Second Advanced Radiation Therapy System Arrives at Marin Cancer Institute
The most powerful and versatile cancer treatment technology available today, the Trilogy medical linear accelerator, has begun treating cancer patients with image-guided radiation therapy at the Marin Cancer Institute, a program of Marin General Hospital.
On July 10, physicians began using the $3 million Trilogy image-guided radiation therapy system from Varian Medical Systems to treat a variety of cancerous tumors of the brain and body.
Trilogy joins a $2.5 million linear accelerator installed last July at the Marin Cancer Institute. Both Varian machines are high-powered medical linear accelerators (linacs), which rotate around the patient to deliver radiation treatments from nearly any angle. The Trilogy system also incorporates a multi-leaf collimator for shaping the radiation beam to match the three-dimensional shape of the tumor being targeted, and an On-Board Imager™ device for fast, accurate, real-time tumor tracking and automated patient positioning.
In addition to delivering conventional forms of radiation therapy, the Trilogy system can be used stereotactically to treat very small lesions quickly and with unprecedented precision. The benefits of stereotactic approaches, in which the beam is directed in three dimensions to deliver a dose of radiation to a defined area of the body, are generally realized when treating smaller lesions.
“Better diagnostic tools have made it possible for us to see tumors much earlier, when they’re still very small,” said Chun Li, Ph.D., the institute’s medical physicist. “Stereotactic approaches are generally most appropriate for small lesions and early metastases, and so are likely to play a much larger role in radiation oncology. Our doctors can now offer patients the full spectrum of treatments and choose the most appropriate treatment modality for their particular form of cancer, whether in the body or the brain.”A radiation therapy system of the sophistication of Trilogy is unusual at a community-based hospital. Most other hospitals employing Trilogy are teaching and research hospitals in large urban areas. In the Bay Area, Trilogy machines are in use in two centers in San Francisco and two in Palo Alto. MGH has the only Trilogy between San Francisco and Portland, Ore.
The Trilogy system incorporates special accessories for Image-Guided Radiation Therapy (IGRT). These improve the treatment precision, which means that higher radiation doses can be delivered directly to tumor cells, while healthy, normal tissues are better protected. In part this is because Trilogy’s automated, robotic X-ray imaging tool, the On-Board Imager, makes it possible for the radiation therapist to target and track tumors more accurately on a daily basis.
Trilogy is superior to older-generation radiation therapy tools in that it permits physicians to eradicate tumors with unparalleled accuracy and greater efficiency, promising better treatment outcomes. Patients also benefit from short treatment times, which significantly improve their comfort.
“This is the best radiation therapy system available,” emphasized Dr. Li. “With Trilogy, we are able to treat certain crucial areas of the body with the same pinpoint precision as surgery without compromising surrounding tissue. Our radiation oncologists are working together with neurosurgeons and other members of our outstanding MCI team to deliver this care.”Trilogy and the other new medical linear accelerator are treating cancer patients at the Marin Cancer Institute, 1350 S. Eliseo Drive, Greenbrae.
“Radiation therapy is used today in more than half of all cancer treatments due to its unique clinical advantages, and it is becoming steadily more effective with new technologies that permit ultra-precise dose delivery,” said Dr. Lloyd Miyawaki, the institute’s Medical Director. “Using the Trilogy system, we have the potential to substantially improve cancer treatment outcomes by doing a better job protecting healthy tissue while delivering more powerful doses to the tumor.”