Initial experience of transurethral ultrasound ablation of the prostate in Asia

Transurethral ultrasound ablation of the prostate (TULSA) is a novel modality for the treatment of localised prostate cancer. linear and the treatment is precisely controlled by closed-loop control of ultrasound emission the of a in a real-time The surface of the urethra and the rectal wall are cooled during the treatment. – The pivotal trial in Europe and North America showed significantly low rates of urinary incontinence and erectile dysfunction without compromising cancer control for low and intermediate-risk cancer. We herein show our initial experience of TULSA for the first time in Asia.

Transurethral ultrasound ablation of the prostate (TULSA) is a novel modality for the treatment of localised prostate cancer. 1-4 TULSA uses linear high-frequency ultrasound to heat the prostatic tissue, and the treatment margin is precisely controlled by closed-loop control of ultrasound emission by measuring the temperature of prostatic tissue inside a magnetic resonance imaging (MRI) bore in a real-time manner.
The surface of the urethra and the rectal wall are cooled during the treatment. [1][2][3][4] The pivotal trial in Europe and North America showed significantly low rates of urinary incontinence and erectile dysfunction without compromising cancer control for low and intermediate-risk cancer. 4 We herein show our initial experience of TULSA for the first time in Asia.
Five men with localised prostate cancer who underwent TULSA and followed for over 1 year are included. There were 4 cases of highrisk cancer and one case of intermediate-risk cancer. Two men underwent whole-gland ablation and three partial ablation. Patients' characteristics and representative MRI images are shown in Table S1 and We herein showed our initial experience of TULSA in Japanese patients. Cancer control up to 1Y was satisfying in 4 patients. One of the important features of TULSA is that it has a very low rate of urinary incontinence, which has been the most significant unsolved problem after radical prostatectomy. 7 Very accurate control of the treatment boundary brings secure ablation of the tissue to the boundary with no damages beyond, as all the patients in our series were continent after TULSA. One patient requested the preservation of erectile and ejaculatory functions, both of which were successfully preserved by unilateral partial ablation while excluding the ejaculatory ducts. Accurate margin control offers a great advantage for patients who seek for retaining their function. TULSA is an incision-free therapy, which can be performed on a single day with a short-term hospitalisation. No decline in QOL was observed, and patients' satisfaction score was considerably high. The prostate swells after heat ablation and the prostatic urethra can be obstructed especially after a whole-gland treatment. In other TULSA trials, a suprapubic catheter was placed during treatment. 1,4 However, we applied self-CIC temporarily for the patients who developed voiding difficulty because we consider CIC is less invasive for the post-treatment management of urination. Our early experience shows that TULSA is safely applicable for treating localised prostate cancer, with a minimal impact on patients' QOL.

ACKNOWLEDGEMENT
There is no financial support related to this study.
F I G U R E 1 (A) Changes in prostate-specific antigen (PSA) levels. The thin broken line represents the case with PSA relapse. The thick broken line represents the case of partial ablation. The thick solid line also represents the case of partial ablation who underwent androgen deprivation therapy before transurethral ultrasound ablation of the prostate (TULSA). (B-F) Expanded Prostate Cancer Index Composite average scores. Note that urinary score dropped at 1 M due to voiding difficulty but recovered thereafter. There was no significant change in hormone or bowel scores. Four patients were sexually inactive before TULSA, and average scores are low. Satisfaction score was kept high throughout the period. The bars denotes standard error.