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Having radiotherapy

Find out about what happens when you have radiotherapy for advanced bowel cancer.

Radiotherapy uses high energy x-rays to kill cancer cells.

Radiotherapy can shrink the cancer, relieve symptoms, and help you feel more comfortable.

Doctors can use it for cancer that has spread (advanced cancer) beyond the bowel or back passage (rectum). It can relieve symptoms such as pain in the pelvis or the rectum.

Radiotherapy can also help to relieve pain if the cancer has spread to other areas of the body, such as the liver, lung or bone.

Radiotherapy to relieve symptoms is also called palliative radiotherapy. 

You have treatment in the hospital radiotherapy department. You can have 1 or a few treatments. Each treatment takes a few minutes.

The radiotherapy room

Radiotherapy machines are very big. Some are fixed in one position, but others rotate around your body.  

Before you start treatment your radiographers explain what you'll see and hear. In some departments the treatment rooms have docks for you to plug in music players. So you can listen to your own music.

Photo of a linear accelerator

Before your treatment

Your radiographers help you get into position on the treatment couch.

The room is darkened and the radiographers line you up in the radiotherapy machine using laser lights. You will hear them saying measurements to each other to get you in the right position. 

Then they leave you alone in the room for a few minutes.

During the treatment

You need to lie very still. The machine makes whirring and beeping sounds. You can't feel the radiotherapy when you have the treatment. 

Your radiographers can see you and hear you on a CCTV screen in the next room. They can talk to you over an intercom and might ask you to hold your breath or take shallow breaths at times. They will ask you to raise your hand if you need anything but it is important to stay as still as possible. 

You won't be radioactive

Radiotherapy doesn't make you radioactive. It's safe to be with other people throughout your course of treatment.

Travelling to radiotherapy appointments

Tell the radiotherapy department staff if you prefer treatment at a particular time of day. They can try to arrange this.

Car parking can be difficult at hospitals. It’s worth asking the radiotherapy unit staff:

  • if they can give you a hospital parking permit
  • about discounted parking rates
  • where you can get help with travel fares
  • for tips on free places to park nearby

If you have no other way to get to the hospital, the radiotherapy staff might be able to arrange transport for you. But it might not always be at convenient times. Some hospitals have their own drivers or can arrange ambulances. Some charities offer hospital transport.

Side effects

Radiotherapy for advanced bowel cancer can make you tired. It can also make the skin in the treatment area go red and feel sore.

Specialised radiotherapy for cancer cells in the liver

Bowel cancer can sometimes spread to the liver. If this happens, your doctor might recommend a specialised type of radiotherapy treatment. There are 2 types:

Stereotactic radiotherapy

You might have this treatment if your bowel cancer has spread only to the liver and you can't have surgery.

A radiotherapy machine aims radiation at the cancer from different directions. This gives high doses of radiation to the cancer cells but only a small amount to the normal tissue around them. 

Selective internal radiotherapy (SIRT) 

For this treatment, your doctor puts tiny radioactive beads into the main artery that takes blood into the liver. The beads give off high doses of radiation to the cancer cells but cause little damage to the surrounding healthy tissue.

This treatment isn't available in all hospitals. You might need to travel to a specialist centre to have it. 

Last reviewed: 
17 Sep 2015
  • Metastatic colorectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
    E Van Cutsem (and others)
    Annals of Oncology, 2014. Vol 25, Issue 3

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