SABR to the abdomen

Stereotactic ablative radiotherapy (SABR) to the abdomen is an effective way of giving radiotherapy to treat cancer within the abdomen. This includes the liver, pancreas, adrenal glands, bones, or abdominal lymph nodes. Your doctor will explain why you are receiving this type of treatment.

Radiotherapy uses radiation (high energy X-rays) delivered to a specific area to treat cancer and other conditions.

SABR uses smaller beams and more of them, and they are given from different directions so they can be more focused on the area that needs treatment. This means that less surrounding tissue is affected.

You and your doctor have decided that this type of radiotherapy would be the appropriate treatment for you. You will need to sign a consent form agreeing to have treatment. You will also be asked to confirm this consent verbally (spoken) on the day of your planning scan.

When recommending radiotherapy, your doctor will have thought about the risks and benefits of the treatment. They will also talk to you about these. Although there will be side effects, we feel that the benefits for you will outweigh the risks.

You might decide that you do not want to have radiotherapy. This is an option for you to think about. In this case, you might want to talk again with your doctor and let them know what you have decided.

You can ask for a second opinion on your diagnosis or treatment at any time during your consultation or treatment process. Please speak to your clinical oncologist or GP for information about how to do this.

Benefits of SABR

The main benefit of using SABR to the abdomen, compared to standard radiotherapy, is the much shorter overall treatment time. Most patients will receive 3 to 5 sessions (also known as fractions) over 5 to 10 days with SABR, but you can have up to 8 sessions. This compares to 25 fractions over 33 days with standard radiotherapy.

Who looks after you during your treatment

A consultant clinical oncologist will be in charge of your care. Clinical oncologists are doctors who are trained in the use of radiotherapy and chemotherapy. They are supported by a team of specialist registrars, therapeutic radiographers, nurses and administrative staff.

Therapeutic radiographers are specifically trained to plan and deliver the radiotherapy. They provide support and advice on radiotherapy side effects and how to manage them. The radiographers will have day-to-day responsibility for you while you are receiving radiotherapy.

Side effects

Any side effects of radiotherapy are usually only in the part of your body being treated.

Skin changes

It is common for the skin in the treatment area to react to the radiation. The skin might become dry, red and itch for 1 to 2 weeks after treatment ends. This can cause the skin to blister and the area to get moist. If this happens, the skin will fully heal after treatment has finished.

To reduce the risk of this happening, we suggest moisturising. This will help your skin to cope better with the treatment. You can continue to use your usual moisturiser. After treatment, apply the moisturiser sparingly 2 times each day, or more often if your skin is very itchy.

Other side effects

During or shortly after SABR treatment, you might have other side effects, including:

  • tiredness
  • nausea (feeling sick)
  • vomiting (being sick)
  • tummy (abdominal) ache
  • indigestion (dyspepsia)

Your oncologist will talk to you about these side effects during the consent appointment, and how to manage them.

Your oncologist will also speak to you about any side effects that you might have later on. This can happen weeks to months after you have had SABR treatment.

They will warn you about any rare, but potentially serious side effects that might happen after your treatment. These will include damage to the liver, bowel or kidneys.

If you are feeling unwell on treatment days, let your treatment team know. The acute oncology assessment unit will provide emergency medical care for any side effects of treatment or problems relating to the cancer itself. This service is available Monday to Friday, 9am to 6pm, phone: 020 7188 3754. Emergency contact details will be provided for out-of-hours problems.

We want to involve you in decisions about your care and treatment. If you decide to go ahead, you will be asked to sign a consent form. This states that you understand what it involves and agree to have the treatment.

If you would like more information about our consent process, please speak to a member of staff caring for you.

Before radiotherapy starts

If you are able to get pregnant, and are under the age of 60, you will be asked to confirm your pregnancy status before the first planning session starts. It is very important that you are not, and do not become, pregnant while having radiotherapy planning and treatment.

If you think you might be pregnant at any time during your course of treatment, please tell your clinical oncologist or radiographer immediately. If necessary, please speak to your GP about contraception methods suitable for use during radiotherapy.

Planning the treatment

Fiducial markers

You might have small metal markers placed in or around the tumour. They are sometimes called fiducial markers. The markers help find the exact location of the tumour to make sure the treatment is given in exactly the right place.

You will be asked to sign a separate consent form for the fiducial markers which will be inserted by the interventional radiology team. This is usually done a week before the radiotherapy treatment planning begins.

The markers are about the size of a grain of rice and are put in using a needle during a CT scan or ultrasound scan. The doctor gives you a local anaesthetic injection to numb the skin so it does not hurt. They might also give you a mild sedative to make you feel sleepy. The doctor makes a small cut and puts a needle through the skin over the tumour. When the tip of the needle is in the right place, they release the marker. Usually 2 or 3 markers are needed.

Radiotherapy planning

Your specialists will use the scan and mapping information to decide where to deliver the radiotherapy. This is called the target for radiotherapy. It will involve a long visit to the radiotherapy department where you will have different procedures.

On the day you come in for the planning scan you might need to fast for 2 hours before the appointment time. This is to make sure that your stomach is in the same position for the scan and treatment.

If you are asked to fast, you will also need to fast for 2 hours before your treatment appointments.

You will go to the mould room where you will have a vacuum bag made. This is to help you to stay in the same position for planning and treatment. The vacuum bag is like a bean bag, and it moulds around your body. We remove air from a sealed bag of pellets, which makes the bag mould itself to your shape. This takes about 20 minutes.

You will need to lie on the vacuum bag while you have a planning CT scan. The scan is painless, but a small needle (cannula) will be placed in your arm to give an injection of CT contrast. This helps us take more detailed images during the scan. The scan will take images of your abdomen and will measure your breathing cycle. It might be necessary to use a compression device to press down on your abdomen and restrict your breathing. This will not stop you from breathing. You might be asked to hold your breath during the scan.

The information from the scan is used to see the exact part of the abdomen that needs to be treated. This procedure can take up to 1 hour. As part of the pre-treatment planning process, the radiographers will need to take some measurements and put small, permanent marks on your skin using ink and a small needle. These reference marks are used to position you at each treatment appointment.

End-expiration breath hold (EEBH)

EEBH is a breathing technique where you hold your breath during your planning CT scan and your radiotherapy treatment.

We spend most of our breathing cycle in the exhale phase (breathing out). As the area that needs treatment is not moving when you are holding your breath, we can reduce the amount of surrounding tissue that receives radiotherapy. You do not have to prepare to do EEBH, but you might want to practise it.

Take a slightly deeper breath than usual, then exhale (blow all the air out), and hold for 20 to 30 seconds before you breathe again.

The radiotherapy team will let you know at your CT scan appointment, if you will need a breath-hold scan.

Throughout this process, the SABR team will be available to answer any questions you have.

Before you begin your treatment, the SABR team will need to create a personalised radiotherapy plan for you. All of your scans will be entered into a planning computer. The doctor will identify the area that needs to be targeted with the treatment, and will also identify important organs that can only receive a small dose of radiotherapy.

First day of treatment

You will be asked to come in for a practice treatment session 2 to 3 days before the start of your treatment. The therapeutic radiographers will set you up into the treatment position and take a scan. This is to check everything is as expected before you officially start treatment.

The SABR treatment is delivered in 3 to 8 treatments, on alternate days (1 day with no treatment between each day with treatment). Each appointment will last about 45 minutes. The treatment is given by a machine called a linear accelerator. This is a type of X-ray machine, and is sometimes called a ‘linac’. The staff who operate it are therapeutic radiographers.

In the treatment room you will be asked to lie on the treatment couch on your vacuum bag. The radiographers will make sure that you are in the same position as you were for your planning scan. When you are in the correct position, they will leave the room and the treatment will start.

You might be given breathing instructions and asked to hold your breath, or you might be able to breathe as normal. This will depend on the radiotherapy treatment that you will be receiving.

You will be asked to keep still for the treatment. You will be closely monitored on the closed circuit TV cameras at all times, and will be able to communicate with the team using the intercom.

The machine will move around you, but will not touch you. The radiographers might come into the room to re-position the machine. They will tell you what is going on throughout the treatment. The treatment is painless and you should feel no different immediately after treatment.

Follow-up appointment

You will be seen by your oncologist 2 to 4 weeks after treatment. They will check for any side effects and speak to you about how you can manage these.

Resource number: 5430/VER1
Last review: September 2023
Next review: September 2026

Trusted Information Creator. Patient Information Forum

Contact us

If you have any questions about SABR for the abdomen, please contact:

Radiotherapy reception (Guy's), phone 020 7188 7188, extension 57542 or 57569

Radiotherapy reception (Queen Mary's Hospital), phone 020 7188 0770

For radiotherapy bookings, phone 020 7188 3160

Acute oncology assessment unit, phone 020 7188 3754

Outside normal hours, please contact the main switchboard, phone: 020 7188 7188 and ask for ‘operator’ or press 0. Ask for the on-call clinical oncology registrar.

If you’re concerned please go to your nearest emergency department (A&E).

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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