What to expect from radiotherapy for prostate cancer

External radiotherapy uses scans to map the prostate and nearby organs, followed by treatment visits in which you lie still while the machine delivers radiation. Some people receive a shorter course, while others may have a radioactive source placed temporarily inside the prostate. Your specialist chooses the approach according to tumour features, previous treatment and overall health.

During or after treatment, you may notice more frequent or urgent urination, a weaker stream, bowel looseness or rectal irritation. Tiredness and changes in erections can occur. Symptoms often need monitoring rather than treatment interruption, but your team can offer medicines, diet advice or other support.

Follow instructions about bladder filling or bowel preparation before each visit, because a consistent position helps the team target the prostate. Bring an up-to-date medicine list and mention urinary symptoms, anticoagulants and bowel conditions. Drink fluids as advised, use prescribed medicines as directed, and tell the team early if passing urine becomes difficult or bowel symptoms interfere with eating, sleep or work.

Call your treatment team urgently if you cannot pass urine, have heavy rectal bleeding, severe abdominal or pelvic pain, repeated vomiting, fever or rapidly worsening weakness. Seek emergency help for collapse, confusion or breathing difficulty. A small amount of irritation can be expected with some treatments, but a sudden or severe change needs assessment.

Ask whether external treatment or an internal approach is suitable, how bladder and bowel preparation works, and how your existing urinary symptoms affect planning. Ask about sexual-health support, medicines for irritation, activity during treatment and the schedule for PSA tests and follow-up reviews.