Information for Patients


Traditional therapies for cancer include surgery, radiotherapy and chemotherapy. Recent advances are adding another tool to the anti-cancer arsenal - thermal ablation whereby tumours are heated or cooled to temperatures that cause the tumour cells to die. Thermal ablation has been studied in many forms, including microwave, laser and high-intensity focused ultrasound. Radiofrequency thermal ablation or radiofrequency ablation (RFA) has emerged as the most commonly used technology with microwave currently in second place, for thermal ablation of bone, liver, kidney, lung, and soft tissue tumours. Cryoablation is most commonly used in bone and kidney tumours.

What is Thermal Ablation?

Images (usually ultrasound and/or CT computed tomography) are used to guide the introduction and positioning of needle electrodes/probes or antennae through the skin and into a tumour. Once correctly positioned, power is applied and this causes heating or cooling around the tip of the needle. The needles are small 1 - 2 mm in diameter so there is no incision or wound and either no mark or a tiny mark is left on the skin. In all but the smallest tumours it is usual to perform multiple treatments to ensure maximal tumour kill. It is also advisable to heat/freeze some of the apparently normal tissue around the tumour as we know that although the scans show normal tissue there is often microscopic tumour in this area.

What types of tumours can be treated?

The most common indication, the greatest experience and the most widely studied is the treatment of liver tumours either primary liver tumours or tumours that have spread from another site e.g. the bowel, breast or neuroendocrine tumours. The next most common indication is for lung tumours. Thermal ablation is also very effective in kidney cancer and for the treatment of small benign bone tumours such as osteoid osteomas. Although ablation can be performed and has been performed in other sites these indications are less common.

What are the indications?

Number, size, location and type of tumour are all important variables. Thermal ablation is a localised destructive technique and this limits the number and the size of the tumours that can be treated.

Each patient is an individual and the treatment plan needs to be tailored to that person. The following criteria represent broad guidelines rather than strict rules.

  • For colorectal or breast secondaries
  • solitary tumours smaller than 7 cm
  • as many as 5 tumours but only if they are smaller than 5 cm
  • as many as 9 tumours but only if they are smaller than 4 cm
  • For primary liver tumours the optimal criteria are different
  • 1 tumour smaller than 5 cm
  • or 3 tumours smaller than 3cm.
  • IN THE LUNG we will treat:
  • < 5 (preferably < 3) tumours/lung up to 3.5 cm.
  • Usually we treat one lung at a time.
  • Larger tumours can be treated in conjunction with radiotherapy or systemic chemotherapy.
  • we will treat tumours up to 5 cm.

We will treat most osteoid osteomas although some locations are difficult.

Some tumours are easier to reach with the needles e.g. peripheral (closer to the skin) tumours are easier to reach than central tumours. As heating/freezing is not a specific destructive process it is important that any vulnerable tissue or structures lying next to the tumour are displaced away from the needles to prevent injury. If these structures cannot be displaced or protected by cooling then thermal ablation may not be advisable.

This is a developing technology, there is on-going research in several areas aimed at improving our efficiency. Therefore these guidelines will change

How effective is this form of treatment?

Ablation is very effective at eradicating small tumours. In secondary tumours confined to the liver the survival data is better than would be expected without treatment or with systemic chemotherapy. Tumours occasionally regrow at the site of a treatment and are more likely to grow back if there is a nearby blood vessel as flow in the blood vessel protects the tumour from the effects of heat/cold. If the tumour recurs then further treatment can be given and in this way although the tumour may not be eradicated it can be controlled for a period of time.

How is it performed?

We recommend general anaesthesia for the treatment of metastatic liver disease. Small liver treatments can be performed under conscious sedation and we use this technique particularly in patients who cannot undergo general anaesthesia. Most lung and kidney ablations are performed under conscious sedation, although longer more complex treatments require general anaesthesia and some patients elect to have a general anaesthetic. We recommend a combination of US and CT and if possible, US/CT co-registration to guide and monitor the procedure. Small treatments can be performed as a day-case but most often patients stay one night in hospital.

What about after-care?

Many patients experience some discomfort or pain at the site of the treatment and therefore we routinely prescribe pain tablets for a few days. A low grade fever and a feeling of malaise or being "under the weather" is also common and we advise our patients to "take it easy" for the first few days with no strenuous activity.

What to do next if you wish to be considered for thermal abalation?

Discuss the possibility with your doctor. If there is uncertainty as to your suitability you could consider requesting that the ablation consultant in your area reviews your case or that you meet with them for a consultation.

Please use the Micro Form at the top right of this page to contact us directly regarding information for patients.Using this form will help us deal with your request swiftly.

Micro Form

Use this form to contact us directly regarding information for patients.

Please ensure that you fill in all the required fields before sending.

Micro Form