Kidney tumour ablation

This leaflet is designed to provide information to patients considering having a kidney tumour ablation procedure, their families and carers. It explains what is involved and the possible risks. It is intended to supplement any advice you may already have been given by your urologist, interventional radiologist or nurse specialist at Addenbrooke’s. If you have any questions about the procedure, please ask the doctor who has referred you for the procedure or the department which is going to perform it.

Key points

• Kidney tumour ablation is a treatment which uses heating or freezing to kill cancer cells
• Ablation is used to treat small kidney tumours (usually less than 4cm in diameter)
• It may also be used in patients with small renal tumours but who have comorbidities and are not candidates for major surgery. Co-morbidities are additional conditions, such as diabetes, that you may have as well as the kidney tumour.
• Occasionally, it is used as an option in patients with tumours in a solitary kidney or in patients with bilateral / multiple tumours due to a rare genetic condition (von Hippel-Lindau disease)
• The procedure is performed by an interventional radiologist using imaging to guide the treatment. You will require regular follow-up with scans to be sure that the treatment was successful and that there is no recurrence

Introduction

Kidney tumour ablation uses energy to cause destruction of cancer cells. The most common types of ablation therapy used in the kidney are radiofrequency (RFA) or microwave ablation (MWA) which both cause heat and thermal damage to destroy the cancer cells or cryoablation which involves the use of ice to freeze the tumours and destroy the tumour cells within a localised area.

Conditions treated by kidney ablation

Patients with kidney cancer localised within the kidney are suitable for this treatment. This type of treatment is generally used for small kidney cancers, usually less than 4cm in diameter. Several factors will be considered when deciding on whether ablation is the best treatment option for your tumour. These factors include the location of the tumour, the surrounding structures to the tumour, your overall health and age, how well your kidneys are functioning, local expertise and obviously your preference.

The decision to undergo kidney tumour ablation will be made by a multidisciplinary team that will include your referring doctor (usually a urologist or oncologist), the interventional radiologist (the doctor who performs the ablation procedure) and you, the patient. You will have had prior imaging, usually a CT scan, which will help guide the choice of treatment.

Generally, ablation is performed percutaneously, with the needle probes being placed directly through the skin and with no need for an incision. There is usually little in the way of blood loss and recovery times are quicker when compared to traditional surgery. The technique can be used as an alternative when a patient is not fit enough to undergo surgery. As ablation causes local tissue destruction, the damage to the surrounding "normal" kidney tissue is limited. The procedure can be performed either with local anaesthetic and sedation or with general anaesthetic.

What does this procedure involve?

The procedure involves placing probes (needles) through punctures in your skin (percutaneous approach). CT imaging is used to place the probes accurately into the tumour. These probes are then used to destroy the tumour by heating or freezing the abnormal tissue. A biopsy of your tumour may be taken at the same time.

The procedure generally lasts two to three hours with around a six hour recovery period afterwards. There may be some mild pain after the procedure, this is usually well controlled with pain relief tablets.

What are the alternatives to this procedure?

Partial nephrectomy (removal of the kidney) by robot-assisted laparoscopic surgery (commonly referred to as ‘keyhole’ surgery) or open surgery, observation of the lesion or total removal of the kidney by laparoscopic or open surgery. The various treatment options will have been discussed with you in clinic prior to the day of the procedure.

What should I expect on the day of the procedure?

Bring all of your medicines (including inhalers, injections, creams, eye drops or patches), a current repeat prescription from your GP and any cards about your treatment. Laxatives and painkillers may be required after your hospital stay - ensure you have appropriate supplies at home.

Please tell the ward staff about all of the medicines you use. If you wish to take your medication yourself (self-medicate) during your stay, then ask your nurse. Pharmacists visit the wards regularly and can help with any medicine queries.

The procedure is performed by a specially trained team led by a consultant interventional radiologist. Interventional radiologists have specific expertise in performing image guided procedures. The consultant in charge of your care and the interventional radiologist performing the procedure will have discussed your case and feel that this is the best option. However, you will also have the opportunity to express your opinion and if, after discussion with your doctors, you no longer want the procedure, you can decide against it.

The interventional radiologist will explain the procedure and ask you to sign a consent form. The procedure may be performed either under a general anaesthetic or using sedation. If you are going to have a general anaesthetic, the anaesthetic team will see you prior to the procedure and discuss the type of anaesthetic you will be given.

The procedure is usually performed in the CT scanning department or the X-ray angiography room.

You will be asked to get changed into a gown and a small thin tube (cannula) will be inserted into a vein in your arm so that you can be given any necessary medication during the procedure. You may be given some additional oxygen to breathe. You will be asked to lie on your front (or on your side if lying on your front is too uncomfortable) within the CT scanner.

What happens during the procedure?

You will be scanned again routinely as part of the procedure. This enables precise planning of the treatment and confirms the best means of access to the tumour. The area of skin to be used will be cleaned and sterile surgical drapes will be placed. Local anaesthetic is infiltrated into the skin to numb the area. A biopsy of the kidney may be taken prior to the ablation needle being placed. The needle is guided into the tumour using CT, sometimes in conjunction with ultrasound to ensure that it is correctly targeted. Due to the local anaesthetic, the placement of the needle should not be too uncomfortable. The ablation procedure is then performed. If the procedure is being performed under local anaesthetic a sedative is given prior to switching on the ablation machine. There may be need for further painkillers during the ablation process which are given through the cannula in the arm. A completion scan is performed to assess the immediate results of the ablation therapy and to ensure there are no significant complications.

What happens immediately after the procedure?

Although each patient is different, you should expect to be in the radiology department for two to three hours. From there you will be transferred to a recovery area and after recovery, to the ward. Your pulse and blood pressure will be monitored routinely. You will usually be kept in hospital for at least six hours, and sometimes overnight, to ensure that there are no significant complications with your recovery.

If you have any discomfort following the procedure, this can usually be managed by simple painkillers taken in tablet form. You should try to rest for about a week following the procedure and avoid strenuous exertion.

After you have been discharged, a follow-up consultation typically at 6 weeks after the procedure with the referring consultant will be arranged. You will have a further scan to evaluate the results of the ablation. This will typically be performed 4 weeks after the procedure.

Are there any side effects?

Outcomes after kidney cancer ablation are good, with almost comparable results to conventional surgery in small kidney tumours,. There is a risk of recurrent or residual cancer after ablation and you will have more scans to check for this as part of your follow-up.

Most procedures have a potential for side effects. You should be reassured that, although all these complications are well recognised, the majority of patients do not suffer any problems after a urological procedure.

Please use the check boxes to tick off individual items when you are happy that they have been discussed to your satisfaction:

Common (greater than one in 10)

☐ Pain requiring analgesia post procedure

Occasional (between one in 10 and one in 50)

☐ Bleeding around the kidney, not requiring further treatment

☐ Need of further therapy for cancer

☐ Need for re-biopsy of the tumour at a later stage

Rare (less than one in 50)

☐ Anaesthetic or cardiovascular problems possibly requiring intensive care admission (including chest infection, pulmonary embolus, stroke, deep vein thrombosis, heart attack and death)

☐ Significant bleeding requiring blood transfusion or further treatment

☐ Involvement or injury to nearby local structures (blood vessels, ureter, spleen, liver, lung, pancreas and bowel) requiring further treatment

☐ Infection or abscess requiring antibiotic treatment or drainage

☐ Seeding (recurrence) of tumour along needle track

☐ May be an abnormality other than cancer on microscopic analysis

Hospital-acquired infection (overall risk for Addenbrooke’s)

☐ Colonisation with MRSA (0.01%, two in 15,500)

☐ Clostridium difficile bowel infection (0.02%; three in 15,500)

☐ MRSA bloodstream infection (0.00%; 0 in 15,000)

(These rates may be greater in high risk patients, for instance those with long-term drainage tubes, after removal of the bladder for cancer, after previous infections, after prolonged hospitalisation or after multiple admissions).

References and Sources of evidence

CIRSE guidelines on percutaneous ablation of small renal cell carcinoma – CVIR 2017 40(2):177-191

Privacy and dignity

Same sex bays and bathrooms are offered in all wards except critical care and theatre recovery areas where the use of high-tech equipment and/or specialist one to one care is required.