Focused ultrasound and prostate cancer

Abstract

Focused ultrasound (FUS) has been utilized for the treatment of localized prostate cancer. Initially, FUS was performed as a whole-gland treatment comparable to radical prostatectomy or radiation therapy. However, after overall downward stage migration due to health screening programs involving prostate-specific antigen testing, as well as advances in conservative or observative strategies such as active surveillance, FUS has evolved from a whole-gland treatment to a focal treatment. This new treatment technique aims to ablate tumors while preserving the normal prostate tissue, thereby ensuring better preservation of urinary and erectile function. In this article, we review the mechanism and clinical outcomes of the FUS procedure.

Keywords: Focused ultrasound; High intensity focused ultrasound; Prostatic neoplasms.

Fig. 1.. Some possibility of empty spots and missing lesions always exists during ablation.

A. The yellow circles indicate the well-aligned theoretical focal points in the preoperative ablation plan. B. Errors and missing lesions between the ablated points are possible due to prostate movement and/or swelling. The red circle indicates a theoretical missing spot during ablation.

Fig. 2.. Magnetic resonance images from a 73-year-old man with prostate cancer who was treated with left hemi-ablation using focused ultrasound with transurethral prostatectomy.

A, C. The prostate size was estimated as 44 cc based on a preoperative T2-weighted image (A, axial image on the mid-prostate; C, sagittal image at the midline). B, D. At 6 months after focused ultrasound ablation (left hemi-ablation), the size of the remaining prostate was estimated as 6-7 mL with negative prostate biopsies in both lobes (B, axial image; D, sagittal image).