A Whole of Population, Multiuser Series of High-Intensity Focused Ultrasound for Management of Localized Prostate Cancer: Outcomes and Implications

Clinical application of the therapeutic ultrasound in urologic disease: Part II of the therapeutic ultrasound in urology

This article aimed to review the clinical application and evidence of the therapeutic ultrasound in detail for urological diseases such as prostate cancer, kidney tumor, erectile dysfunction, and urolithiasis. We searched for articles about high-intensity focused ultrasound (HIFU), extracorporeal shock wave therapy, ultrasound lithotripsy, and extracorporeal shockwave lithotripsy (ESWL) in the MEDLINE and Embase. HIFU may be indicated as a primary treatment for low- or intermediate-risk prostate cancer, and salvage therapy for local recurrence as a promising way to address the limitations of current standard therapies. The application of HIFU in treating kidney tumors has scarcely been reported with unsatisfactory results. Evidence indicates that low-intensity shockwave therapy improves subjective and objective erectile function in patients with erectile dysfunction. Regarding the application of ultrasound in stone management, the novel combination of ultrasound lithotripsy and other energy sources in a single probe promises to be a game-changer in efficiently disintegrating large kidney stones in percutaneous nephrolithotomy. ESWL is losing its role in managing upper urinary tract calculi worldwide. The burst-wave lithotripsy and ultrasound propulsion could be the new hope to regain its position in the lithotripsy field. According to our investigations and reviews, cavitation bubbles of the therapeutic ultrasound are actively being used in the field of urology. Although clinical evidence has been accumulated in urological diseases such as prostate cancer, kidney tumor, erectile dysfunction, and lithotripsy, further development is needed to be a game-changer in treating these diseases.

The primary treatment of prostate cancer with high-intensity focused ultrasound: A systematic review and meta-analysis

BACKGROUND

We systematically evaluated the evidences on oncological and functional outcomes of high-intensity focused ultrasound (HIFU) as the primary treatment for localized prostate cancer (PCa).

METHODS

A systematic review was used Medline, Embase, and the Cochrane Library from the inception of each database. The review analyzed the oncological and functional outcomes of HIFU in the treatment of PCa. The RevMan 5.3 software was used for quantity analysis incidence of complications.

RESULTS

Twenty-seven articles were included for analysis with a total of 7393 patients. Eighteen studies investigated the whole-gland HIFU, and the duration of follow-up ranged from 2 to 168 months. After whole-gland HIFU, the mean prostate-specific antigen (PSA) nadir was found to be 0.4 to 1.95 ng/mL and the mean time to PSA nadir was 2.4 to 5.4 months. The rate of positive biopsy after HIFU was 4.5% to 91.1%. Meta-analysis revealed the incidences of urinary incontinence, impotence, urinary obstruction, retention, and infection was 10%, 44%, 15%, 11%, 7%, respectively. Nine studies investigated partial-gland HIFU, and the duration of follow-up was 1 to 131 months. After partial-gland HIFU, the mean PSA nadir was 1.9 to 2.7 ng/mL and the mean time to PSA nadir 5.7 to 7.3 months. The rate of positive biopsy after HIFU in the treatment area was 14% to 37.5%. Meta-analysis revealed the incidences of urinary incontinence, impotence, urinary obstruction, retention, and infection was 2%, 21%, 2%, 9%, 11%, respectively.

CONCLUSIONS

Early evidence suggested the partial-gland HIFU was safer than whole-gland HIFU, and they had similar oncological outcomes. More prospective randomized controlled trials of whole-gland and partial-gland HIFU for PCa was needed.

Survival and quality of life outcomes of high-intensity focused ultrasound treatment of localized prostate cancer

BACKGROUND

To evaluate the survival and quality of life (QoL) outcomes of high-intensity focused ultrasound (HIFU) whole-gland ablation for localized prostate cancer.

METHODS

Over 8 years, men with localized prostate cancer treated with whole-gland HIFU were prospectively followed. Transrectal prostate ablation was performed under general anesthesia with Sonablate-500® (Sonacare Medical©, Charlotte, North Carolina, USA). The primary outcome was failure-free survival defined as no transition to any of the following: (1) local salvage therapy (surgery or radiotherapy), (2) systemic therapy, (3) metastases, or (4) prostate cancer-specific mortality. Secondary outcomes included both survival outcomes and QoL measures.

RESULTS

Of 70 men, 29.7% had International Society of Urological Pathology (ISUP) grade 1, 43.8% ISUP 2, 10.9% ISUP 3, and 15.6% ISUP 4 disease. At median follow-up of 83.4 months, overall mortality was 8.6% and prostate cancer-specific mortality 0%. Failure-free survival was 78.2% at 5 years and 71.2% at 7 years. Of all men, 7.1% of men developed metastases, with median metastasis-free survival of 75.4 months. There was negligible post-HIFU urinary incontinence or lower urinary tract symptom with a median Male Urogenital Distress Inventory score of 32 at 6 months and 33 at 12 months and median IPSS of 4 at 6 months and 3 at 12 months. Median Radiation Therapy Oncology Group rectal toxicity score was 0 throughout. In men who had mild or no erectile dysfunction at baseline (International Index of Erectile Function ≥17), the mean International Index of Erectile Function score declined to 37% from 23.5 at baseline to 14.7 at 12 months.

CONCLUSION

At median follow-up of 7 years, whole-gland HIFU appears to have comparable survival outcomes with other cohort studies involving radical prostatectomy and radiotherapy patient. It has low impact on QoL, preserved urinary continence, and erectile function approximate to nerve-sparing prostatectomy. Whole-gland HIFU presents a potential alternative minimally invasive and safe option for the treatment of localized prostate cancer.

Medium-term Outcomes after Whole-gland High-intensity Focused Ultrasound for the Treatment of Nonmetastatic Prostate Cancer from a Multicentre Registry Cohort

BACKGROUND

High-intensity focused ultrasound (HIFU) is a minimally-invasive treatment for nonmetastatic prostate cancer.

OBJECTIVE

To report medium-term outcomes in men receiving primary whole-gland HIFU from a national multi-centre registry cohort.

DESIGN, SETTING, AND PARTICIPANTS

Five-hundred and sixty-nine patients at eight hospitals were entered into an academic registry.

INTERVENTION

Whole-gland HIFU (Sonablate 500) for primary nonmetastatic prostate cancer. Redo-HIFU was permitted as part of the intervention.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Our primary failure-free survival outcome incorporated no transition to any of the following: (1) local salvage therapy (surgery or radiotherapy), (2) systemic therapy, (3) metastases, or (4) prostate cancer-specific mortality. Secondary outcomes included adverse events and genitourinary function.

RESULTS AND LIMITATIONS

Mean age was 65 yr (47-87 yr). Median prostate-specific antigen was 7.0 ng/ml (interquartile range 4.4-10.2). National Comprehensive Cancer Network low-, intermediate-, and high-risk disease was 161 (28%), 321 (56%), and 81 (14%), respectively. One hundred and sixty three of 569 (29%) required a total of 185 redo-HIFU procedures. Median follow-up was 46 (interquartile range 23-61) mo. Failure-free survival at 5 yr after first HIFU was 70% (95% confidence interval [CI]: 64-74). This was 87% (95% CI: 78-93), 63% (95% CI: 56-70), and 58% (95% CI: 32-77) for National Comprehensive Cancer Network low-, intermediate-, and high-risk groups, respectively. Fifty eight of 754 (7.7%) had one urinary tract infection, 22/574 (2.9%) a recurrent urinary tract infection, 22/754 (3%) epididymo-orchitis, 227/754 (30%) endoscopic interventions, 1/754 (0.13%) recto-urethral fistula, and 1/754 (0.13%) osteitis pubis. Of 206 known to be pad-free pre-HIFU, 183/206 (88%) remained pad free, and of 236 with good baseline erectile function, 91/236 (39%) maintained good function. The main limitation is lack of long-term data.

CONCLUSIONS

Whole-gland HIFU is a repeatable day-case treatment that confers low rates of urinary incontinence. Disease control at a median of just under 5 yr of follow-up demonstrates its potential as a treatment for nonmetastatic prostate cancer. Endoscopic interventions and erectile dysfunction rates are similar to other whole-gland treatments.

PATIENT SUMMARY

In this report we looked at the 5-yr outcomes following whole-gland high-intensity focused ultrasound treatment for prostate cancer and found that cancer control was acceptable with a low risk of urine leakage. However, risk of erectile dysfunction and further operations was similar to other whole-gland treatments like surgery and radiotherapy.