ‘palliative care’ since many people associate the term only with hospice treatment or treatments that give comfort. In many cases, this treatment can allow individuals to live years beyond what would be possible without it, even if they are never pronounced cancer free.
Will I lose my hair?
It is rare for a person to lose hair after Stereotactic Radiosurgery. However, in tumors close to the surface, there may be some mild hair loss immediately adjacent to the tumor site which is usually temporary.
When can I return to normal activities?
Most people return to normal living activities by one to three days after Stereotactic Radiosurgery. Since there is no incision, there are few if any restrictions on activity.
Every treatment option, including Stereotactic Radiosurgery, has pros and cons, including potential side-effects. However, this treatment can be very effective in the right cases. I suggest speaking with members of your cancer care team about whether you are a good candidate for this treatment.
