UC Davis Cancer Center first in Northern California to fight cancer with tomotherapy

New technology is part of a $7 million radiation oncology expansion

UC Davis Cancer Center is the first facility in Northern California to acquire tomotherapy technology to treat patients with cancer, center officials announced this week. The $3 million machine, representing the latest in radiation treatment technology, is already in operation. Only 55 of the machines are in use nationwide.

The investment in new technology makes UC Davis Cancer Center's Radiation Oncology Clinic the best-equipped facility in Northern California and among the most sophisticated in the country.

"We now offer our patients more treatment options than any other cancer center in our region," said Srinivasan Vijayakumar, professor and chair of radiation oncology at UC Davis.

The new technology is part of an ambitious, four-year $7 million expansion of the Radiation Oncology Clinic and Department of Radiation Oncology spearheaded by Vijayakumar, who joined UC Davis from the University of Chicago in 2002. The expansion includes the recruitment of five new radiation oncology faculty physicians and physicists, along with completion of a 7,000-square-foot addition to the Radiation Oncology Clinic, located at 4501 X Street on the UC Davis Medical Center campus.

The expansion will allow UC Davis Cancer Center to better serve the region's rapidly growing population.

The field of radiation oncology has witnessed rapid progress in recent decades, as technological advances have made it possible for physicians to deliver increasingly targeted and powerful doses of radiation to treat cancers.

The 9,000-pound tomotherapy machine is at the cutting edge of this trend. Tomotherapy addresses an important shortcoming inherent in conventional radiation treatment. Traditionally, a physician obtains images of a tumor days or weeks before radiation therapy starts, and uses these images to plan treatment. But by the time treatment starts, the cancer may have grown or changed shape, or the patient's weight may have changed, causing a shift in tumor position.

"This uncertainty about the tumor's exact position has always meant calculating a 'margin of error' and treating a zone around the tumor that is likely to include some healthy tissue. To avoid applying excessive radiation doses to this surrounding tissue, radiation oncologists have had to use lower-than-desired doses to treat the tumor," Vijayakumar said.

Tomotherapy solves the problem by marrying a high-resolution CT scanner to a sophisticated linear accelerator, allowing doctors to visualize a tumor and apply radiation at the same time, with pinpoint accuracy. This enhanced precision enables doctors to use tighter margins and higher, more effective radiation doses.

In addition, tomotherapy employs a linear accelerator that rotates in a 360-degree spiral around the patient, delivering radiation to the tumor from all directions. Traditional linear accelerators deliver radiation beams from just a handful of angles.

Since the technology first reached the market in 2002, six other tomotherapy systems have been acquired on the West Coast: one in Bellingham, Washington, and five in Southern California. UC Davis has the only tomotherapy unit in California north of Los Angeles County. Tomotherapy systems are marketed by TomoTherapy, Inc., in Madison, Wisconsin.

Other companies are introducing competing systems that take a different approach to address the time lag between imaging and radiation treatment.

One such system, marketed by Elekta, a Swedish company, was installed at UC Davis Cancer Center last summer. Known as Synergy, the system combines an advanced linear accelerator with three-dimensional x-ray technology. The linear accelerator in the Synergy system doesn't rotate around the patient. But unlike tomotherapy, the Synergy machine can deliver a range of radiation energy levels tailored to a tumor's location and shape. A third, advanced image-guided radiation therapy system is being installed at UC Davis Cancer Center this summer.

UC Davis Cancer Center also offers patients two technologies for cranial radiosurgery: a gamma knife (Leksell) and a micro-multileaf collimator (BrainLAB). The BrainLAB system can treat larger, irregular lesions, while the Leksell gamma knife can treat smaller tumors. UC Davis is the only institution in the Sacramento region and one of a small number in the country to offer both technologies.

"No single technology is best for every patient," Vijayakumar said. "But by having more of the latest tools at our disposal, we are able to offer patients more choices to fight their disease."

Vijayakumar, one of the nation's leading radiation oncologists, is the author of "An Oncologist's View of Prostate Cancer: Understanding the Facts, Sorting through the Options," a layperson's guide to prostate cancer treatment.