Intensity-Modulated Radiation Therapy optimal for localized prostate cancer
|April 17, 2012|
A treatment for localized prostate cancer known as Intensity-Modulated Radiation Therapy (IMRT) does a better job at reducing certain side effects and preventing cancer recurrence than conventional conformal radiation therapy (CRT), according to a study published in the April 18 issue of the Journal of the American Medical Association (JAMA).The study, titled “Comparative Effectiveness of Management Options for Localized Prostate Cancer” and funded by the Agency for Healthcare Research and Quality, also showed IMRT to be as effective as proton therapy, a newer technique that has grown in popularity in recent years.
In 2012, approximately 241,740 American men will be diagnosed with prostate cancer.
Paul Godley, MD, PhD, director of the Ethnicity, Culture and Health Outcomes (ECHO) program and adjunct professor of epidemiology at UNC Gillings School of Global Public Health, led the study with senior author Ronald Chen, MD, MPH, assistant professor of radiation oncology and a research fellow at the Sheps Center for Health Services Research at UNC-Chapel Hill.
In addition to Godley, other authors with public health school affiliations are health policy and management assistant professor William Carpenter, PhD; biostatistics student and UNC Lineberger Comprehensive Cancer Center research associate YunKyung Chang, PhD; health policy and management associate professor Bryce Reeve, PhD; and epidemiology professor Til Stürmer, MD, PhD.
“In the past 10 years, IMRT has largely replaced conventional CRT as the main radiation technique for prostate cancer, without much data to support it,” Chen said. “This study validated our change in practice, showing that IMRT better controls prostate cancer and results in fewer side effects,” Chen said.
The study shows that, when compared to CRT, IMRT was associated with fewer diagnoses of gastrointestinal (GI) symptoms such as rectal bleeding or diarrhea, fewer hip fractures and less additional cancer therapy, but more difficulty with sexual function. Proton therapy also was associated with more GI problems than IMRT.
The UNC team used Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data from 2000-2009 for approximately 13,000 patients with non-metastatic prostate cancer. SEER is composed of 16 population-based cancer registries, representing approximately 26 percent of the U.S. population.
“This type of research is critical, comparing one type of treatment with alternatives so that patients and their providers can arrive at the best decisions for each individual,” said Tim Carey, MD, director of the Sheps Center for Health Services Research and adjunct professor of epidemiology at the public health school.
CRT, IMRT and proton therapy represent three types of radiation, each attempting to treat a tumor while minimizing radiation to surrounding organs. Proton therapy use in prostate cancer is controversial because of its high cost and unproven benefit compared to other standard forms of radiation such as IMRT.
Other UNC authors are Greg Golden, MD; Jordan Holmes; Anne-Marie Meyer, PhD; Nathan Sheets, MD; and Yang Wu, PhD.
Chen and many of the authors are members of the UNC Lineberger Comprehensive Cancer Center.
Additional funding and support for this research was provided by UNC Lineberger Comprehensive Cancer Center’s Integrated Cancer Information and Surveillance System (ICISS) and the state of North Carolina’s University Cancer Research Fund.