Stereotactic Radiation Therapy and Gamma Knife Radiosurgery
Stereotactic radiosurgery (SRS) is exciting technology combining the clinical expertise of the radiation oncologist with several technological advancements available in radiation oncology today. Physicians and patients are most familiar with radiation therapy delivered as external beam therapy in which relatively small amounts of radiation are precisely delivered to a cancer each day for several weeks. In contrast, SRS is a radiation therapy technique that delivers a single high dose of radiation to a cancer, as well as some benign diseases, with extreme precision. “Stereotactic” refers to the computerized 3-dimensional coordinate system used to locate a cancer within the brain or body. Contrary to the use of the term surgery in its name, radiosurgery is not an operation. Instead, SRS kills cancer through a non-invasive procedure performed in an outpatient setting without anesthesia.
Benign and Malignant Diseases Treated with Radiosurgery
- Gliomas
- Metastatic Brain Tumors
- Pituitary Tumors
- Meningiomas
- Craniopharyngiomas
- Acoustic neuromas
- Lung Cancer
- Liver Cancer
- Arteriovenous Abnormalities
- Hemangiomas
- Trigeminal Neuralgia
- Metastases from various cancers
- Spinal Cord Tumors
Linear Accelerator Based SRS
A linear accelerator is typically used to deliver conventional external beam radiation therapy. However, with the appropriate technical modifications and enhanced treatment planning capabilities, a state-of-the-art linear accelerator can also be used for SRS. Linear accelerator based SRS is widely used for malignant and benign diseases in both the brain and in the body. With careful patient immobilization and accurate tumor localization utilizing image guided radiation therapy (IGRT), precise radiation can be delivered with a stereotactic technique. SRS allows treatment of small tumors in areas of the body most sensitive to radiation.
Gamma Knife®
A Gamma Knife® is a specialized stereotactic radiation treatment device designed to treat small brain tumors, benign and malignant, with pinpoint accuracy. Although a knife is not involved, the Gamma Knife® directs over 200 beams of radiation to converge on the tumor with knife-like precision. The overall effect is to deliver a very high radiation dose to the tumor in a single treatment while sparing the healthy parts of the brain from radiation.
Advantages of SRS
The primary advantage of SRS is that it gives the physician the ability to locate and treat small tumors with great precision. As a result of sophisticated tumor localization technology, a single large dose of radiation can be safely delivered, eliminating the need for weeks of radiation therapy. In addition, patients may also experience fewer treatment-related side effects with SRS because normal healthy tissue is largely spared the effects of radiation. It is important to note that not all cancer patients are candidates for SRS. Tumor size is an important criterion for patient selection. With the current SRS technology, only tumors less than 4 cm in size can be successfully treated.
ROS’ Stereotactic Radiosurgery Program
ROS physicians are trained in the safe and effective use of SRS. Currently, the procedure is performed at several ROS centers in the metropolitan Atlanta area.
ROS and Gamma Knife® at Saint Joseph’s Hospital of Atlanta
ROS physicians, Nancy Wiggers, M.D. and Peter Possert, M.D. use Gamma Knife® technology to treat patients with various cancers and benign conditions involving the brain at Saint Joseph’s Hospital of Atlanta. Enhanced Gamma Knife® technology known as Perfexion™ is available to patients in need of brain SRS. The marvels of Perfexion™ technology enhance Drs. Wiggers’ and Possert’s ability to treat previously inaccessible brain tumors with greater efficiency and precision.
