Heated chemotherapy for non muscle invasive bladder cancer

For this treatment, you have the chemotherapy drug mitomycin C into your bladder. At the same time, a small microwave probe heats up your bladder wall.

This treatment is also called:

  • hyperthermic mitomycin C
  • intravesical microwave hyperthermia with chemotherapy
  • the Synergo technique

The heat treatment appears to make the cancer cells more sensitive to the chemotherapy. Doctors think this may make the chemotherapy work better and improve the results.

When do you have heated chemotherapy?

You might have this treatment for high risk non muscle invasive bladder cancer if:

  • BCG treatment has not worked
  • you're unable to have BCG treatment

You can have this treatment either before or after surgery (TURBT). You only have it as part of a clinical trial. There is not yet enough evidence for how well it works to make it more widely available.

You have this treatment every week for 4 to 8 weeks. You may have it for a longer period if you have had it after surgery.

Each treatment lasts around 40 to 60 minutes.

What happens

Where you have it

You usually have treatment at the cancer day clinic.

Before you start 

This treatment is part of a clinical trial only. So, you’ll usually meet a research nurse who will explain what will happen during the clinical trial and what to expect.

You need to have blood tests to make sure it’s safe to start treatment. You have these either a few days before or on the day you start treatment. You have blood tests before each round or cycle of treatment.

On the day the nurse will test your urine to check if you have any infection or sign of blood.

Before each treatment, you need to stop drinking fluids for up a certain amount of time before treatment starts. This stops the urine from diluting the drug in your bladder and will help you hold the urine more easily. Your hospital will tell you when to stop drinking

How you have it

On the day you’ll have to undress from the waist down. The doctor will ask you to lay down on your back on the couch.

You have the treatment through a thin tube (catheter). The catheter goes into your bladder through the urethra. The urethra is the tube that carries wee (urine) from the bladder out of the body.

The doctor or nurse puts a local anaesthetic into your bladder to make the procedure more comfortable. They put the catheter into your bladder.  There is a probe at the end of the catheter that uses microwaves to heat up your bladder lining. Your doctor may use an ultrasound to check it’s in the right place before they start treatment.

Your doctor passes chemotherapy into your bladder through the catheter. They continuously pump the chemotherapy so it circulates out of the bladder to cool, and then goes back in again. This prevents it from getting too hot. Your doctor monitors the temperature of the chemotherapy in your bladder.

After the treatment, your doctor or nurse drains the chemotherapy out of your bladder and takes out the catheter.

When you go home

Bladder cancer and its treatment can be difficult to cope with. Tell your doctor or nurse about any problems or side effects that you have. The nurse will give you telephone numbers to call if you have any problems at home.

There may be a small amount of chemotherapy left in your bladder after treatment. So you should:

  • drink lots of fluid (2-3 litres) after this treatment to helps clear your system of chemotherapy
  • be careful when you pass urine so that you don't get it on your skin - men should sit down to pass urine, to reduce the chance of splashing
When using the toilet you must wash your genitals and hands immediately with warm soapy water to prevent the chemotherapy irritating your skin.

Possible side effects

You get fewer side effects having chemotherapy into your bladder than you would having chemotherapy into a vein. This is because the drug tends to stay in your bladder. So very little of it gets into your bloodstream.

Some of the side effects might include:

Irritation of the bladder 

Chemotherapy can irritate your bladder. You may feel as if you have a bad urine infection (cystitis). This can make you:

  • pass urine very often
  • pass urine with urgency
  • feel uncomfortable
  • feel some pain

Blood in your urine

You may have a small amount of bleeding. Contact the hospital immediately if:

  • the bleeding is getting worse
  • there are blood clots in your urine
  • you have severe pain when passing urine
  • you can't pass urine and have severe pain

Skin rash and itching

You may get a rash on your hands or feet for a short time after having this treatment. Some skin rashes may get red, sore and swollen. Some people get severe itching. Contact your doctor if you get any of these symptoms.


Some chemotherapies can increase your risk of getting an infection. You're also at increased risk of infection from having a catheter put in. If you generally feel unwell, severe pain, bad smelling urine or discharge or have a temperature contact your doctor.   

Allergic reaction

There is a risk of having an allergic reaction to the chemotherapy. But this is rare. If it does happen the nurse gives you medicines to control the reaction. Tell the doctor or nurse if you feel unwell at any time.

  • Synergo for non-muscle-invasive bladder cancer
    National institute for Health and Care Excellence (NICE), 2021

  • Intravesical microwave hyperthermia and chemotherapy for non-muscle-invasive bladder cancer
    National institute for Health and Care Excellence (NICE), 2018

  • Intravesical radiofrequency induced hyperthermia enhances mitomycin C accumulation in tumour tissue
    F J P V Valenberg and other
    International Journal of Hyperthermia, 2018. Volume 34, Issue 7, Pages 988 – 993

  • EAU Guidelines on Non-muscle-invasive Bladder Cancer (TaT1 and CIS)
    M Babjuk and others
    European Association of Urology, 2022

  • Guidelines for the Administration of Intravesical Therapies
    British Association of Urological Nurses, 2010

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
02 Nov 2022
Next review due: 
02 Nov 2025

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