Prostate Radiotherapy

Prostate Radiotherapy Preparation

Before you can have your radiotherapy you need to have a CT Planning Scan. At this appointment we will get you in the position you will be in each day for your radiotherapy treatment. You will need to follow some instructions to prepare your bladder and bowel for the CT scan; you will need to follow these instructions for every radiotherapy treatment too. This is because the prostate gland sits very close to the bladder, rectum and small bowel as a result the position of your prostate can vary depending on the contents and size of your rectum and bladder.

If the contents of the bladder and rectum vary between your CT scan and your daily treatment, it could mean the prostate is in a different position to the one we have planned for.

We need you to have:

  • A full bladder
  • An empty rectum

Which helps us to:

  • Increase the accuracy of your treatment
  • Reduce the risk of short and long term side effects


Prior to your CT scan, and radiotherapy treatment, you need to ensure that you are WELL HYDRATED, which means drinking lots of fluid.

We recommend that you aim to drink 2-3 litres of water (4-6 pints) throughout the day in the weeks prior to your CT scan and your treatment as well as during your treatment course.

  • Included: Water + diluted squash
  • Not included: Tea + coffee, fizzy drinks, fruit juices and alcoholic drinks

If you drink a lot of caffeine then you should cut down on this or replace with a decaffeinated alternative.


In order to reduce the size of your rectum and reduce gas it is important to:

  • Reduce the fibre in your diet (do not cut out fibre altogether as this can make you constipated)
  • Reduce the foods and drinks that make you gassy. Eg. Fizzy drinks, beans and pulses, spicy foods, green leafy vegetables such as broccoli and sprouts.

These changes should be carried out 3 days prior to your CT planning scan and the beginning of your treatment, as well as throughout the entirety of your treatment. Approximately a week before your CT scan you will receive a phone call from one of the pre-treatment team. During the phone call we will go through a short questionnaire to determine your current drinking and eating regimes as well as discuss what changes you need to make and when. It is important you are able to hold 500ml of water in your bladder for 30-40 mins. If you have a problem with this please let a member of the team know.

We know it can be difficult to discuss these topics but please be open and honest with us.


At your CT planning scan and each day prior to your treatment you will have to complete bladder and bowel preparation. You will need to use a micro-enema to empty your rectum and drink 500ml of water after emptying your bladder. The details and timings of this preparation will be explained to you when you come for your CT planning scan appointment.


Each day before delivering your radiotherapy treatment we will do an assessment scan to assess your bowels and bladder. If we encounter any issues with bladder filling or the size of your rectum following the initial scan we may need to get you off the treatment bed and begin the bladder and bowel protocol again. This is why we encourage you to be well hydrated and avoid gas forming foods prior to and throughout treatment. When we are satisfied with your positioning we will deliver your treatment.


You will be guided through the timings of your preparation for you CT planning scan and your first radiotherapy treatment but for all subsequent treatments you will not be prompted. If you are unsure about any part of the preparation please speak to one of the team as soon as you can because if the preparation is not followed correctly this can lead to delays in your treatment.


Please note that we will be asking you to remove your shoes and trousers for your CT planning scan and for each of your radiotherapy appointments so please wear clothing and shoes that can be quickly and easily taken on and off. For example, slip on shoes and elasticated waist trousers.

Side Effects

Acute side effects that you may experience whilst having prostate radiotherapy:

  • Urinary side effects – frequency, urgency, nocturia (increased frequency of urination at night)
  • Bowel side effects – loose bowels, diarrhoea, passing wind
  • Fatigue


You will have reviews with your Consultant throughout the course of your treatment. This is to assess how you are managing treatment and discuss any side effects that you may be experiencing.

If you experience any side effects speak to a member of the treatment team. We can then carry out a review and offer advice/ treatment on how best to manage side effects. We are here to guide and support you through your treatment.


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