Radiation Oncology at Celilo Cancer Center

Radiation oncology is the medical use of ionizing radiation as part of cancer treatment to control malignant cells. To spare normal tissues, shaped radiation beams are aimed from several angles to intersect at the tumor, providing a much larger dose there than in the surrounding, healthy tissue.

Celilo Cancer Center employs a radiation therapy technology called intensity modulated radiation therapy (IMRT). Our Elekta Synergy linear accelerator combines CT scanning with IMRT to help Celilo’s radiation specialists even more precisely and effectively deliver the advanced IMRT technology.

The Synergy linear accelerator’s CT technology provides “3-D image-guided” (IGRT) capabilities that enable higher doses of radiation to be delivered more precisely to cancer tumors. This increases the daily accuracy of treatment and reduces the effect on surrounding tissue. IGRT allows staff to more efficiently and effectively adjust for the body and organ movements that can occur during treatment.


For many women diagnosed with breast cancer, radiation therapy is an effective, and far less physically and emotionally taxing, alternative to mastectomy. Several studies have shown that treatment combining tumor removal with external radiation therapy has produced the same cure rate as total breast removal.

Yet, despite the obvious advantages of radiation treatment, many women still choose to have mastectomies – often because of the long treatment regimen required for external radiation treatment.

At Celilo, however, breast cancer patients may benefit from a procedure called brachytherapy, which dramatically shortens the radiation therapy process to only one week, compared with the four weeks required for external radiation therapy. The procedure enables radiation specialists to deliver higher doses of radiation to very defined areas of the breast without affecting surrounding tissue.

Meet Keith Stelzer, MD, PhD

Dr. Keith Stelzer is a leading expert in the application of intensity modulated radiation therapy (IMRT) the technology used at Celilo that shapes radiation beams more precisely to spare surrounding tissue.

Dr. Stelzer graduated from the University of California Davis in 1981. He received his Ph.D. in toxicology from the University of Kansas Medical Center in 1985 and his medical degree from the University of California, Los Angeles, in 1989. Dr. Stelzer completed an internal medicine internship at St. Vincent Hospital in Portland and a radiation oncology residency at the University of Washington in Seattle, where he was chief resident from 1992 to 1993.

Dr. Stelzer was associate professor in the Radiation Oncology and Neurological Surgery departments at the University of Washington, and he continues as a clinical associate professor of Radiation Oncology at UW Medical Center.

Board certified by the American Board of Radiology (Therapeutic), Dr. Stelzer also is a member of the American Radium Society, the American Society for Therapeutic Radiology and Oncology, and the North American Society for Neuro-Oncology.

For more information about Celilo Radiation Oncology please call (541) 296-7204.