Planning external beam radiotherapy

You will need to visit the hospital once or twice so your treatment can be planned. External beam radiotherapy is planned by an oncologist, a doctor who specialises in cancer treatments.

As part of your planning you will have a CT scan, which takes x-rays to build up an image of your body. There may be some preparation you need to do before the scan such as following a special diet and having an enema. This is to make sure the pictures are as clear as possible. The hospital staff will tell you what preparation is needed.

You may need to have tiny tattoos or permanent marks drawn on your skin. The radiographers who give you your treatment will ask your permission to do this. Some men may have small very small gold grains put into their prostate gland. These act as markers for the radiographers as the position of your prostate varies slightly from day-to-day.

These procedures all help to make sure the radiographers can position you accurately for your treatment. The treatment isn’t painful but you do have to lie still for a few minutes.

External beam radiotherapy

External beam radiotherapy is given in the hospital radiotherapy department. It’s usually given as daily sessions from Monday–Friday, with a rest at the weekend. The course of treatment may last from 4–8 weeks.

Planning external radiotherapy

External beam radiotherapy is planned by an oncologist. Planning is a very important part of radiotherapy and may take one or two visits to hospital. The treatment is carefully planned to make sure it is as effective as possible. 

As part of your planning, you’ll be asked to have a CT scan, which takes x-rays of the area to be treated.

Before your CT scan you may need to follow a special diet. Occasionally, you may be asked to have an enema. This involves having a small amount of liquid passed into your rectum through a thin tube. The liquid will help you to empty your bowel before the CT images are taken. Having an empty bowel gives very clear CT images and this helps your radiographers plan your treatment.

Just before the scan you may also be asked to drink a few glasses of water to fill up your bladder. This will also help to give clear CT images. If you need to follow a special diet, have an enema or drink fluids before your scan, you will be given written information about this.

During your planning tiny tattoos or permanent marks may be drawn on your skin. These show where the radiotherapy is to be given. They help the radiographers position you accurately and set up where the treatment will be given.

The marks are usually permanent. They are the size of pinpoints and will only be done with your permission. Having the tattoos done can cause some discomfort but this won’t last long.

Some men may have very small gold grains put into their prostate gland during an outpatient procedure. The prostate gland moves when you breathe or when your bowel is full. The gold grains act as markers to help your oncologists plan each of your daily treatments accurately. This helps to reduce side effects and damage to organs that are close to the prostate gland.

There are other ways of planning your treatment accurately. Your hospital team can tell you more about the techniques they use.

Radiotherapy can make your skin sore. During your planning appointments you’ll be given advice about how to look after your skin.

Treatment sessions

At the beginning of each session, the radiographer positions you carefully on the couch and makes sure you are comfortable. You will be alone in the room during treatment. But you can talk to the radiographer who is watching from the next room. Radiotherapy is not painful, but you need to lie still for a few minutes while it’s given.

My radiotherapy was a strange experience since in spite of lying on a couch under an impressive whizzing machine behind thick doors, I felt absolutely nothing.


Back to External beam radiotherapy explained

What is external beam radiotherapy?

External beam radiotherapy is the most common type of radiotherapy. A big machine directs external radiotherapy beams at the affected area.