A trial looking for the best way to make sure your bladder is the same size during each radiotherapy treatment for prostate cancer

If you have prostate cancer that has not spread beyond your prostate, you will usually have radiotherapy to treat it. The prostate is a small gland about the size of a walnut. It surrounds the first part of the tube that carries urine from the bladder to the penis (the urethra).

Because it is so close to the bladder, the prostate’s position can vary from day to day, depending on how much urine is in your bladder. But it is important that your prostate is in the same position for each radiotherapy treatment you have. Having the same amount of fluid in your bladder for each treatment will help this.

Before you have treatment your radiographer may ask you to fill your bladder by drinking some water. Researchers in this trial are comparing a new set of instructions with those staff already use. They want to see if the new guidelines can better help the bladder to be the same size before each treatment.

Sometimes, men have bladder irritation caused by prostate radiotherapy. The amount of urine in the bladder may be linked to this side effect. So researchers will also collect urine samples to see if there are any features (biomarkers) in the urine that could be used to predict who may have this side effect. The main aims of this trial are to

• See if a new set of fluid guidelines helps to make the bladder the same size before each radiotherapy session
• Assess side effects of men having radiotherapy, and see if biomarkers in the urine could help with this