UC Davis research finds newer radiation therapy technology improves patients' quality of life
Fewer permanent disabilities and other side effects from treatment reported
Patients with head and neck cancers who have been treated with newer, more sophisticated radiation therapy technology enjoy a better quality of life than those treated with older radiation therapy equipment, a study by UC Davis researchers has found.
The findings, presented today at the Multidisciplinary Head and Neck Cancer Symposium in Phoenix, is the first of its kind to measure long-term quality of life among cancer patients who have undergone radiation therapy for advanced cancers of the throat, tongue, vocal cords, and other structures in the head and neck.
Allen Chen, assistant professor and director of the residency and fellowship training program in the UC Davis Department of Radiation Oncology, reported that the use of intensity-modulated radiation therapy, or IMRT, was associated with fewer long-term side effects, which led to a better quality of life. Standard radiation therapy to the head and neck has been known to affect a patient's ability to produce saliva, taste, and even chew food. These side effects historically have resulted in permanent disabilities.
"With the newer machines using IMRT, physicians are skillfully able to deliver higher doses of radiation to the tumor and lower doses to surrounding normal tissues than ever before," Chen said. "I wanted to see if this theoretical advantage resulted in any tangible improvements in quality of life for patients."
For the study, Chen used the University of Washington Quality of Life instrument, a standardized, previously validated questionnaire that patients complete after radiation therapy. The survey was administered prospectively to 155 patients at UC Davis Cancer Center diagnosed with head and neck cancers, 54 percent of whom were initially treated with IMRT and 46 percent of whom were treated with other radiation therapy technologies. All of the patients receiving IMRT also underwent image-guided radiotherapy (IGRT), which has been available at UC Davis since 2006 and is used to increase accuracy by taking a high-quality scan of the tumor daily.
Chen and his colleagues found that the early gains observed in quality of life became magnified over time for those who received IMRT treatment. For example, one year after treatment, 51 percent of the IMRT patients rated their quality of life as very good or outstanding, compared to 41 percent of non-IMRT patients. But two years after treatment, the percentages changed to 73 percent and 49 percent respectively.
John Torres of Sacramento was diagnosed in early 2010 with a large tumor at the base of his tongue on the right side of his throat. Fearing that surgery might result in the loss of his voice box, Torres opted for IMRT with IGRT and had 33 treatments.
Torres, now 73 and in remission, points out that the treatments were "no walk in the park," but said he is faring much better than he expected. Although his mouth is often dry and he has lost some taste sensation, he is enjoying an active life.
"I golf a couple of time a week," he said. "My wife and I like to socialize. We go out, and we dance. And we are planning to take a cruise through the Panama Canal in next two or three months. Life has gotten back to pretty much exactly what it was."
Chen acknowledged that quality of life is difficult to measure because of its subjective nature. Nonetheless, he said the findings support the more widespread use of IMRT in radiation clinics throughout the country.
"There has been some reluctance to utilize it because it is expensive, resource intensive, and takes on average 10 to 12 hours to prepare a single patient's treatment," he said. "I think this is further evidence that our investment in developing newer technologies is really paying off."
Chen, whose findings will be highlighted at a symposium press briefing on Friday, Jan. 27, received no outside funding for the research. Other investigators who collaborated on the study were Gregory Farwell, Quang Luu, Esther Vazquez, Derick Lau, and James Purdy, all from the UC Davis Cancer Center.