Stereotactic radiosurgery (SRS)

Unlike its name implies, radiosurgery does not involve surgery. In one, or just a few treatments, known as fractions, precisely targeted, high doses of radiation are delivered to small brain tumors. The goal of stereotactic radiosurgery is to ablate, or destroy, the tumor(s) while sparing surrounding healthy tissue. Stereotactic radiosurgery may allow doctors to reach tumors deep inside the cranium (skull) without the risks of surgery. Radiation beams are delivered to the target from different angles based on 3-D images pinpointing the tumor’s exact location. The treatments require no incision and cause little discomfort and few of the risks typically associated with surgery.

The type of stereotactic treatment performed depends on the particulars of each patient’s cancer type and location. Our radiation oncologists perform stereotactic treatment using a variety of technologies, including TrueBeam™, Varian's Trilogy® and the CyberKnife® robotic radiosurgery system. This treatment is often recommended over conventional radiation therapy for its ability to treat small tumors in a shorter period of time.

CyberKnife® Robotic Radiosurgery System

CyberKnife is a non-invasive option for patients who have inoperable or surgically complex tumors, or who may be looking for an alternative to surgery. The CyberKnife system’s continual image guidance software allows us to deliver targeted doses of radiation, while automatically correcting for tumor movement. Since radiation beams adjust in real-time to the patient’s breathing cycle, the system is designed to cause less damage to surrounding healthy tissue.

Prior to the procedure, a high-resolution CT scan determines the size, shape and location of the tumor. The image data is then digitally transferred to the CyberKnife System’s workstation, where we plan treatment to match the desired radiation dose to the tumor location. Once treatment planning is complete, the patient is positioned on a cushioned table and the system’s computer-controlled robot slowly moves around the table, targeting radiation to the tumor from various angles, which helps to spare surrounding healthy tissue.

The system’s software allows us to track the tumor and continually adjust the radiation treatment to account for patient or tumor movement. Each treatment session lasts between 30 to 90 minutes for one to five days, depending on the location and type of tumor being treated. Patients can typically complete treatment in one to five days versus several weeks for traditional radiation therapy.


TrueBeam is an advanced image-guided radiation therapy (IGRT) system used to treat cancer with speed and accuracy while avoiding healthy tissues and organs. TrueBeam was designed for complex cases of cancer of the lung, breast, stomach and brain. It also can be used for cancers of the liver and prostate, along with other cancers treated with radiation therapy.  

TrueBeam rotates around your body to deliver radiation therapy from nearly any angle. The system provides real-time imaging, which allows your doctor to direct higher doses of radiation with greater accuracy. At the same time, TrueBeam’s respiratory gating technology gives your doctor the ability to synchronize radiation beams with your breathing. For example, doctors can treat a moving lung tumor as if it were standing still. Respiratory gating also protects nearby organs and healthy tissues from unnecessary radiation.

Varian Trilogy®

The Trilogy radiation therapy system may be used to provide intensity modulated radiation therapy (IMRT), image guided radiation therapy (IGRT), stereotactic radiosurgery (SRS) and fractionated stereotactic radiation therapy—all from one machine. The technology’s real-time imaging gives us up-to-the-second diagnostic data so we can monitor tumor motion during your breast cancer radiation therapy, provide high doses of extremely targeted radiation therapy and avoid harm to healthy tissues that surround breast tumors.

In addition, Trilogy includes respiratory gating capabilities, which enables us to deliver optimal doses of radiation to breast tumors with utmost accuracy. The Trilogy treatment system senses and accounts for motion as you breathe in and out, helping us to target the breast tumor and protect organs that are close to the breasts, including your heart, from receiving unnecessary radiation.