Introduction: Focal therapy aims to selectively ablate tumor lesions and preserve prostate tissue, thus minimizing side effect whilst providing oncological control. The experience of the first 2 years lead to improved diagnostic work up prior to HIFU with better patient selection and less tumor recurrence in the following 5 years. The strong recommendation of control biopsy in the follow up, lead to a reliable and early selection of patients requiring salvage therapy and thus improving oncological results. Methods: This is a prospective evaluation of 164 patients undergoing focal high intensity focused ultrasound (HIFU) in our institution from July 2015 till June 2022. Patients were required to have a unilateral Gleason score (GS) =7, stage T1 or T2 and a PSA level of =15 ng/ml. Tumor localization was done using multiparametric MRI followed by mainly transrectal targeted and systematic biopsies of any lesion PI-RADS =3. Systematic biopsy was recommended 1 year after HIFU with PSA levels every 3 months. An MRI was scheduled at 3 years post HIFU. In the control biopsy significant cancer recurrence was defined as >3mm GS 3+3, >3 positive cores or any GS =3+4; these patients were offered further treatment; either a repeat HIFU, radical prostatectomy (RP) or radiation therapy (RT). Urinary and erectile function were assessed using validated questionnaires. Results: Median PSA prior to HIFU was 6 ng/ml, the median follow-up was 61 months. 38% of the patients had low, 60% intermediate and 2% high risk disease. Median PSA level 2 years post HIFU was 1.9 ng/ml. Of the 119 control biopsies 50% had no evidence of tumor, 36% had insignificant tumor evidence and 14 % showed evidence of significant prostate cancer according to the above defined criteria. Significant infield recurrence occurred in 6 patients (4%) and significant outfield recurrence was seen in 10 patients (6%). 5 patients received a repeat HIFU, 4 patients a RT and 7 had a RP. There were no cases of distant metastasis, no need for palliative antiandrogen therapy (ADT) and no major complications. Urinary continence and erectile function were preserved in 99.5% and 85% respectively. Conclusions: At 7 years, HIFU therapy showed efficient oncological control rates with a radical treatment free survival rate of 93%. Significant infield recurrence was seen in 4% and significant outfield recurrence in 6% of patients. There was no distant metastasis and no need for palliative ADT. HIFU is associated with excellent preservation of continence and erectile function with very low morbidity. SOURCE OF Funding: Non funded.
