Focal HIFU therapy for anterior compared to posterior prostate cancer lesions.

OBJECTIVE: To compare cancer control in anterior compared to posterior prostate cancer lesions treated with a focal HIFU therapy approach. MATERIALS AND METHODS: In a prospectively maintained national database, 598 patients underwent focal HIFU (Sonablate®500) (March/2007-November/2016). Follow-up occurred with 3-monthly clinic visits and PSA testing in the first year with PSA, every 6-12 months with mpMRI with biopsy for MRI-suspicion of recurrence. Treatment failure was any secondary treatment (ADT/chemotherapy, cryotherapy, EBRT, RRP, or re-HIFU), tumour recurrence with Gleason ≥ 3 + 4 on prostate biopsy without further treatment or metastases/prostate cancer-related mortality. Cases with anterior cancer were compared to those with posterior disease. RESULTS: 267 patients were analysed following eligibility criteria. 45 had an anterior focal-HIFU and 222 had a posterior focal-HIFU. Median age was 64 years and 66 years, respectively, with similar PSA level of 7.5 ng/ml and 6.92 ng/ml. 84% and 82%, respectively, had Gleason 3 + 4, 16% in both groups had Gleason 4 + 3, 0% and 2% had Gleason 4 + 4. Prostate volume was similar (33 ml vs. 36 ml, p = 0.315); median number of positive cores in biopsies was different in anterior and posterior tumours (7 vs. 5, p = 0.009), while medium cancer core length, and maximal cancer percentage of core were comparable. 17/45 (37.8%) anterior focal-HIFU patients compared to 45/222 (20.3%) posterior focal-HIFU patients required further treatment (p = 0.019). CONCLUSION: Treating anterior prostate cancer lesions with focal HIFU may be less effective compared to posterior tumours.

Prostate Specific Antigen Criteria to Diagnose Failure of Cancer Control following Focal Therapy of Nonmetastatic Prostate Cancer Using High Intensity Focused Ultrasound.

PURPOSE: We determined whether prostate specific antigen criteria after focal high intensity focused ultrasound to treat prostate cancer could diagnose treatment failure. MATERIALS AND METHODS: A total of 598 patients in a prospectively maintained national database underwent focal high intensity focused ultrasound with a Sonablate® 500 device from March 2007 to November 2016. Followup consisted of 3-month clinic visits and prostate specific antigen testing in year 1 with prostate specific antigen measurement every 6 to 12 months and multiparametric magnetic resonance imaging with biopsy for magnetic resonance imaging suspicious for recurrence. Treatment failure was considered any secondary treatment, tumor recurrence with Gleason 3 + 4 or greater disease on prostate biopsy without further treatment or metastasis and/or prostate cancer related mortality. To diagnose failure we evaluated a series of nadir + x thresholds with x values of 0.1 to 2.0 ng/ml. RESULTS: Median patient age was 65 years (IQR 60-71) and the median Gleason score was 7 (range 6-9). Gleason 3 + 4 or greater disease was present in 80% of cases. Tumors were radiologically staged as T1c-T2c in 522 of the 596 patients (88%) and as T3a/b in 74 (12.4%). Baseline median prostate specific antigen was 7.80 ng/ml (IQR 5.96-10.45) in failed cases and 6.77 ng/ml (IQR 2.65-9.71) in cases without failure. Optimal performance according to the Youden index to indicate the most appropriate nadir + x at all analyzed time points at 3-month intervals showed that nadir + 1.0 ng/ml would have 27.3% to 100% sensitivity and 39.4% to 85.6% specificity depending on the time of evaluation in the first 3 years. Nadir + 1.5 ng/ml showed 18.2% to 100% sensitivity and 60.6% to 91.8% specificity with nadir + 2.0 ng/ml leading to similar sensitivity and specificity ranges. Nadir + 1.0 ng/ml at 12 months and nadir + 1.5 ng/ml at 24 and 36 months had 100% sensitivity and 96.1% to 100% negative predictive value. CONCLUSIONS: Following focal high intensity focused ultrasound a prostate specific antigen nadir of 1.0 ng/ml at 12 months and 1.5 ng/ml at 24 to 36 months might be used to triage men requiring magnetic resonance imaging and biopsy. These data need prospective validation.

An Exploratory Study of Dose Escalation vs Standard Focal High-Intensity Focused Ultrasound for Treating Nonmetastatic Prostate Cancer.

Objective: Analysis of treatment success regarding oncological recurrence rate between standard and dose escalation focal high-intensity focused ultrasound (HIFU) of prostate cancer. Materials and Methods: In this analysis of our prospectively maintained HIFU (Sonablate® 500) database, 598 patients were identified who underwent a focal HIFU (Sonablate 500) between March 2007 and November 2016. Follow-up occurred with 3-monthly clinic visits and prostate specific antigen (PSA) testing in the first year. Thereafter, PSA was measured 6-monthly or annually at least. Routine and for-cause multiparametric MRI (mpMRI) was conducted with biopsy for MRI suspicion of recurrence. Treatments were delivered in a quadrant or hemiablation fashion depending on the gland volume as well as tumor volume and location. Before mid-2015, standard focal HIFU was used (two HIFU blocks); after this date, some urologists conducted dose escalation focal HIFU (three overlapping HIFU blocks). Propensity matching was used to ensure two matched groups, leading to 162 cases for this analysis. Treatment failure was defined by any secondary treatment (systemic therapy, cryotherapy, radiotherapy, prostatectomy, or further HIFU), metastasis from prostate cancer without further treatment, tumor recurrence with Gleason score ≥7 (≥3 + 4) on prostate biopsy without further treatment, or prostate cancer-related mortality. Complications and side-effects were also compared. Results: Median age was 64.5 years (interquartile range [IQR] 60-73.5) in the standard focal-HIFU group and 64.5 years (IQR 60-69) in the dose-escalation group. Median prostate volume was 37 mL (IQR 17-103) in the standard group and 47.5 mL (IQR 19-121) in the dose-escalation group. As tumor volume on mpMRI and Gleason score were major matching criteria, these were identical with 0.43 mL (IQR 0.05-2.5) and Gleason 3 + 3 = 6 in 1 out of 32 (3%), 3 + 4 = 7 in 27 out of 32 (84%), and 4 + 3 = 7 in 4 out of 32 (13%). Recurrence in treated areas was found in 10 out of 32 (31%) when standard treatment zones were applied, and in 6 out of 32 (19%) of dose-escalation focal HIFU (p = 0.007). Conclusion: This exploratory study shows that dose escalation focal HIFU may achieve higher rates of disease control compared with standard focal HIFU. Further prospective comparative studies are needed.