Prostate focal therapy
For many men with newly diagnosed prostate cancer focal therapy is now an option. Focal therapy is suitable for men with disease confined to one area of the prostate rather than larger more widespread tumours. Focal therapy has become possible due to improved imaging and localisation of disease with target and mapping prostate biopsies. The aim of focal therapy is to destroy areas of cancer and preserve normal areas to reduce side effects. Typically focal therapies are given as day case procedures, require brief periods of post operative urethral catheterisation and cause sexual and urinary side effects less frequently and less severely than conventional whole gland therapies. Mr Dudderidge is one of the UK’s leaders in focal therapy. He is a member of the UK Focal Users Group and recruits to the INDEX Lite study and FORECAST study evaluating focal therapies.
For more information, visit the Focal Therapy User Group.
What is Focal HIFU?
High-intensity focused ultrasound (HIFU) uses the energy of focused sound waves to generate heat within tissues and kill cancer cells within treated tissues. HIFU is planned based upon multi-parametric MRI scans and biopsy results. Typically half the prostate is treated. Patients are usually treated as day cases and they keep a catheter in for 1 week. Sexual and irinary side effects are usually mild and serious risk are very low.
Results of focal HIFU have only 5 year outcomes reported which is too short term to give representative figures. Furthermore its difficult to compare the results in this study to the results of surgery or radiotherapy as the case mis is likely to be different and follow up much longer. The early report from the UK Focal Users group presented 5 year outcomes on 625 cases, 81% of which were intermediate risk disease. After treatment 98% were pad free meaning very little incontinence. 86% maintained their erections. 2 patients experienced a fistula (damage to the rectum causing a leak of urine into the rectum) one of which healed spontaneously with a catheter, the other required surgery to repair the damage. 20% of men required pretreatment with HIFU. 7% required surgery or radiotherapy and 1% required hormones for metastases. There were no cancer related deaths.
In summary the study shows that in suitable patients, HIFU is a safe, low risk treatment which is repeatable and keeps the door open for further therapy if its needed.
What is focal cryoablation?
Focal cryoablation uses fine cryotherapy needles which allow the passage of compressed gasses to generate cold (argon) or heat (helium). The temperatures within the ice ball get down to at least -40 degrees C and the repeated freeze-thaw cycle kills cancer cells in the frozen areas. This technique is particularly good for anterior prostate cancers or in prostates where HIFU is unsuitable e.g. large glands or those with excessive calcifications. It can be used as a primary therapy or in men previously treated with radiotherapy. Focal cryoablation causes fewer side effects than whole gland therapy.
Focal cryoablation results
Results from focal cryotherapy have been assessed in a systematic review of published studies. In total 9 studies of primary focal cryotherapy were identified and these showed that between 71 and 93% of patients were free of cancer based upon their PSA at follow-ups ranging from 9 to 70 months. This suggests equivalent success rates to whole gland treatments in the short to medium term. The results from the primary focal cryotherapy studies also show relatively low rates of side-effects. Incontinence ranged from 0 to 3.6%, while ED occurred in 0–42%. Other side-effects such as haematuria, strictures and rectal fistulae were very uncommon.
Focal cryotherapy of localized prostate cancer: A systematic review of the literature. Available from: https://www.researchgate.net/publication/267815333_Focal_cryotherapy_of_localized_prostate_cancer_A_systematic_review_of_the_literature [accessed Nov 8, 2016].
841: Medium term outcomes following focal HIFU for the treatment of non-metastatic prostate cancer: A UK registry analysis of 625 cases Guillaumier S.1, Hamid S.1, Charman S.1, Van Der Meulen J.1, McCartan N.1, Shah K.1, Hindley R.2, Nigam R.3, Dudderidge T.4, Afzal N.5, Cornaby A.5, Lewi H.6, Persad R.7, Moore C.1, Virdi J.8, Arya M.8, Emberton M.1, Ahmed H.U.1