What are the possible side effects of prostate radiation therapy?


There are two types of side effects of prostate radiation therapy:

  • early/acute side effects, mainly urinary (difficulty or urgency to urinate), digestive (constipation, diarrhea, rectal pain) or sexual (erectile dysfunction and libido). These side effects can be managed with drugs prescribed by the radiation oncologist;
  • late side effects, mainly urinary (difficulty to urinate, traces of blood in urine), digestive (blood in stool) or sexual (erectile dysfunction). They appear between 3 months and 3 years after the treatment end and are irreversible. These complications are rare, less than 10% of patients will develop them. A specific management is put in place to limit their impact on the patient’s quality of life.

Like for all side effects of radiation therapy, the side effects of prostate radiation therapy can be classified in acute (occurring during and up to 3-6 months after treatment end) and late (more than 6 months after radiation therapy) side effects. It should be noted that their intensity and the risk of occurrence vary greatly among patients. These toxicities may concern the urinary, digestive systems, or the sexual function.

Acute side effects may concern the bladder (increase in the frequency of urination particularly at night, difficulty in urinating, burning urination, or urinary urgency). Digestive toxicities include diarrhea (or sometimes constipation), false feeling to pass stool, and pain in the rectal area. Sexually, erectile dysfunction and loss of libido may occur, especially if hormone therapy is concomitantly prescribed. These acute side effects are very well managed with symptomatic treatments (e.g. anti-diarrhea drugs, drugs to help urinating) that are prescribed, if necessary, by the radiation oncologist.

Late side effects are much less frequent, as less than 10% of patients will develop such complications. At the urinary level, they include difficulty in urinating (drugs to facilitate urination are prescribed), increased frequency of urination, or traces of blood in urine (due to radiation cystitis, which is similar to fibrosis of a part of the bladder). Digestive late toxicities are rare (presence of blood in stool due to radiation proctitis). These symptoms require specialized care because sometimes they can be quite disabling. Some patients experience erectile dysfunction that can be treated by a specialist.