Research Activities, February 2014
Intensity-modulated radiotherapy no better than less costly conformal radiotherapy for treating prostate cancer after surgery
Comparative Effectiveness Research
Is intensity-modulated radiotherapy (IMRT) more effective in treating men with prostate cancer following radical prostatectomy than the somewhat older, and less costly treatment of conformal radiotherapy (CRT)? A new study suggests the answer is "no." Prostate cancer is the most common malignancy in American men, with diagnosis of 240,000 new cases and 30,000 deaths from the cancer each year.
Many men who choose to have a radical prostatectomy will require radiation therapy afterwards, either to prevent a recurrence or to treat recurrent cancer. Although IMRT reduces the amount of radiation experienced by organs adjacent to the prostate, such as the bladder and rectum, it requires more complicated treatment planning than conventional CRT, and is reimbursed by Medicare at a higher rate.
A previous study, funded by AHRQ, showed that for patients receiving radiation therapy without prostatectomy, IMRT was associated with lower gastrointestinal morbidity and hip fractures compared to CRT. In the current study, the researchers from the University of North Carolina at Chapel Hill compared outcomes for 457 men who underwent IMRT with those for 557 men who underwent CRT. They found that the proportion of patients who underwent IMRT after prostatectomy increased from zero in 2000 to 82.1 percent by 2009. Despite this dramatic increase in use of the newer form of radiotherapy, none of the rates of long-term morbidity with IMRT differed significantly from those for patients who underwent CRT. This included the rates of gastrointestinal morbidity, urinary incontinence, other urinary morbidity, or erectile dysfunction. Furthermore, the two types of radiotherapy did not differ significantly in the likelihood of subsequent treatment for recurrent prostate cancer.
The findings were based on data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)–Medicare-linked database of patients who received radiation therapy between 2002 and 2007. The study was funded by AHRQ (Contract No. 290-2005-0040I).
More details are in "Comparative effectiveness of intensity-modulated radiotherapy and conventional conformal radiotherapy in the treatment of prostate cancer after radical prostatectomy," by Gregg H. Goldin, M.D., Nathan C. Sheets, M.D., Anne-Marie Meyer, Ph.D., and others in the June 24, 2013, JAMA Internal Medicine 173(12), pp. 1136-1143.