There appears to be no major differences between the two treatments in the percentage of men still alive 10 years after treatment. Whether there are differences in results after that time is uncertain. Radiation may be especially useful in patients in whom there is a high chance that the tumor has spread through the capsule of the prostate but is still confined to the immediate surrounding tissues. There are side effects associated with radiation therapy. Some degree of discomfort with urination, frequent and urgent urination, or diarrhea is common during radiation therapy.
Side effects are especially likely during the second half of the treatment course.
In most patients, these symptoms usually go away within a few months. Most men treated with radiation therapy for prostate cancer eventually become impotent. As is the case with patients treated by radical prostatectomy, younger and more sexually active men are more likely to remain potent. Hormonal therapy may be useful because prostate cancer cells depend, at least partially, upon male hormones for growth. Testosterone is the most important of these hormones.