Image guided ablation of kidney tumours

What is an image-guided renal tumour ablation?

Image-guided ablation is a method of treating cancers within the kidney without conventional surgery. It allows one or more cancers to be treated with minimal injury to the remainder of the kidney. The procedure uses a specially designed needle which either cools or heats the cancer cells or destroys them with electrical pulses.

How is an image-guided renal tumour ablation performed?

This operation is performed in the CT room under a general anaesthetic.

Using CT imaging, special needles are placed into the cancer. The number of needles required is determined by the size of the cancer.

Anaesthetic

This operation is carried out under a general anaesthetic.

Your fitness for a general anaesthetic will be assessed in the pre-assessment clinic.

Operation

Once you are asleep, the Interventional Radiologist passes special needles through a small puncture in the skin and positions it within the cancer, using a CT scanner for guidance.

The needle is attached to a generator which delivers the energy to destroy the cancer. The energy it delivers will depend on the size and location of the cancer. The energy source can be heat, ice or electrically-based. The actual treatment usually takes about 30-40 minutes but the whole operation may take several hours depending on how many needle placements are required

Consent

You will meet the interventional radiologist in the interventional oncology clinic to discuss image-guided renal tumour ablation. The operating interventional radiologist will explain this to you in more detail, along with the risks and intended benefits before you provide your permission to proceed with the operation via a signed consent form.

What are the risks?

Serious complications are uncommon. Each individual patient has their own risk factors that will be discussed during the first appointment. Your anaesthetist will also discuss with you the risks of having a general anaesthetic for this operation.

Common risks

• It is not unusual to develop a flu like sensation known as “post-ablation syndrome” in the days following ablation which is related to the death of the cancer cells.
• Small risk of infection in the treated area, you will be given antibiotics if appropriate before the procedure to try and prevent this.
• Small risk of bleeding, very occasionally patients may need another procedure to stop the bleeding or a blood transfusion. If you take blood thinning medication, the nurse will discuss with you when to stop taking them, if required for this operation.
• We are all exposed to low levels of natural radiation as part of our everyday lives and medical x-rays like CT scans give an extra dose of radiation. Radiation can increase your chances of developing a new cancer many years or decades after the exposure. The chances of this happening to you as a result of this procedure are about 0.3%, which is low compared to the natural risk of 50%. In some very rare situations, you may experience some reddening of your skin in the area that was treated. If this happens, please contact our team for clinical advice. It is important to remember that your doctor thinks that the benefits of this procedure outweigh any risks from the radiation, and we will make sure that the amount of radiation used in your operation is as low as possible.

Less common but serious risks

• In some patients the lung or bowel may be close to the site of treatment, this risks damage to these structures. Occasionally additional manoeuvres at the time of ablation are required to push these structures away to try and prevent damage.
• Rarely more serious injuries or death may result from the treatment. The risk of such a complication is estimated to be about 1% or 1 in 100 treatments.
• Rarely, blood clots could form within the veins called ‘’Deep Vein Thrombosis’’, where you may need to be prescribed blood thinners for.

Are there alternative investigations / treatments?

The alternative treatments to ablation include observation, and surgery (such as removal of the whole or part of the kidney). The risks and benefits of the different treatments would have been considered by your cancer specialist before referring you for an ablation, but we can review these alternative options with you when you meet our team.

In general, younger patients and those with larger tumours are offered a total nephrectomy (removing the whole kidney) with other patients being offered partial nephrectomy. Not all cancers are suitable for partial nephrectomy so you may not have been offered this. Ablation is especially useful in patients with single kidney, multiple cancers, poor kidney function or those with other medical problems.

How well does it work?

In general, ablation is most likely to be successful if the cancers are smaller (less than 4cm). With cancers less than 4cm, the long-term outcome of image guided renal ablation in our centre has sucess rates ranging between 96%-100% at 10 years. This is similar to surgery in our institution.

What if the cancer grows back?

In a small number of cases (5-10%), the cancer may not be successfully ablated. The treatment can be repeated, or your cancer specialist may suggest an alternative treatment.

What to expect from this operation?

Admission

You will be admitted on the morning or afternoon of your procedure unless you have any co-mobilities that will require you to be admitted the day before. On the day, the ablation team will consist of:

• Consultant Interventional Radiologist
• Clinical Nurse Specialist (CNS)
• CT radiographers
• Consultant Anaesthetist
• Anaesthetic Operating Department Practitioner

Pre-operative preparation

You will attend the pre-assessment clinic for an anaesthetic assessment and investigations before your operation, to include blood tests and ECG.

Pre-assessment will take your medical history and review your medications. They will advise you if you need to omit any of your medication on the day or prior to the operation. If you are taking blood thinners, instructions to stop this medication may be given to you.

You will be assessed for Obstructive Sleep Apnoea (OSA). Sleep apnoea is when your breathing stops and starts when you sleep; this may require you to have further investigations. Please bring your CPAP machine during your admission, if you normally use one at home.

You will be assessed for Methicillin-resistant Staphylococcus aureus (MRSA) and you will be given an anti-microbial body/hair wash and nasal cream. This will be discussed during pre-assessment, and you will receive instructions on how to use them.

Carbapenemase-Producing Enterobacterales (CPE) are bacteria that usually live harmlessly in the gut of humans. You will be screened for this, which usually involves taking a rectal swab/stool sample.

You will receive a letter from the hospital with your admission date, ward, and instructions for fasting prior to the operation.

Recovery

You will be transferred to theatre recovery following your operation. You may wake up with a sore throat, which is usually caused by the breathing tube that was placed in your throat while you were asleep.

It is common to have haematuria, which is characterised by a pink-tinged urine caused by presence of blood, for a couple of days after the procedure. This is a normal finding that results from the needles placed into the kidney/s.

Aftercare

Once back in the ward, the nursing staff will continue to monitor you regularly. IV fluids and pain relief will be administered as prescribed by the doctor.

Blood tests will be performed the morning after your operation to review your full blood count and renal function. Most patients are discharged in the next few days.

Care at Home

We would advise that someone is at home with you the first night after discharge. After your operation, you may still experience pain or nausea, which can be managed by medications. Please see some of our recommendations below:

• Hydration: drink 2-3 litres of water a day. Adopt this as a lifelong habit as it helps to keep your kidneys healthy.
• Exercise: avoid lifting heavy items and other strenuous exercise for at least two weeks.
• Driving/travel: you should refrain from driving or flying until you feel well enough. It is your responsibility to make sure you are fit to drive or fly.
• Medicines: you will be advised about restarting your medications before discharge. It is normal to experience mild pain and discomfort, continue your regular painkillers like paracetamol for the first week and reduce as pain decreases. If your pain and your painkillers are not working, please contact your GP to review your medications.
• Work: you should normally be able to return to work after 1-2 weeks, although some patients may require a longer recovery period.
• Follow up: arrangements will be made for the Interventional Oncology CNS team to contact you after discharge via telephone to carry out remote follow-up after your operation. You will also be booked to attend follow-up imaging, usually via MRI (two-three scans over the first year) and a CT scan annually.

Contact information

We hope some of your questions have been answered by this leaflet. If there are any questions you would like to ask before you come for your operation, please get in touch.

Or attend your nearest A&E department