Trilogy® Radiotherapy System

Non-invasive treatment option for tumors

Trilogy is a revolutionary image-guided radiotherapy (IGRT) system offering patients a non-invasive option for treating tumors in the brain or other critical anatomy, termed intracranial and extracranial tumors. The Trilogy system combines diagnostic-quality imaging and treatment technologies into one efficient tool, allowing physicians to treat with any modality of external-beam radiation therapy using one machine. The Trilogy system can be used for conformal and Intensity-modulated radiotherapy (IMRT) delivered in daily small doses over a period of weeks. It can also treat small lesions using stereotactic radiosurgery (SRS), delivered in a single treatment, or stereotactic radiotherapy delivered over a period of a few days.

To enhance treatment precision, the Trilogy accelerator is equipped with an on-board imaging device for fast, accurate, real-time tumor tracking, a multi-leaf collimator which shapes beams to match the tumor shape, and an automated patient positioning system, making image-guided radiotherapy a reality. Cone-Beam Computed Tomography (CT) technology allows physicians the ability to see a three-dimensional (3D) image of the tumor and adapt the treatment plan to maximize accuracy and effectiveness.

Trilogy can be used to deliver the widest range of external beam radiotherapies:

• 3D conformal radiotherapy (3D-CRT) – shapes the radiation beams to match the shape and contours of the tumor.


• Intensity-modulated radiotherapy (IMRT) – shapes the radiation dose within the beams to avoid critical organs.


• Stereotactic radiosurgery (SRS) – precisely focuses multiple converging beams to deliver radiation treatment in single or multiple sessions.


• Intensity-modulated radiosurgery (IMRS) – combines IMRT and SRS for highly-accurate neurosurgical treatments or for treating tumors outside the brain, called extracranial treatments.

Linear Accelerator

The main element of Trilogy’s fully-robotic therapy system is the linear accelerator. The accelerator rotates around the patient delivering precisely-shaped radiation beams from a wide variety of angles. Trilogy can target cancer treatment with sub-millimeter accuracy Patients receive faster, more effective treatment, and reduced radiation volume, minimizing side-effects and complications while enhancing their quality of life. This system allows more exact treatments to be delivered, even when treating tumors that lie extremely close to critical anatomy like the heart, spinal cord, lung, rectum or salivary glands.

Respiratory Gating System

The respiratory gating system, also a component of Trilogy, automatically turns the beam off and on to compensate for breathing motion during treatment. This keeps the radiation beam focused on the tumor, and further protects normal healthy tissues.

ExacTrac® SABR Knife

An accessory to the Trilogy, the ExacTrac® Stereotactic Ablative Brain/Body Radiation (SABR Knife) provides one of the most advanced and fastest stereotactic radiosurgery (SRS) treatments. SABR Knife’s frameless, image-guided radiation therapy (IGRT) system provides greater accuracy in targeting tumors, allowing us to treat a greater range of conditions. Read a complete description of the SABR Knife technology.

California Pacific Medical Center Foundation

Through the generosity of a grateful patient and the California Pacific Medical Center Foundation, we are able to provide the Trilogy system’s advanced cancer treatment technology to the many patients we serve. Private support has served as a catalyst for many of California Pacific Medical Center’s most critical initiatives -- researching the most up-to-date treatments, funding the most sophisticated equipment available, and providing a wide array of innovative and much-needed patient programs and services. To learn more about how you can help California Pacific Medical Center, please call 415-600-4403.