2 The procedure
2.1.2 Treatment options for patients with localised prostate cancer include active surveillance, radical prostatectomy, external beam radiotherapy, brachytherapy, and ablation of the whole gland using cryotherapy or HIFU. All radical treatment options are associated with substantial risks of sexual, urinary or bowel dysfunction. Focal therapy using HIFU is intended to be used in patients with localised prostate cancer – specifically patients with tumours that are confined to 1 prostatic lobe.
2.2.1 Imaging and biopsy mapping studies are used to confirm that the tumour is suitable for focal therapy and to show its precise location. With the patient under local or general anaesthesia, the bladder is catheterised and the HIFU probe is inserted transrectally. Real-time ultrasound imaging guidance and/or magnetic resonance guidance is used to position the probe and to monitor the procedure. Pulses of HIFU are directed at the targeted part of the prostate, inducing tumour necrosis by a thermal effect and causing cavitation (which can be visualised by ultrasound to assess the adequacy of treatment) until satisfactory ablation of the target area is judged to have occurred.
2.2.2 After treatment patients are usually followed up regularly with prostate-specific antigen (PSA) measurements, imaging, and repeated biopsies to detect recurrence.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
2.3.1 A case series of 12 patients reported overall and cancer-specific survival of 83% (10/12) and 100% respectively at median 10.6-year follow-up. Recurrence-free survival was 90% at 5 years and 38% at 10 years (absolute numbers not reported).
2.3.2 In the case series of 12 patients, treatment failure (defined as any positive biopsy and/or need for salvage therapy prompted by rising PSA levels) was observed in 42% (5/12) of all patients. In 1 patient prostate cancer was managed by further focal HIFU treatment and in 4 patients by androgen deprivation. All 5 patients were alive at 9.5–11-year follow-up.
2.3.3 In a case series of 20 patients, 10% (2/20) of patients had magnetic resonance imaging (MRI) findings suggestive of low volume recurrence of disease. One patient opted for active surveillance and the other was re-treated with focal HIFU. In case series of 12, 29 and 20 patients, there was no histological evidence of cancer in 92% (11/12), 77% (13/17) and 90% (17/19) of patients respectively at 12-month follow-up.
2.3.4 In the case series of 29 patients, median PSA levels decreased from 5.36 ng/ml before treatment to 3.42 ng/ml and 1.52 ng/ml after 2 and 3 years respectively. In the case series of 20 patients, mean PSA level decreased by 80% after treatment.
2.3.5 The Specialist Advisers listed key efficacy outcomes for this procedure as biochemical disease-free survival, absence of viable cancer on repeat biopsy, and MRI evidence of cancer ablation.
2.4.1 The case series of 20 patients reported a decrease in erectile dysfunction score (using the International Index of Erectile Dysfunction scoring system on a scale of 0–30; lower value indicates worse function) from a mean of 20.9 points at baseline to 14.3 points at 1 month (p = 0.004). However, scores at 3, 6, 9 and 12 months were not significantly different from baseline (mean scores of 17.9 [p = 0.278], 21.7 [p = 0.705], 23.3 [p = 0.198] and 21.8 [p = 0.619] respectively). Ninety-five per cent (19/20) of patients had erectile function sufficient for penetrative sex at 12-month follow-up.
2.4.2 In the case series of 12 patients, 1 patient developed epididymo-orchitis and another had an asymptomatic urinary tract infection.
2.4.3 The Specialist Advisers listed adverse events reported in the literature as bladder neck stenosis, acute retention and erectile dysfunction in those who are preoperatively potent.
2.5.1 The Committee was mindful of the variable natural history of prostate cancer; this underpinned the recommendation for controlled studies and the need for details of long-term outcomes.
2.5.2 The Committee noted the potential for this procedure to avoid many of the complications of more radical treatments for localised prostate cancer in properly selected patients, if further evidence supports its efficacy.
2.5.3 The Committee noted a number of patient commentaries that described benefits from the procedure, but which reported instances of sexual dysfunction.