CT scan

A computerised tomography (CT) scan can show whether the cancer has spread to the lymph nodes near the prostate. You may have this scan if there is a risk of your cancer spreading and you are considering active treatment options such as radiotherapy or radical prostatectomy.

The scanner takes X-rays of your pelvis, which are fed into a computer to create an image of the prostate and the surrounding tissues, including the lymph nodes. The doctor can then look more closely for possible signs that the cancer has spread.

Your hospital will give you information on what will happen at your appointment and may ask you not to eat or drink for a few hours before the scan. When you arrive at the radiology department, you will be given an injection of a dye. This can give you a warm feeling and you may feel that you need to go to the toilet. The dye helps the doctor see the prostate and surrounding organs on the scan. It is not radioactive. You will also be asked to take off any metal jewellery, as this can interfere with the machine.

You should let the X-ray department know well in advance of your scan appointment if:

• you already know you are allergic to the dye
• you have any other allergies
• you are taking the drug metformin for diabetes

The CT scanner is shaped like a large doughnut. You will be asked to lie on a sliding table, which moves through the hole in the middle of the machine. The radiographer will leave the room but you will be able to speak to them through an intercom and they can see you at all times. You will need to keep still and may be asked to hold your breath for short periods of time. The scan itself takes 10-20 minutes and you will be able to go home afterwards. It can take up to two weeks for all of the pictures taken by the scanner to be put together and looked at by the radiologist and your urologist.