CT (Computed Tomography) Ablation

Why do I need an ablation?

Previous investigations have demonstrated a tumour that requires treatment using either heat (Microwave Ablation) or ice (Cryoablation) to destroy it.

What is an ablation?

Microwave ablation involves the use of heat to cause destruction of cancer cells. Small needles are inserted into the tumour. The needles heat the adjacent tissue and cause thermal damage and eventual destruction of the cells.

The needles used are 1 to 2 mm in diameter and therefore no large incision is required for their insertion. Once the needle is in the correct position, microwave energy is passed through the needle and into the surrounding tissue causing it to heat up and destroy the tumour cells. The effect is localised; however, the needle can be moved to a number of different positions to ensure good coverage of the tumour and its surrounding area.

Cryo ablation, involves the use of ice to freeze tumours. The ice used is at a temperature of less than -40°C and provides a very efficient means of destroying tumour cells in a localised area.

Much like microwave ablation, cryoablation involves inserting small needles into the tumour under imaging guidance. The needles used are about 1.5 mm in diameter.

Where will the ablation be done and who will carry it out?

The ablation will be done using a CT scanner within the Radiology Department. The CT scanner uses X-rays to produce highly detailed image slices of the body, which are used to guide a fine needle into the tumour ready for the ablation to take place.

An Interventional Radiologist (a specialist radiology doctor who uses minimally invasive, image-guided techniques to diagnose and treat a wide range of diseases) will carry out the procedure alongside an anaesthetist who will monitor you during the procedure. They will be assisted by a radiology nurse and a radiographer.

How do I prepare for the procedure?

A pre-assessment conversation is required before the procedure. This may take place over the telephone or you may be sent an appointment to attend a clinic in the hospital. Please have a list of all your medications available.

You will need a blood test before the procedure to check that you do not have an increased risk of bleeding following the ablation, and that your kidney function is satisfactory. The pre-assessment nurse will discuss this with you.

On the day of your procedure, do not eat anything for 6 hours before your appointment.

Some blood-thinning medications may need to be stopped before the biopsy (we will let you know if this is the case for you) but please continue to take any pain or blood pressure medication as normal.

Report to the area stated on your appointment letter (this may be the Radiology/Imaging Department or a Ward), where you will be asked to change into a hospital gown.

A member of the Anaesthetic team will meet with you at this stage to discuss what is involved and then the radiologist will discuss the procedure with you in full.

You will need to stay in hospital overnight, so please bring an overnight bag with you.

You will not be able to drive after the procedure and will need to arrange transport home.

Can I bring a relative/friend?

Yes, but for reasons of safety they cannot join you in the CT scanning room.

Giving your consent (permission)

We want to involve you in the decision about your care and treatment. The radiologist will explain the procedure to you and give you the opportunity to ask questions. You will then be asked to sign a consent form. This states that you agree to the procedure and understand what it involves. You may withdraw your consent at any time.

The Radiology Department plays an important role in the training of future healthcare professionals. The part patients play in this is vital in ensuring we produce the right quality of healthcare professionals for the future. If at any time you would prefer not to have students present, please inform the team looking after you. This will not impact on your care in any way.

What happens during the procedure?

You will be taken into the scanning room and an anaesthetist will give you a general anaesthetic so that you will be asleep during the procedure. You will then be moved onto the CT scanning bed and put into a position which provides the radiologist with the most accessible route to your tumour.

A CT scan will then be performed to locate the tumour.

Using this scan, the point of entry for the needles is marked on the skin which is then cleaned with antiseptic solution.

A biopsy of the area may be taken prior to the needles being inserted. The needles are then guided into the tumour, using CT to ensure they are correctly targeted.

The ablation will then begin, with possibly several areas being targeted and the needles being manipulated several times. A completion scan is then performed to assess the immediate results of the ablation therapy.

Will the procedure be uncomfortable?

The ablation is performed under general anaesthetic so you will not feel anything. Following the procedure, there is often a mild ache and occasionally more significant pain; this can be managed with pain relief.

What are the risks involved?

The procedure is normally well tolerated, and complications are rare. Most people go home the day after the procedure.

The exact risks depend on the location of the ablation:

• Pain and bruising; this should go after a few days.
• Infection; this is rare but may present as redness, swelling, fever and chills. If this happens you will need to seek medical advice.
• Haematoma (blood clot) which may cause some swelling and pain. A cold compress and simple pain relief such as paracetamol are normally effective.
• Bleeding requiring intervention - the area being ablated or an adjacent blood vessel may rarely bleed enough to need a further procedure. This is usually a minimally invasive procedure to stop the bleeding, very rarely is a surgical procedure required.
• Damage to skin/muscle/nerves - rarely the ablation zone extends into nearby structures; this can lead to longer term issues with pain and skin healing.
• Damage to surrounding organs - whilst every care is taken to limit the area ablated, on rare occasions the bowel or adjacent organs can be damaged. Very rarely this may require an operation.
• Pneumothorax - to access the tumour occasionally needles are inserted intentionally or unintentionally across the space around the lung. This can lead to air leaking into this space and a deflation of the lung and is usually straightforward to treat with a small plastic tube called a chest drain. However, this may delay discharge.
• Very rarely the tumour cannot be fully treated, in this case another attempt can be made or the appointment rebooked.

CT scanning does involve X-rays and has the usual risks associated with ionising radiation. The amount of radiation is equal to the natural radiation we all receive from the atmosphere over a period of about 3 years.

There are also risks associated with an anaesthetic. These are typically very low but will depend on other health issues. These risks will be discussed in detail at your pre-operative assessment and again on the day by the anaesthetist.

How long will the procedure take?

Every patient is different, so it is not possible to give a definite timeframe. Following the ablation, you will be looked after in the theatre recovery area by a recovery nurse who will observe you for a short while. If you feel well, you will then be transferred to a ward for continued care and observation for 24 hours.

We recommend that someone picks you up and you rest at home for 48 hours to let the site of the procedure heal. You must not drive until fully recovered from the anaesthetic. Your car insurance may not be valid if you have had a medical procedure.

Dependent on the location of the procedure, we may recommend that you refrain from heavy activity for a week.

Are there any side effects?

Most patients experience some discomfort following the procedure and this is usually managed by simple pain relief taken in a tablet form.

Do I have to have this procedure or is there an alternative?

You do not have to have an ablation. It is possible just to monitor the abnormality with scans but this risks the abnormality growing or spreading and may delay treatment which might lead to worse outcomes. There are sometimes surgical options - these will be discussed with you in clinic.

Should I still take my regular medication?

Yes, but you may need to stop any blood thinning tablets. If you take any of the following medications please contact the radiology nurses for advice; Aspirin, Clopidogrel, Warfarin, NOACs (Apixaban, Rivaroxaban, Dabigatran) Fondaparinux.

Checklist

If you are taking ‘blood thinning’ medication, please telephone the radiology nurses for instruction on when to stop and restart them.

If you hold a Health Passport or require additional support for this procedure, please let us know via the telephone number on your appointment letter so we can discuss how best to support you.

Interpreters

If you need an interpreter for the day of your procedure, please contact the department so we can try to arrange this.

Cancelling your appointment

If you are unable to attend your appointment, we would be grateful if you could contact us as soon as possible. We can then offer your appointment to another patient and arrange another date and time for you.

If you have had diarrhoea and/or vomiting, please cancel your appointment unless you have been free of symptoms for 48 hours. Please ring the Interventional Appointments Officer on the number shown on your appointment letter, between 9:00am and 4:30pm, Monday to Friday.

Notes

Hopefully, this information has answered most of the questions you may have but remember this is only the starting point for discussion about your treatment. Make sure you are satisfied that you have received enough information about the procedure in advance. Please feel free to contact your consultant or the Radiology department to discuss any queries you have before the procedure.

There is a section within the PDF below, designed for you to make notes about anything you would like to ask during these discussions.

Contact information

We are pleased that we can offer state of the art technology for diagnosis. However, radiology equipment needs constant updating and there is a charitable fund for this. If you would like to donate, please send a cheque to the appropriate address below. Cheques are payable to GHNHSFT.

Please send your donation to:

Business Manager, Dept of Radiology (Imaging 1), Gloucestershire Royal Hospital, Gloucester GL1 1NN