Cryotherapy, Cryosurgery, or Targeted Cryo-ablation of the Prostate (TCAP) involves inserting, under ultrasound guidance, a number of probes into the prostate gland. A gas (e.g. argon) 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. An ice ball is formed which destroys the tissues and tumour in close proximity to the tips. By suitable positioning of these probes, the tumour or the whole prostate is treated. The process also involves the use of a second gas (e.g. helium) to thaw the area, and several freeze/thaw cycles may be used. Additional probes are used to measure the temperature so as to ensure adequate control. The illustration shows probes inserted into the prostate.
Cryotherapy is normally considered by most urologists only as an option when radiotherapy has failed but the cancer is still in the prostate. Cryotherapy is not suitable for those with an over-enlarged prostate.
The treatment requires close teamwork between radiologists and urologists, who use transrectal 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 2 - 3 days after treatment but with a catheter in place, which will usually remain for two weeks. PSA levels should gradually return to normal after treatment.
Note: There is no long-term data on the effectiveness of this treatment. It is only available at a few centres in the UK.