MONDAY, Nov. 6, 2006 (HealthDay News) -- Prostate cancer patients treated with intensity-modulated radiation therapy (IMRT) suffer fewer long-term gastrointestinal side effects than those treated with another form of radiotherapy, new research shows.
Researchers at Fox Chase Cancer Center in Philadelphia analyzed data on 489 men treated with IMRT and 928 men treated with the second type of radiation therapy, called three-dimensional conformal radiation therapy (3D CRT).
The researchers evaluated gastrointestinal side effects such as short-term diarrhea and longer-term bowel dysfunction. They also looked at genitourinary side effects such as urinary frequency, urgency, painful or difficult urination, or symptoms of urinary obstruction.
"There were no differences in the reporting of acute gastrointestinal or genitourinary side effects for the two treatment modalities," study author Dr. Alexander Kirichenko said in a prepared statement.
"However, as the data are beginning to mature, we're seeing more long-term gastrointestinal side effects in the men treated with 3D CRT," Kirichenko added.
The finding is especially interesting because patients treated with IMRT receive higher radiation doses than those exposed to 3D CRT.
However, three years after treatment, gastrointestinal side effects were noted in 10.4 percent of patients treated with 3D CRT and in 6.3 percent of those treated with IMRT.
"Despite the specific findings pertaining to 3D CRT technique and the gastrointestinal side effects, men treated with either [technique] have acceptable rates of side effects at this point in our analysis, particularly when compared to data from surgical outcomes," Kirichenko said.
The findings were expected to be presented Sunday at the annual meeting of the American Society for Therapeutic Radiology and Oncology.
Both IMRT and 3D CRT enable doctors to precisely target cancer with multiple radiation beams, but IMRT allows doctors to control radiation dose intensity with far smaller radiation beams.
The American Academy of Family Physicians outlines prostate cancer treatments.