TUESDAY, March 25, 2008 (HealthDay News) -- Magnetic resonance imaging (MRI) can help predict the risk of cancer recurrence in prostate cancer patients who are about to have radiation therapy, a new U.S. study says.
Researchers from the University of California, San Francisco conducted a retrospective review of MRI images taken before 80 prostate cancer patients had external beam radiation therapy. The MRI images were examined for details of tumor characteristics, and these were compared to patient outcomes.
The researchers concluded that the presence and degree of "extracapsular extension" (the spread of cancer beyond the membrane surrounding the prostate gland) that could be seen on the pre-treatment MRI images was an important predictor of post-treatment cancer recurrence and spread.
Patients with extracapsular extension greater than 5millimeters (about the size of a pencil eraser) were more likely to suffer cancer recurrence and spread.
"This the first study to show that MRI detection and measurement of the spread of prostate cancer outside the capsule of the prostate is an important factor in determining outcome for men scheduled to undergo radiation therapy," study co-author Fergus V. Coakley, professor of radiology and urology, and vice chair for clinical services and section chief of abdominal imaging in the department of radiology, said in a prepared statement.
"Patients with substantial extracapsular spread of prostate cancer may wish to discuss options for more aggressive therapy with their treating physicians," Coakley said.
The study was published in the April issue of the journal Radiology.
In 2008, it's estimated that more than 186,320 new cases of prostate cancer (mostly in men over age 65) will be diagnosed in the United States, according to the National Cancer Institute. When prostate cancer is diagnosed and treated early, the five-year survival rate is almost 100 percent. But the survival rate drops significantly once cancer spreads or recurs beyond the prostate.
The American Cancer Society has more about prostate cancer.