External beam radiotherapy

On this page we talk about how external beam radiotherapy can be used to try to get rid of localised prostate cancer (cancer that hasn’t spread outside the prostate) or locally advanced prostate cancer (cancer that has spread to the area just outside the prostate).

Radiotherapy can also be given to some men whose cancer has spread to other parts of the body (advanced prostate cancer). It may be used to help control the cancer or, more commonly, to relieve symptoms.

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Watch Ally's story below for one man's experience of external beam radiotherapy. 

How does radiotherapy work?

Radiotherapy aims to destroy prostate cancer cells without causing too much damage to healthy cells. External beam radiotherapy uses high-energy X-ray beams targeted at the prostate from outside the body. These X-ray beams damage the cancer cells and stop them from growing and spreading to other parts of the body (advanced prostate cancer). Radiotherapy permanently damages and kills the cancer cells, but healthy cells can repair themselves and recover more easily.

Radiotherapy treats the whole prostate. It is also sometimes used to treat your seminal vesicles − these are two glands that sit behind your prostate and bladder that produce some of the fluid in semen. Radiotherapy aims to treat all the cancer cells, including any that have spread to the area just outside the prostate. The treatment itself is painless but it can cause side effects that may cause you problems.

You may have radiotherapy to a wider area, including the nearby lymph nodes and bones, if there is a risk that the cancer has spread there. Lymph nodes are part of your immune system and are found throughout your body. The lymph nodes in your pelvic area are a common place for prostate cancer to spread to. But if you do have radiotherapy to a larger area, you will be more likely to get side effects.

Who can have radiotherapy

External beam radiotherapy can be suitable for you if:

• your cancer hasn’t spread outside the prostate (localised prostate cancer)
• your cancer hasn't spread to the area just outside the prostate (locally advanced prostate cancer)
• your cancer has come back after treatment that aimed to cure it (recurrent prostate cancer).

If your prostate cancer is localised or locally advanced, or if you have recurrent prostate cancer, radiotherapy will aim to get rid of the cancer completely.

If you have some types of inflammatory bowel disease (IBD), external beam radiotherapy may not be suitable for you as it could make your bowel problems worse. Talk to your doctor or nurse to discuss if radiotherapy is suitable for you.

Radiotherapy for localised and locally advanced prostate cancer

If you’re having radiotherapy for localised or locally advanced prostate cancer you might also have hormone therapy for six months before, during or after treatment. Hormone therapy can shrink the prostate and the cancer inside it, and make the treatment more effective. Your doctor will let you know if you need hormone therapy and for how long you should have it. If there is a risk of the cancer spreading outside your prostate, you may continue to have hormone therapy for up to three years after radiotherapy. Read more about hormone therapy.

If there’s a risk that your cancer could spread outside the prostate, you might also be offered another type of radiotherapy called brachytherapy alongside your external beam radiotherapy. But this isn’t very common. Brachytherapy gives a high dose of radiation directly into your prostate through the perineum, which is the area between your testicles and back passage. Brachytherapy can be given either before or after treatment with external beam radiotherapy.

Having both types of radiotherapy together means you will have external beam radiotherapy to the prostate and the area just outside it, as well as an extra dose of radiotherapy to the prostate itself. This can help make treatment more effective, but might also mean you’re more likely to get side effects. Find out more about permanent seed brachytherapy and high dose-rate brachytherapy.

Adjuvant radiotherapy

Some men may also be offered radiotherapy to the prostate bed (the area where your prostate used to be) very soon after having surgery to remove prostate (radical prostatectomy). This usually happens if there’s a chance that their cancer may come back or wasn’t completely removed during the operation. This is called adjuvant radiotherapy. It is generally given within the first few months of surgery, but your doctor may suggest waiting until any urinary problems have improved. 

Salvage radiotherapy

Salvage radiotherapy may be offered to men who’ve had surgery (radical prostatectomy). It may be an option if the level of PSA (prostate specific antigen) in your blood doesn’t drop below 0.1 ng/ml in the first four to eight weeks after your surgery, and continues to rise above 0.2 ng/ml. You might also have salvage radiotherapy if your cancer comes back after high-intensity focused ultrasound (HIFU) or cryotherapy. Find out more on treating cancer that has come back.

Other treatment options

Other treatment options for men with localised and locally advanced prostate cancer include:

• active surveillance
• watchful waiting
• surgery to remove the prostate (radical prostatectomy)
• brachytherapy (either permanent seed or high dose-rate)
• hormone therapy
• docetaxel chemotherapy
• high-intensity focused ultrasound (HIFU) or cryotherapy, but these are less common and only available as part of a clinical trial.

Radiotherapy after other treatments for prostate cancer

Radiotherapy can be an option if your cancer has come back after surgery (called salvage or second-line radiotherapy). It may also be possible after HIFU or cryotherapy. Read about treatment options if your cancer comes back.

If you have advanced prostate cancer

If your cancer has spread to other parts of the body (advanced or metastatic prostate cancer), external beam radiotherapy won’t be able to cure your cancer. But you may be offered radiotherapy to areas where the cancer has spread, to help with symptoms such as bone pain. And new research has found that giving radiotherapy to the prostate itself can help some men who’ve just been diagnosed with advanced prostate cancer to live longer. Read more about radiotherapy for advanced prostate cancer.

What types of radiotherapy are there?

There are different types of external beam radiotherapy used to treat prostate cancer. Ask your doctor, nurse or therapeutic radiographer which type of radiotherapy you are being offered, and for how long.

Intensity-modulated radiotherapy (IMRT)

This is the most common type of external beam radiotherapy in the UK. A computer uses the scans from your radiotherapy planning session to map the location of your prostate and the organs near it to work out the precise radiation dose and create a plan for your radiotherapy treatment.

The radiotherapy machine (called a linear accelerator or Linac) gives out beams of radiation that match the shape of the area to be treated as closely as possible. This helps to avoid damaging the healthy tissue around it, reducing the risk of side effects. It also allows the treatment area to get the right doses of radiotherapy to get rid of the cancer. Most radiotherapy centres use a type of IMRT technique called VMAT (Volumetric Arc Therapy). It is also sometimes called RapidArc.

Stereotactic radiotherapy

Stereotactic radiotherapy, also known as stereotactic ablative radiotherapy (SABR), is another type of external beam radiotherapy that is offered in some hospitals. SABR gives a much higher dose of radiation to the treatment area at each treatment session compared to IMRT, but a lower dose overall. You will have fewer treatment sessions with this technique. It is a very precise treatment that can be delivered on a standard Linac machine.

Stereotactic radiotherapy can also be delivered on different machines. Cyberknife® is a specially designed Linac machine that delivers SABR. Your therapeutic radiographer can tell you which machine they will use for your treatment. SABR is newer than other types of radiotherapy, so we don’t yet know how well it works compared to other treatments for prostate cancer. Speak to your doctor, nurse, or therapeutic radiographer for more information.

Proton beam therapy

You might have heard of a type of radiotherapy called proton beam therapy. This uses beams of tiny particles called protons to target and kill cancer cells. It’s mainly used to treat children and adults with very rare types of cancer. Proton beam therapy isn’t used to treat prostate cancer in the UK. This is because standard radiotherapy works just as well as, or better than proton beam therapy for prostate cancer.

What are the advantages and disadvantages of external beam radiotherapy?

What may be important for one person might not be so important for someone else. If you’re offered external beam radiotherapy, speak to your doctor, nurse or therapeutic radiographer before deciding whether to have it. They can tell you about any other treatment options and help you decide if radiotherapy is right for you.

Advantages of external beam radiotherapy 

• If your cancer is localised or locally advanced, radiotherapy will aim to get rid of the cancer completely.
• Many men can carry on with many of their normal activities while having treatment, including going to work and driving.
• Radiotherapy can be an option even if you’re not fit or well enough for surgery.
• Radiotherapy is painless (but you might find the treatment position slightly uncomfortable).
• The treatment itself only lasts around 10 minutes, including the time it takes to get you into position. But you’ll probably need to be at the hospital for up to couple of hours each day to prepare for your treatment. You don’t need to stay in hospital overnight.

Disadvantages of external beam radiotherapy

• You will need to go to a specialist hospital for treatment five days a week for a few weeks. This might be difficult if you have to travel far.
• Your bladder may need to be full, and your bowel may need to be empty during each treatment session. You may be given medicine to help empty your bowel each day and it could take a while to work. Some men may find this process difficult and inconvenient.
• Radiotherapy can cause side effects such as bowel, urinary and erection problems, as well as tiredness and fatigue. But there are usually treatments and ways to help manage these.
• There is a small increase in the risk of getting other cancers after radiotherapy. It is not very common.
• It may be some time before you know whether the treatment has worked.
• If you have radiotherapy as your first treatment and your cancer comes back or spreads, it might not be possible to have surgery afterwards. This is because the radiotherapy may have damaged the prostate and surrounding tissues, making it harder to remove the prostate and increasing the risk of side effects.

What does external beam radiotherapy involve?

You will have your treatment at a hospital radiotherapy department. Before you start your treatment, you’ll see a health professional who specialises in treating cancer with radiotherapy. These can include a specialist doctor known as a clinical oncologist, or a consultant therapeutic radiographer who has had additional training and specialises in prostate radiotherapy. You may also see the cancer nurse at the hospital. They’ll talk to you about your treatment options, including side effects, and ask for your consent for your radiotherapy treatment.

Before your radiotherapy treatment

Prostate radiotherapy preparation

You will need to prepare your bladder and bowel before the radiotherapy CT planning scan and before every radiotherapy treatment. The therapeutic radiographers get you to do this preparation because the prostate sits very close to your bladder, rectum and bowel. So the position of your prostate can change depending on the size of your bladder and rectum. If the size of the bladder and rectum change between your CT scan and your treatment sessions, it could mean the prostate is in a different position. This may affect the accuracy of the treatment and increase your risk of getting side effects.

Your therapeutic radiographer may ask you to have a comfortably full bladder and empty rectum so that the radiotherapy is aimed at your prostate, and that the surrounding areas get as little radiation as possible.

Before you have your CT scan and radiotherapy treatment, you will need to be well hydrated. You should drink about two litres (about four pints) of fluid throughout the day, a few days before your planning CT scan and throughout your treatment. This could be water or diluted squash. Limit fruit juice, fizzy drinks or drinks that contain alcohol or caffeine (like tea or coffee), as these can give you wind or irritate the bladder and make you urinate (pee) more often.

Some foods can make your rectum bigger or fill it up with gas. There are changes you can make to your diet to stop this.

• Reduce the fibre in your diet − but make sure you don’t cut it completely as it can make you constipated.
• Cut down food and drink that make you gassy. These include fizzy drinks, beans and pulses, spicy foods, and green leafy vegetables such as broccoli, cabbage and sprouts.

Every radiotherapy department does things slightly differently so use this as a general guide. Your therapeutic radiographer will go through the preparation with you before you have your CT planning scan, and your first radiotherapy treatment. If the preparation isn’t done properly, it can cause delays in your treatment. Speak to the radiotherapy team if you are unsure about any part of the preparation.

Radiotherapy planning session

You’ll have a CT scan two or three weeks before you start your treatment. Before you have your scan, the therapeutic radiographers will ask you to complete the radiotherapy preparation (see above). Some hospitals will give you a micro-enema, which is a laxative that helps to empty your rectum. You may be asked to empty your bladder before your scan and then drink some water. You will then wait between 30 and 45 minutes for your bladder to fill up. Your radiotherapy team will explain this to you at your appointment.

You'll be taken into the CT scanner and lie down on the scanner couch. You may also have an injection of contrast dye if you need treatment to your lymph nodes. The radiographer then takes a scan that shows the cancer and area around it. This scan is used to plan your treatment, so you won’t be given any results from the scan.

After the scan, your therapeutic radiographer will make three very small permanent marks (tattoos) on your skin. These will help to get you into the same position for each treatment session. It will feel like a pin prick, and the tattoos will be the size of a freckle.

 At some radiotherapy departments, you may have three or four gold seeds (fiducial markers) put inside your prostate. These are about the size of a grain of rice. An ultrasound probe is put into your back passage (rectum) to see your prostate. Hollow needles are then put into your prostate through your perineum (the area of skin between your testicles and back passage), and the seeds are passed through to your prostate. The seeds show up on X-ray images and help the therapeutic radiographer see the exact position of the prostate each day.

Some men find having scans and treatments stressful. If you are anxious about these, speak to your doctor or therapeutic radiographer. They will take the time to go through ways that will help you cope. They may be able to help by playing relaxing music in the room or talk to you during your scan or treatment to keep you distracted. Or you may be able to have medication to help you relax.

It might also help to wear clothing and shoes that are easy to take off and put on, such as slip-on shoes and trousers with an elastic waist, as you will have to do this for your CT planning scan and treatment sessions.

During your radiotherapy treatment

You will usually have one treatment (known as a session or fraction) at the hospital five days a week, with a rest over the weekend. You can go home after each treatment.

If you have localised prostate cancer, the course of radiotherapy usually involves 20 treatment sessions over four weeks. You might hear this called hypo-fractionated radiotherapy.

At some hospitals, you’ll have 37 sessions over seven or eight weeks instead. If you have 37 sessions, you’ll receive a slightly larger overall dose of radiotherapy – but the dose you receive at each session will be lower than if you have 20 sessions.

Studies have shown that having fewer treatment sessions over four weeks works just as well for men with localised prostate cancer as having more sessions over a longer time. The risk of side effects is also similar, and men usually find a shorter course of radiotherapy more convenient, as it involves fewer hospital visits.

If you have SABR, you will have as few as five sessions spread over one or two weeks.

You will have to follow the preparation before each treatment session. Your therapeutic radiographer will explain the treatment process and your radiotherapy preparation instructions. Once you are ready, your therapeutic radiographer will help you get into the exact same position as you were in at your planning scan. They’ll also use the permanent marks made on your body during the CT scan. This will help to make sure that the radiotherapy treatment targets the same area each time. You’ll have to keep very still while they get you in position. The therapeutic radiographers will then leave the room to give you the treatment. They can see you all the time and can come into the room if you need them.

The therapeutic radiographers will take a scan or X-rays to make sure the whole treatment area is covered, and that the radiotherapy targets the same area as in your planning scan. The treatment then starts, and the machine may move around your body. It doesn’t touch you and you won’t feel or see anything. The machine may make a buzzing sound as it works. You’ll need to keep very still, but the treatment only takes around 10 minutes, including the time it takes to get you into position.

You may also hear about image-guided radiotherapy (IGRT). This is used as part of all radiotherapy treatments. Taking images of the treatment area before each treatment allows your therapeutic radiographer to make small changes to the area that is treated, in case the prostate has moved slightly since your last treatment session. This makes sure the surrounding healthy tissue gets as little radiation as possible. IGRT also makes sure the whole treatment area is treated.

It’s safe for you to be around other people, including children and pregnant women, during your course of radiotherapy. The radiation doesn’t stay in your body, so you won’t give off any radiation.

Radiotherapy affects each person differently, but most people are able to carry on with their normal day-to-day activities. You may be fine to continue to work while having radiotherapy, or you may find it tiring and need time off work.

What happens after radiotherapy?

After you’ve finished your radiotherapy, you will have regular check-ups to monitor your progress. This is often called a follow-up appointment. The aim is to:

• check how your cancer has responded to treatment
• help you deal with any side effects of treatment
• give you a chance to raise any concerns or ask any questions.

Your follow-up appointments will usually start two or three months after treatment. Before your follow-up appointment you will usually need a PSA blood test. You will then have PSA tests at least every six months in the first two years. After two years, you may have follow-up appointments less often.

Each hospital will do things slightly differently, so ask your doctor or nurse for more details about how often you will have follow-up appointments.

PSA test

The PSA test is a blood test that measures the amount of a protein called prostate specific antigen (PSA) in your blood. You will usually have a PSA test a week or two before each follow-up appointment, so the results are available at your check-up. This can often be done at your GP surgery. PSA tests are a very effective way of checking how well your treatment has worked.

After treatment, your PSA level should start to drop. Your PSA level won’t fall to zero as your healthy prostate cells will continue to produce some PSA. Every man is different, and your medical team will monitor your PSA level closely.

How quickly your PSA level drops, and how low it falls, will depend on whether you had hormone therapy at the same time as radiotherapy. If you had radiotherapy on its own, it may take 18 months to two years for your PSA level to fall to its lowest level (nadir).

Your PSA level may actually rise after your treatment is finished, and then fall again. This is called ‘PSA bounce’. It could happen up to three years after treatment. It is normal, and doesn’t mean your cancer has come back or you need more treatment.

If your PSA level consistently rises, particularly in a short amount of time, this could be a sign that your cancer has come back. If this happens, your doctor will talk to you about further tests and treatment options if you need them.

Treatment options after radiotherapy

If your cancer does come back, there are further treatments available. You may be offered hormone therapy to control your cancer, or you may be offered another treatment that aims to get rid of your cancer.

Treatments that aim to get rid of cancer that has come back are called salvage treatments. After radiotherapy these may include:

• surgery
• brachytherapy (either permanent seed or high-dose rate)
• hormone therapy
• more external beam radiotherapy
•  high-intensity focused ultrasound (HIFU), or cryotherapy, but there are less common and available only as part of a clinical trial. 

There is no standard or best treatment after radiotherapy – your treatment options will depend on you and your cancer. For example, surgery can be difficult after radiotherapy because radiotherapy changes the prostate tissue and makes it harder for a surgeon to remove the prostate.

You may be more likely to get side effects if you have a second treatment. More research is also needed to look at how well treatments after radiotherapy work in the long term. Read more about what happens if your prostate cancer comes back.

What are the side effects of external beam radiotherapy?

Like all treatments for prostate cancer, radiotherapy can cause side effects. These will affect each man differently, and you might not get all the possible side effects. Side effects happen when the healthy tissue near the prostate is damaged by radiotherapy. Most healthy cells recover so side effects may only last a few weeks or months.

Some side effects can start months or years after treatment. These can sometimes become long-term problems. Sometimes long-term or late side effects after radiotherapy treatment are called pelvic radiation disease.

Before you start treatment, talk to your doctor, nurse or therapeutic radiographer about the side effects. Knowing what to expect can help you deal with them.

If you have hormone therapy as well as radiotherapy, you may also get side effects from the hormone therapy. Read more about the side effects of hormone therapy and how you can manage them.

If you’re having radiotherapy as a second treatment, and you still have side effects from your first treatment, then radiotherapy can make those side effects worse or last longer. It may also cause other side effects. The most common side effects of radiotherapy are described here.

Short-term side effects of radiotherapy

Urinary problems

Radiotherapy can irritate the lining of the bladder and the urethra, which is the tube men urinate (pee) and ejaculate through. It can also cause swelling in the prostate. This can cause urinary problems, such as:

• needing to urinate often, including at night
• a sudden urge to empty your bladder
• a reduced flow
• a burning feeling when you urinate
• difficulty urinating (urine retention)
• blood in your urine.

You might also leak urine (urinary incontinence) after radiotherapy, but this is rare. It may be more likely if you’ve previously had an operation called a transurethral resection of the prostate (TURP) for an enlarged prostate.

Urinary problems tend to start midway through your treatment and may begin to improve several weeks after treatment finishes. But this is different for everyone. Some men may continue to have side effects for longer, while others may not get any side effects at all or have side effects that improve more quickly. If you get any urinary problems, tell your doctor, nurse or therapeutic radiographer. There are treatments to manage them, as well as things you can do to help yourself.

Your medical team may suggest pelvic floor muscle exercises that could help with your urinary problems. You can usually do these at home. Have a look at our interactive online guide for tips on managing urinary problems.

Bowel problems

Your bowel and back passage are close to the prostate. Radiotherapy can irritate the lining of the bowel and rectum (called proctitis), which can cause bowel problems. Before you start radiotherapy, tell your doctor if you’ve had any bowel problems in the past as this could mean you’re more likely to get bowel problems again.

Symptoms vary from man to man, and some men only notice a slight change. Common bowel problems can include:

• passing more wind than usual, which may sometimes be wet
• loose or watery bowel movements (diarrhoea)
• needing to empty your bowels more often, or having to rush to the toilet
• leaking a clear, jelly-like mucus from your back passage
• feeling an urge to empty your bowels, but then not being able to
• a feeling that your bowels haven’t emptied properly
• pain in your abdomen (stomach area) or back passage
• bleeding from your back passage – this isn’t usually anything to worry about, but let your doctor, nurse or therapeutic radiographer know if it happens
• leaking from your back passage (faecal incontinence) – this is very rare.

Bowel problems usually start during or shortly after your treatment and usually begin to settle down several weeks after finishing treatment. Again, this is different for everyone.

Some men may find that some of their side effects last longer, while others may not get any side effects at all, or have side effects that improve more quickly.

Tell your doctor, nurse or therapeutic radiographer about any changes in your bowel habits. There are often things you can do to help yourself and simple treatments available.

If you have anal sex, then bowel problems after radiotherapy may affect your sex life. You can continue giving anal sex to your partner. But if you receive anal sex, your doctor, nurse or therapeutic radiographer may suggest you avoid having anal sex while you are having radiotherapy, and for up to two months afterwards. This is to make sure any bowel problems or sensitivity have settled before receiving anal sex and will be different for everyone. Find out more about how side effects of prostate cancer treatment may affect your sex life if you have anal sex or you’re a gay or bisexual man.

Tiredness and fatigue

The effects of radiation on your body can leave you feeling very tired, especially towards the end of your treatment. Fatigue is extreme tiredness that can affect your everyday life. It can affect your energy levels, your motivation and your emotions – which can be hard to cope with.

Read more about ways to manage your fatigue or have a look at our interactive online guide. You can also speak to our Specialist Nurses about your fatigue - they can talk you through ways to better manage your fatigue.

Problems with ejaculation

You may find ejaculation uncomfortable and notice that you produce less semen during and after treatment. You may also have a ‘dry orgasm’, where you feel the sensation of orgasm but don’t ejaculate. This may feel different to the orgasms you’re used to and some men find this difficult to come to terms with.

Skin irritation and hair loss

During treatment, the skin between your legs and near your back passage may become sore or look a bit like sunburn – but this is rare. Your radiographer will talk to you about how to look after your skin during treatment. Radiotherapy might also make some of your pubic hair fall out. But it usually grows back after treatment.

Long-term or late side effects of radiotherapy

Sometimes side effects can develop much later – several months, or even years, after finishing treatment. If this happens, then these side effects can last a long time.

Talk to your doctor or nurse about your own risk of long-term side effects. You might be more likely to get them if:

• you’re older
• you have diabetes
• you’re very overweight
• you’ve had bowel or prostate surgery in the past
• you’ve had bladder, bowel or erection problems in the past.

Researchers have been looking at whether smoking increases the chance of having long-term bowel and urinary problems after radiotherapy for prostate cancer. At the moment only a small number of studies have been done, so we need more research into this.

Urinary problems

If you had urinary problems during treatment, you may be more likely to develop problems later on. These may be similar to the short-term side effects listed above.

Radiotherapy can cause the urethra to become narrow over time – this is called a stricture. This is more likely if you have brachytherapy combined with external beam radiotherapy. If this happens you will find it difficult to urinate. Symptoms can include:

• feeling that your abdomen (stomach area) is swollen
• feeling that you’re not emptying your bladder fully
• a weak flow when you urinate.

Speak to your doctor or nurse if you get any of these symptoms. Find out more about urinary symptoms. There are also lots of tips for managing urinary problems in our interactive online guide.

Bowel problems

Although bowel problems often improve once treatment has finished, some men find that changes to their bowel habits last a lot longer.

Bowel problems can develop months or years after treatment and may be similar to the short-term side effects listed above. If you had bowel problems during treatment, you may be more likely to develop problems later on.

Try not to be embarrassed to tell your hospital doctor or your GP about any bowel problems. There are treatments that can help. Bowel problems can be common in older men, so it’s possible that they’re caused by something other than radiotherapy. Your hospital doctor or your GP can arrange tests to find out what’s causing the problems, or they may refer you to a bowel specialist.

If you have long-term bowel problems, you might be offered a camera test, such as a flexible sigmoidoscopy or a colonoscopy. This is where a narrow tube with a camera on the end is put into your back passage to check for any damage to the bowel.

Erection problems

Radiotherapy can cause problems getting or keeping an erection (erectile dysfunction). Other treatments for prostate cancer such as hormone therapy, other health problems, certain medicines, tiredness and fatigue, and depression or anxiety can all cause erection problems too. And many men with prostate cancer may have had sexual problems before their treatment. 

Erectile dysfunction caused by radiotherapy often takes a while to appear and it can be up to two years before you notice any problems. Erection problems can also get worse over time.

There are some changes you can make to your lifestyle, as well as treatments that may help you manage erection problems or sometimes prevent them. For example, your doctor may prescribe regular medication to help with erectile dysfunction after your radiotherapy. These often work best if you start them soon after radiotherapy. Talk to your doctor, nurse or therapeutic radiographer to find out more.

Find out more about erection problems, including what treatment is available and practical tips to help with your sex life. There are also lots of tips in our interactive online guide.

Having children

Radiotherapy can damage the cells that make semen and cause you to have a dry orgasm (where you don’t ejaculate). You may want to consider storing your sperm before you start radiotherapy, so that you can use it later for fertility treatment – if you want to. Ask your doctor, nurse or therapeutic radiographer about sperm storage.

There is a very small chance that radiotherapy could affect any children you might conceive during treatment. If there is a chance of your partner getting pregnant, you may want to use contraception over the period you are having radiotherapy and for up to a year after. You can also ask your doctor, nurse or therapeutic radiographer for advice. It is safe for you to have sex with your partner – you won’t pass on your cancer or any radiation.

Lymphoedema

If your lymph nodes are treated with radiotherapy, there is a small chance that fluid might build up in your tissues. This is called lymphoedema. It usually affects the legs, but it can affect other areas, including the penis or testicles. It can occur months or even years after treatment. Speak to your doctor or nurse if you start to get any unusual swelling. Read more about treatments that can help manage the symptoms of lymphoedema.

Hip and bone problems

Radiotherapy can damage the bone cells and the blood supply to the bones near the prostate. This can cause pain, and hip and bone problems later in life. Hormone therapy can also weaken your bones, so you might be slightly more likely to have hip and bone problems if you have both hormone therapy and radiotherapy.

Other cancers

Radiotherapy can damage the cells in the tissues surrounding the prostate. There is a very small chance that this could increase your risk of bladder or bowel cancer. It would take at least 5 to 10 years after having radiotherapy treatment for a second cancer to appear.

Questions to ask your doctor, nurse or radiographer

You may find it helpful to keep a note of any questions you have to take to your next appointment.

• What type of radiotherapy will I have?
• How many sessions will I need?
• What other treatment options do I have?
• What are the possible side effects and how long will they last?
• What treatments are available to manage the possible side effects from radiotherapy?
• Will I have hormone therapy and will this carry on after radiotherapy?
• How and when will I know if radiotherapy has worked?
• If the radiotherapy doesn’t work, which other treatments can I have?
• Who should I contact if I have any questions?
• What support is there to help manage long-term side effects?

List of references and reviewers

Updated: August 2022 | Due for Review: August 2025