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.
Keywords: Biochemical failure; Focal therapy; High intensity focused ultrasound; Prostate cancer.