Dynamic Contrast-Enhanced MR Imaging in Detecting Local Tumor Progression after HIFU Ablation of Localized Prostate Cancer

Radical prostatectomy remains the standard treatment for patients with localized prostate cancer and a life expectancy exceeding 10 years (1). For patients with a life expectancy of less than 10 years who are not fit for surgery or do not want to experience the potential side effects of surgery, several alternative treatments have been introduced, such as, three-dimensional radiotherapy, brachytherapy, cryotherapy, and high intensity focused ultrasound (HIFU) (2-4). HIFU can result in coagulation necrosis in targeted tissue by the conversion of mechanical energy into heat and a cavitation effect (5). Currently, HIFU is a valuable alternative for welland moderately differentiated localized prostate cancer as well as for local recurrence after external beam radiation therapy (68). After HIFU for clinically localized prostate cancer, the accurate assessment of residual or recurrent cancer is much important to determine the planning of treatment strategies as second-line treatment. INTRODUCTION