Treating brain tumors with stereotactic radiosurgery
August 12, 2020
When it comes to brain tumors, precision and potency is key to safe, successful treatment. Brain tumors are often found in critical locations for our everyday function. This makes radiation delivery a complex art.
Stereotactic radiosurgery is an elegant solution that allows us to treat benign and malignant brain tumors with precision, potency, and safety beyond traditional forms of radiation. It is based on the principle of nearly 200 pinpoint beams coming from all angles, which converge on the tumor and deliver minimal radiation to adjacent healthy tissue.
Brain tumors might begin directly in the central nervous system (CNS), while others are a result of cancer in the body that has spread to the brain (metastatic tumors). A team of specialists – including radiation oncologists, neurosurgeons, neurotologists, and neuroradiologists with expertise in each of the types of tumors – must work together in treating patients with stereotactic radiosurgery, such as with the Gamma Knife® and CyberKnife® systems.
Advances in technology with modern imaging, radiation machines, and extensive clinical experience help our physicians develop highly customized treatment plans for each patient. This precision medicine approach gives patients customized care that can result in fewer visits and improved outcomes in their cancer care.
Harold C. Simmons Comprehensive Cancer Center is one of only 49 NCI-designed Comprehensive Cancer Centers in the U.S. We have some of the most high-tech radiation machines in the country, including the first Gamma Knife Icon in North Texas.
Advanced radiation technology for brain tumors
Stereotactic radiosurgery is a form of radiation therapy that delivers high doses of radiation within one to five treatments. It can be delivered with multiple treatment machines including the Gamma Knife, CyberKnife, and modern linear accelerators.
At UT Southwestern we have all of the machines available. This allows us to select not only the best treatment but also the best technology for each individual patient. The treatment can be delivered with either a stereotactic head frame for a minimally invasive approach or, with the Gamma Knife Icon, without a frame and with a mask for a completely non-invasive experience.
Despite its name, there is no “knife” or cutting when using the Gamma Knife. Rather, it is a machine developed with 192 pinpoint sources of radiation that come from all angles and converge on the tumor. Traditionally, this was only delivered with a head frame that is attached to the skull via four pins.
This is an excellent, minimally invasive choice for tumors that are within millimeters of critical nerves, such as those responsible for vision. The latest iteration of the machine has expanded its capability with the option of using a mask rather than the head frame. This has allowed us to treat more patients who may have not been a candidate for the brain-sparing benefits of this technology, such as those who would otherwise receive whole-brain radiation.
CyberKnife, like the Gamma Knife, does not involve any cutting and is a non-invasive method for delivering stereotactic radiotherapy. It is treatment delivered with a robotic radiation machine that moves to many angles, delivering focused radiation while wearing a mask. Throughout the treatment, the machine continuously monitors the patient’s position and adjusts for millimeter movements on the fly.
Both the CyberKnife and Gamma Knife are outpatient procedures. Patients go home the same day with no concern for radiation exposure to family and minimal limitations on activities.
Advanced technology, unparalleled expertise
When you are diagnosed with a brain tumor, you want your treatment to be as precise and customized as possible. Dr. Zabi Wardak and the Radiation Oncology Team at UT Southwestern's Simmons Cancer Center deliver some of the most advanced tumor treatments available in the world.
Surgery and chemotherapy for brain cancer
Stereotactic radiosurgery is often paired with surgery in precision medicine. Doctors can remove larger tumors and understand the tumor biology to form a better care plan. There are two types of surgery – endoscopic and open – with varying levels of invasiveness.
Surgery can be successful, and no further treatment may be needed. However, sometimes tumors are too close to critical structures, which makes complete surgical removal impossible. In those cases, following up with stereotactic radiosurgery and/or chemotherapy can destroy remaining cancer cells.
Chemotherapy is a medical treatment that targets and destroys rapidly dividing cancer cells. For patients with metastatic cancer, chemotherapy may be a first line of treatment to stop the cancer from growing. Then radiation can be used to treat tumors within the brain and other parts of the body.
The goals with any of these treatments are to improve patient outcomes and limit negative side effects. While not all treatments are suited for each patient, the improvements in radiation technologies can provide the aggressive, precise treatment they need.
The future of brain cancer treatment
Research and technological advancements are among the most important factors in treating brain tumors and CNS cancers: the more options, the more personalized treatment we can offer.
My colleagues and I are continuing to research the effectiveness of stereotactic radiosurgery in removing brain metastases and tumors. We welcome patients in our clinical trials and research to help us learn more about the best treatments.