Cryoablation treatment for prostate cancer -
The big freeze!
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| John Davies Consultant Urological Surgeon |
JH Davies, Consultant Urological Surgeon at The Royal Surrey County Hospital and St Lukes Cancer Centre, Guildford, explains the history of Cryosurgery and why RSCH has become a centre of excellence for the procedure the UK.
The use of ice in medicine is not a new concept. Ice vapour was used to treat some forms of breast cancer as early as the 19th century. At temperatures of less than 0C, ice crystals form within living tissue. This causes the disruption of the cell wall and release of toxic materials causing "cell shock" and finally death of the cell. Cancer cells are killed if the temperature is taken to below -40°C.
Later, in the 1960's, liquid nitrogen was used to freeze the prostate gland in men with advanced prostate cancer. However, although able to freeze tissue to below -100°C, the use of liquid nitrogen did not gain acceptance in urological practice due to the severe complications caused by the lack of control of temperature and the inability to monitor the freeze process.
It wasn't until the 1990s that the use of specially designed temperature needles and accurate visualisation of the prostate during treatment by trans-rectal ultrasound enabled safer freezing of the prostate. Liquid argon is colder than nitrogen allowing temperatures within the prostate to be taken to -140°C and peripheral temperatures to -40°C. Cryoprobes needles 2 mms in diameter allow argon gas to circulate and freeze the prostate. Helium gas is then pumped into the cryoprobe allowing rapid thawing and a safer control of the prostate.
The use of such technology allows men with either prostate cancer localised to the gland or men who have received radiotherapy for prostate cancer which recurs, to receive cryoablation in a minimally invasive manner, often as a day case procedure. Results indicate this treatmentcan be as effective as radiotherapy, brachytherapy and radical surgery in curing prostate cancer localised to the gland. In those men who have recurrent prostate cancer post radiation it offers a chance of a cure instead of palliative hormonal therapy or a major salvage operation.
The Royal Surrey County Hospital was the first hospital in Europe to offer argon/helium technology for prostate cancer treatment. The cryo programme started in 1999 with a visit by John Davies to Columbia Presbyterian Hospital in New York. Subsequently, a team of American Surgeons including Professor Douglas Chinn, visited Guildford to help launch the programme. This work was supported by the Prostate Project who provided the vital ultrasound facility for cryo and also supported the purchase of the delicate finely engineered cryoprobes for some local patients.
The use of cryosurgery for prostate cancer allows a minimally invasive treatment to be used which can be repeated if necessary, unlike radiotherapy or radical surgery. A typical patient may be admitted on the day of the operation which can be carried out under a local or general anaesthetic. Men can be discharged the same day or the following morning.
To date, 58 men have been treated in Guildford using cryoablation. The majority have received previous radiotherapy which has failed. However, men have also been treated who elected not to undergo radiotherapy treatments or major surgery.
The NHS, via the National Institute of Clinical Excellence (NICE), is currently evaluating cryoablation. Three other centres in the UK have commenced such treatments.