MR Imaging/Ultrasound Fusion–Guided Biopsy and Primary Focal Therapy for Localized Prostate Cancer

Advances in imaging diagnostics, particularly MRI, have enabled the visualization of clinically significant prostate cancer. Furthermore, advances in image-fusion technology have made it possible to accurately target these visualized lesions and obtain tissue samples through precise needle placement. These developments now enable systematic intraprostatic localization of clinically significant prostate cancer. Traditionally, standard treatment options for localized prostate cancer have involved whole-gland therapies, such as radical prostatectomy and radiation therapy. Although these approaches provide excellent oncological control and favorable long-term outcomes, they are associated with treatment-related adverse events, including urinary incontinence and sexual dysfunction, which can substantially impair quality of life. Focal therapy has emerged as a treatment strategy designed to address these limitations by selectively targeting only the clinically significant cancer within the prostate, thereby aiming to achieve a balance between oncological control and functional preservation. This approach has become technically feasible due to the MRI visibility of clinically significant cancer and precise image-guidance techniques, as well as the development of various ablation technologies. In this review, we provide an overview of MRI/ultrasound fusion–guided biopsy and discuss the current status and clinical implications of focal therapy for localized prostate cancer enabled by this imaging-guided approach.