As Metastatic Brain Tumor Rates Rise, Targeted Therapies Offer a Better Treatment Alternative

In In The News by Barbara Jacoby

Up to 45% of all cancer patients develop brain metastases, tumors that spread to the brain from cancers located elsewhere in the body. As the number of patients affected by metastatic brain tumors grows, targeted treatment options, like the Gamma Knife™ radiosurgery, may offer better tumor control and symptom management.

Metastatic brain tumors are some of the most common types of tumors that can occur in the brain(1). As many as 45% of all cancer patients develop brain metastases(2), with an estimated that up to 200,000 people develop metastatic brain tumors each year in the United States(3). For people with metastatic brain tumors, targeted therapy, like stereotactic radiosurgery using the Gamma Knife™ at San Diego Gamma Knife Center (®, offers effective treatment for metastatic brain tumors while helping patients to live as normally as possible.

Metastatic brain tumors, also known as “brain mets”, form when cancerous cells from a tumor located elsewhere in the body, such as in lung or breast, break off from the original, or primary, tumor and travel through the bloodstream. Eventually, these circulating cancer cells cross the blood-brain barrier and settle in the brain(3). Once there, a new brain tumor is formed. Up to 45% of cancer patients develop these types of brain tumors(3).

While it is possible for any type of primary cancer to influence the development of brain mets, some cancers are more likely to cause metastases in the brain than others. As many as 25% of patients with lung cancer will develop brain mets(3). Other forms of cancer, including melanoma and breast, colon, and kidney cancers all frequently promote the formation of brain metastases.

“Since intracranial metastases occur with relatively high frequency and come from common tumors such as, lung cancer and breast cancer, it is important that patients seek effective and appropriate treatment as soon as possible,” said Kenneth Shimizu, M.D., Radiation Oncologist at San Diego Gamma Knife Center.  “Delay and treatment can result in stroke-like symptoms with permanent neurologic damage.”

Traditionally, treatment for brain mets has included invasive surgery to remove tumors or whole brain radiation therapy (WBRT). However, both of these options come with side effects that are often debilitating and, for some types of brain mets, do not significantly increase life expectancy or quality of life for the patient(3, 4). In many cases, despite efforts to best control the spread of cancerous cells in the brain using these types of treatments, tumors often grow back(4).

Due, in part, to increased interest in targeted treatment approaches, treatment options like the Gamma Knife™ are gaining popularity among both healthcare professionals and patients. This advanced radiosurgical system delivers a concentrated dose of radiation directly to metastatic brain tumors(5). It is minimally invasive, so patients are able to avoid complications associated with traditional surgical interventions. Also, because radiation is not delivered to the entire brain, like with WBRT, patients avoid many of the serious side effects that can occur, including dementia and a decline in physical functioning(2).

Up to 94% of patients who receive treatment using the Gamma Knife™ are able to achieve therapeutic results, including tumor control(5). In most cases, this is possible after having just one treatment. This new type of therapy is offered at progressive healthcare facilities nationwide, including the SDGKC.

“Historically, when treating patient with brain metastases, we were only able to use whole brain radiotherapy which would not only treat the metastases but also the normal brain tissue resulting in potential significant side effects, including short-term memory loss,” said Dr. Shimizu. He explained that over time, there has been the development of stereotactic radiosurgery (SRS) which targets the tumors and spares the normal brain.  With the advent of the Gamma Knife Perfexion unit, targeting has become more precise than at the other treatment platform with less dose to the normal brain.  The targeting precision allows treatment of a very high dose with little risk of damage to the normal brain and with more than 90% tumor control.

About San Diego Gamma Knife Center®:

Since its opening, the San Diego Gamma Knife Center has treated over 4,000 patients with various brain disorders from around the world. The facility is equipped to provide advanced radiosurgical treatment for a variety of conditions, including metastatic brain tumors, primary brain tumors, arteriovenous malformations, and functional disorders such as trigeminal neuralgia and cluster headaches.

On the campus of Scripps Memorial Hospital in La Jolla, California, the Center offers the use of its facilities to the neurosurgeons and radiation oncologists in Southern California. To learn more about the San Diego Gamma Knife Center, please visit


  1. “Metastatic Brain Tumors.” AANS. N.p., n.d. Web.
  2. “Brain Metastasis.” Practice Essentials, Background, Pathophysiology. N.p., 14 Nov. 2016. Web. 16 May 2017.
  3. Cancer Resources from OncoLink | Treatment, Research, Coping, Clinical Trials, Prevention. “All About Brain Metastases.” OncoLink. N.p., n.d. Web. 16 May 2017.
  4. “Current and Emerging Treatments for Brain Metastases.” Current and Emerging Treatments for Brain Metastases | Cancer Network. N.p., 15 Apr. 2015. Web. 16 May 2017.
  5. “GAMMA KNIFE® SURGERY.” Gamma Knife® Surgery. N.p., n.d. Web. 16 May 2017.