Both external beam radiotherapy (EBRT) and brachytherapy can cause urinary problems, including:

bladder irritation (radiation cystitis)
needing to urinate more often (urinary frequency)
a sudden urge to urinate (urinary urgency), and you may sometimes leak before you get to the toilet (urge incontinence)
difficulty urinating (urine retention).
Some men may leak urine after radiotherapy, but this is less common. It is more likely if you’ve previously had an operation called a transurethral resection of the prostate (TURP) for an enlarged prostate.

Radiation cystitis
Radiotherapy can irritate the lining of the bladder and the urethra – this is called radiation cystitis. Symptoms include:

needing to urinate more often, including at night
a burning feeling when you urinate
difficulty urinating
blood in the urine.
Symptoms can start within a few days of your first treatment. They usually begin to improve when your treatment ends. But some men get symptoms for several months. And some don’t get symptoms until months or even years after their final treatment.

Symptoms such as blood in the urine can be worrying, but this is quite a common symptom of radiation cystitis.

If you get symptoms of radiation cystitis, tell your doctor or nurse. They can check whether your symptoms are caused by your treatment or an infection.

What can help with radiation cystitis?
There are treatments that can help with radiation cystitis, as well as things you can do yourself.

Lifestyle changes
Drink plenty of fluids (1.5-2 litres, or 3-4 pints a day), but try to avoid fizzy drinks, drinks containing caffeine – such as tea, coffee and cola – and alcohol, as these can irritate the bladder.

Although the evidence for this isn’t very strong, some men find that drinking cranberry juice helps. But you should avoid cranberry juice if you’re taking warfarin to thin your blood.

Bladder wash
If your symptoms are severe, your doctor may suggest a treatment called a bladder wash, such as Cystistat®. This is a liquid medicine that coats and protects the lining of the bladder, making it less irritated. A small tube (catheter) is passed up your penis and fills your bladder with the liquid medicine. You then go to the toilet to empty your bladder.

Urinary frequency and urgency
Some men find they need to urinate more often after having radiotherapy (frequency), or get a sudden urge that’s hard to ignore (urgency). You may also need to urinate more often at night (nocturia). It usually only lasts for a few months after radiotherapy, but if it happens, it might help to drink less in the two hours before you go to bed, and to avoid drinks that irritate the bladder

A small number of men leak urine before they can reach the toilet (urge incontinence). This happens when the bladder muscles twitch and squeeze (spasm) without you controlling them. This pushes urine out before you’re ready.

What can help with urinary frequency and urgency?
There are treatments that can help with urinary frequency and urgency, as well as things you can do yourself.

Bladder retraining
If you need to urinate more often than usual or sometimes leak before reaching the toilet, you could try a technique called bladder retraining. This can help you control when you urinate, and help you hold on for longer. Speak to your specialist continence nurse or physiotherapist for more information.

Medicines
Drugs called anti-cholinergics can help to reduce frequency, urgency and leaks. If you can’t have anto-cholinergics, you may be offered mirabegron (Betmiga®) tablets.

Percutaneous posterior tibial nerve stimulation (PTNS)
This treatment may help some men to urinate and leak urine less often. A needle is placed under the skin just above your ankle. A low electrical current is passed through the needle to affect the nerves that control urination. This can help stop the bladder from emptying before it’s full.

You’ll normally have PTNS once a week for 12 weeks. Each treatment lasts about half an hour. PTNS has no serious side effects, although the area where the needle enters the skin may feel a little sore afterwards.

Sacral nerve stimulation (SNS)
This is sometimes called Sacral Neuromodulation (SNM). A small wire (called an electrode) is surgically placed against the sacral nerve in your lower back. The other end of the wire is connected to a small box (called a stimulation box). The SNS device makes mild electrical pulses that stimulate the sacral nerve to help you regain control of your bladder.

This treatment may help to reduce how often you urinate and leak urine. It is quite a new treatment and is only offered at some hospitals.

You will need two operations to fit the SNS device. Both are usually done under local anaesthetic or sedation. In your first operation, the electrode will be connected to a temporary stimulator box placed outside the body. This is to see if SNS works for you. You will have this device for two to four weeks. Depending on whether the SNS device worked for you, the second operation will either be to put in a permanent device, or remove the temporary one.

In the second operation, they will reopen the cut made in your lower back to put in a stimulator box about the size of a two-pound coin under the skin. This is connected to the electrode touching the sacral nerve.

Like all treatments there are risks in having a SNS device, such as infection, pain or discomfort where the SNS device has been put in or parts of the device breaking. SNS is not suitable for everyone. Your doctor will talk to you about whether you’re suitable for SNS.

Botulinum toxin (BOTOX®)
Injecting BOTOX® into the wall of the bladder can help stop the bladder squeezing out urine before it’s full. This is quite a new treatment for urinary frequency and urgency and it’s not available in all hospitals.

Difficulty urinating
Some men find it hard to empty their bladder properly after radiotherapy – this is called urine retention. This may be more likely if you have an enlarged prostate. Radiotherapy, particularly brachytherapy, can cause the prostate to swell and block the urethra, leading to urine retention. It can also cause the urethra to become narrow – this is called a stricture.

A small number of men may get urine retention after radical prostatectomy, HIFU and cryotherapy.

Chronic urine retention
This is where you can’t empty your bladder fully, but can still urinate a little. The first signs often include:

leaking urine at night
feeling that your abdomen (stomach area) is swollen
feeling that you’re not emptying your bladder fully
a weak flow when you urinate.
Tell your doctor or nurse if you get any of these symptoms. Chronic urine retention is usually painless, but the pressure of the urine can cause the bladder muscles to slowly stretch and become weaker. This can cause urine to be left behind in the bladder when you urinate. You may be more likely to get urine infections, bladder stones, blood in your urine or kidney problems.

Treatments for chronic urine retention include:

a catheter to drain urine from the bladder
drugs (alpha blockers or 5-alpha-reductase inhibitors)
drugs called 5-alpha-reductase inhibitors, which shrink the prostate
surgery to widen the urethra or the opening of the bladder.
Acute urine retention
This is when you suddenly and painfully can’t urinate – it needs treating straight away. If this happens, call your doctor or nurse, or go to your nearest accident and emergency (A&E) department. They may need to drain your bladder using a catheter.. Make sure they know what prostate cancer treatment you’ve had, especially if you have recently had a radical prostatectomy