What is Cryotherapy?
Cryotherapy, Cryosurgery, or Targeted Cryo-ablation of the Prostate (TCAP) involves inserting, under ultrasound guidance, a number of probes into the prostate gland. Argon gas is passed down these probes under pressure and, at the tips, it is allowed to expand and flow back down other channels of the probes. Ice balls are formed which destroy the tissues and the tumour in close proximity to the tips. By suitable positioning of these probes, either the tumour itself or the whole prostate gland can be treated. The process also involves the use of a second gas (helium) to thaw the area; two (or sometimes more) freeze/thaw cycles may be used. Additional probes are used to measure the temperature so as to ensure adequate control.
Who is it for and what is involved?
Cryotherapy is normally considered by most urologists only as an option when radiotherapy has failed but the cancer is still found in the prostate. As well as targeting the whole prostate, it can now treat small areas identified on a special mpMRI scan. Cryotherapy is not suitable for those with an over-enlarged prostate.
The treatment requires close teamwork between radiologists and urologists, who use trans-rectal ultrasound for the insertion and guidance of the five to eight needles. This is done under general or spinal anaesthetic, lasting about 1–2 hours. The patient will normally be discharged from hospital within 24 hours of treatment but with a catheter in place, which will usually remain in for two weeks. PSA levels should gradually drop to an acceptable level after treatment.
Ice balls forming in the
prostate after insertion
of the needles
The development of refined MRI and biopsy techniques has made it possible to target small areas of cancer within the prostate. This minimises side effects and can be more easily repeated. Focal treatment is only used in clinical trial centres.
Advantages and disadvantages
Note: There is no long-term data on the effectiveness of this treatment. It is only available at a few centres in the UK and is only obtainable on the NHS in the context of a clinical trial.