Radiation therapy for prostate cancer

How radiation therapy is given

Also known as radiotherapy, radiation therapy uses a controlled dose of radiation to kill or damage cancer cells so they cannot grow, multiply or spread.

Radiation therapy may be used:

• for localised or locally advanced prostate cancer – it has similar rates of success to surgery in controlling prostate cancer that has spread to the lymph nodes
• if you are not well enough for surgery or are older
• after a radical prostatectomy for locally advanced disease, if there are signs of cancer left behind or the cancer has returned where the prostate used to be
• for prostate cancer that has spread to other parts of the body
• for intermediate and high-risk prostate cancer, it is often combined with androgen deprivation therapy (ADT).

There are 2 main ways of delivering radiation therapy: from outside the body (external beam radiation therapy) or from inside the body (brachytherapy). You may have one of these types of radiation therapy, or you may have a combination of both.

External beam radiation therapy (EBRT)

In EBRT, a machine precisely directs radiation beams to the prostate. Each treatment session takes about 15 minutes. You will lie on the treatment table under the radiation machine. The machine doesn’t touch you but may rotate around you. You can’t see or feel the radiation.

There are different types of EBRT. Your radiation oncologist will talk to you about the most suitable type for your situation. Usually, EBRT for prostate cancer is given Monday to Friday for 4–9 weeks. Some newer forms of EBRT are given in 5–7 treatments over 2 weeks.

EBRT does not make you radioactive and there is no danger to people near you. Most people feel well enough to work and do their normal activities, though fatigue may increase as your treatment continues.

Reducing the risk of bowel side effects

Radiation therapy can cause bowel changes.

To move the bowel away from the prostate and help prevent side effects, the radiation oncologist may suggest a spacer. Before treatment begins, a temporary gel or balloon is injected between the prostate and bowel. This is done by a urologist as a day procedure under a light anaesthetic. The cost of a spacer is not subsidised by Medicare. Ask your doctors what you will have to pay and the benefits for your situation.

The radiation therapist may advise you to drink fluids before each treatment session so you have a full bladder. This will expand your bladder and push the bowel higher up into the abdomen, away from the radiation.

The radiation team may also advise you to go to the toilet to empty your bowels before each treatment. This can help to ensure the prostate is in the same position every time.

Internal radiation therapy (brachytherapy)

Brachytherapy is a type of targeted internal radiation therapy where the radiation source is placed inside the body near the prostate. Giving doses of radiation directly into the prostate can lower the amount of unwanted radiation going into areas such as the rectum and bladder.

There are 2 different types of brachytherapy: permanent and temporary. If you already have significant urinary symptoms or a large prostate, brachytherapy may not be suitable.

How brachytherapy is done

Permanent brachytherapy (seeds)

• Also called low-dose-rate (LDR) brachytherapy.
• Most suitable for people with few urinary symptoms, and small cancers with a low PSA level (less than 10) and a low to intermediate Gleason score or Grade Group.
• Multiple radioactive metal “seeds”, each about the size of a grain of rice, are put into the prostate under a general anaesthetic.
• The radiation oncologist uses needles to insert the seeds through the skin between the scrotum and anus (perineum). Ultrasound is used to guide the seeds into place.
• The procedure takes 1–2 hours and you can usually go home the same or next day.
• The seeds slowly release radiation into the area of the prostate to kill cancer cells.
• There are safety issues for patients and others.
• The seeds lose their radioactivity after about a year. They are not removed from the prostate.

Temporary brachytherapy

• Also called high-dose-rate (HDR) brachytherapy.
• May be offered to people with a higher PSA level and a higher Gleason score or Grade Group. It is often given with a short course of EBRT.
• The radiation is delivered through hollow needles that are inserted into the prostate while you are under anaesthetic.
• The needle implants stay in place for several hours or, in some cases, overnight. You usually will have 1–3 brachytherapy treatments during this time.
• For each treatment, radioactive wires will be inserted into the needles to deliver a high dose of radiation to the prostate in a few minutes.
• The needle implants are taken out after the final radiation dose is delivered. You will have no radiation left in your body.
• There are no safety issues.
• In some cases, the implant procedure is repeated 1–2 weeks later.

Safety precautions after brachytherapy

If you have permanent brachytherapy your body may give off some radiation for a period of time. The levels will gradually fall over a number of months. This radiation only travels a short distance, which means there is little radiation outside your body.

You will still need to take care spending time in close contact with pregnant women and young children for a few weeks or months after the seeds are inserted. Your treatment team will explain the precautions to you. You should use a condom during sex (intercourse and oral) for this precaution time in case a seed comes out (this is rare).

If you have temporary brachytherapy, you will not be radioactive once the wires are removed after treatment, and there is no risk to other people and no special precautions are needed during sex.

Side effects of radiation therapy

The side effects you experience will vary depending on the type and dose of radiation, and the areas treated. You may experience some of the following side effects. Most side effects are temporary and tend to improve gradually in the weeks after treatment ends, though some may continue for longer. Some side effects may not show up until many months or years after treatment. These are known as late effects. Talk to your doctor or treatment team about ways to manage any side effects you have.

Short-term side effects

Fatigue – The effects of radiation on your body may mean you become tired during treatment. Fatigue may build up during treatment and usually improves 1–2 months after treatment ends, but occasionally can last up to 3 months.

Urinary problems – Radiation therapy can irritate the lining of the bladder and the urethra. This is known as radiation cystitis. You may pass urine more often or with more urgency, have a burning feeling when urinating or a slower flow of urine. If you had urinary issues before treatment, you may be more likely to have issues with urine flow. If you see blood in the urine, tell your doctor as this may need treatment. If you are unable to empty your bladder (urinate) right after brachytherapy, you may need a catheter for a few days or weeks.

Bowel changes – Radiation therapy can irritate the lining of the bowel and rectum. You may have smaller and more frequent bowel movements, need to go to the toilet quickly, or feel that you can’t completely empty the bowel. Less commonly, there may be some blood in the faeces (poo or stools). If this happens, let your doctor know as there are treatments that can stop the bleeding.

Ejaculation changes – You may notice that you feel the sensation of orgasm but ejaculate less or no semen after radiation therapy. This is known as dry orgasm, which may be a short-term or permanent side effect. In some rare cases, you may experience pain when ejaculating. The pain usually eases over a few months.

Long-term or late effects

Infertility – Radiation therapy to the prostate usually causes infertility. If you might want to have children, speak to your doctor before treatment about sperm banking or other options.

Urinary problems – Bladder changes, such as frequent or painful urination, can appear months or years after treatment. After brachytherapy, scarring can develop around the urethra, which can block the flow of urine. This can usually be repaired. It is important to let your doctor know if you have any problems with urinating or notice any bleeding.

Bowel changes – Bowel changes, such as diarrhoea, wind or constipation, can appear months or years after treatment. Bleeding from the rectum can also occur. In rare cases, there may be loss of bowel control (faecal incontinence) or blockage of the bowel. It is important to let your doctor know about any bleeding, or if you have pain in the abdomen and difficulty opening your bowels.

Erection problems – Radiation may damage the nerves and blood vessels that control erections. This can make it difficult to get and keep an erection, especially if you have had problems before treatment. Having ADT can also cause problems with erections. Erection problems may take time to appear and can be ongoing or permanent.