Urethra-sparing high-intensity focused ultrasound for localized prostate cancer: Functional and oncological outcomes

Oncological and Functional Outcomes of Whole-Gland HIFU as the Primary Treatment for Localized Prostate Cancer: A Systematic Review

INTRODUCTION

High-intensity focused ultrasound (HIFU) is regarded as a promising alternative treatment option for localized prostate cancer (PCa) as it has been proposed to offer similar oncologic control to the standard of care, but with significantly reduced treatment-related side effects. This systematic literature review assesses the available evidence of whole-gland HIFU as primary treatment for localized PCa.

METHODS

MEDLINE (PubMed) was searched for studies investigating oncological and functional outcomes following whole-gland HIFU as primary treatment for localized PCa. Our primary outcomes for the review were biochemical disease-free survival rates (BDFS), overall and PCa-specific survival rates as well as negative biopsy rates. Our secondary outcomes were functional results and complications of the treatment.

RESULTS

A total of 375 articles were identified, of which 35 were included in the present review. All 35 articles were prospective or retrospective case series. Mean/median duration of follow-up across studies was 10.9 to 94 months, and 6618 patients were included in the review. The BDFS rate varied greatly across studies from 21.7% to 89.2% during follow-up. The 10-year PCa-specific survival rate following HIFU was 90%, 99%, and 100% in 3 studies. Negative biopsy rates post-HIFU ranged from 20% to 92.7% across studies. Common side effects to HIFU included urinary incontinence (grade 1: 0%-22.7%), erectile dysfunction (11.6%-77.1%), urinary tract infections (1.5%-47.9%), and bladder outlet obstruction mainly as urethral strictures (7%-41.2%).

CONCLUSION

Great variation in oncological and functional outcomes was seen across studies. More prospective trials are needed before whole-gland HIFU can be considered as a treatment option for localized PCa.

High-intensity focused ultrasound with visually directed power adjustment for focal treatment of localized prostate cancer: systematic review and meta-analysis

PURPOSE

To characterize patient outcomes following visually directed high-intensity focused ultrasound (HIFU) for focal treatment of localized prostate cancer.

METHODS

We performed a systematic review of cancer-control outcomes and complication rates among men with localized prostate cancer treated with visually directed focal HIFU. Study outcomes were calculated using a random-effects meta-analysis model.

RESULTS

A total of 8 observational studies with 1,819 patients (median age 67 years; prostate-specific antigen 7.1 mg/ml; prostate volume 36 ml) followed over a median of 24 months were included. The mean prostate-specific antigen nadir following visually directed focal HIFU was 2.2 ng/ml (95% CI 0.9-3.5 ng/ml), achieved after a median of 6 months post-treatment. A clinically significant positive biopsy was identified in 19.8% (95% CI 12.4-28.3%) of cases. Salvage treatment rates were 16.2% (95% CI 9.7-23.8%) for focal- or whole-gland treatment, and 8.6% (95% CI 6.1-11.5%) for whole-gland treatment. Complication rates were 16.7% (95% CI 9.9-24.6%) for de novo erectile dysfunction, 6.2% (95% CI 0.0-19.0%) for urinary retention, 3.0% (95% CI 2.1-3.9%) for urinary tract infection, 1.9% (95% CI 0.1-5.3%) for urinary incontinence, and 0.1% (95% CI 0.0-1.4%) for bowel injury.

CONCLUSION

Limited evidence from eight observational studies demonstrated that visually directed HIFU for focal treatment of localized prostate cancer was associated with a relatively low risk of complications and acceptable cancer control over medium-term follow-up. Comparative, long-term safety and effectiveness results with visually directed focal HIFU are lacking.

Urethra-sparing surgery for a prostate cancer lesion in the anterior urethral zone with magnetic resonance-guided focused ultrasound: a case report

Prostate cancer (PCa) is the most common malignancy among men worldwide. High-intensity focused ultrasound (HIFU) is a focal therapeutic strategy for low- to intermediate-risk PCa with a low risk of complications. However, lesions located in the anterior urethral zone are challenging to treat with this approach because it is difficult to avoid urethral injury during HIFU therapy, which might further cause urethral stricture and symptoms related to bladder outlet obstruction (BOO). Here, we present the case of a 79-year-old male with elevated prostate-specific antigen (PSA) levels for over 1 year. Multiparametric magnetic resonance imaging revealed a 1.8 cm × 1.0 cm mass covering an area of the anterior urethral zone. Histopathological examination revealed an International Society of Urological Pathology grade group 3 acinar adenocarcinoma. Given the patient’s request for functional preservation, a magnetic resonance-guided focused ultrasound surgery was performed. During the operation, a urethra-sparing approach was utilized by administering proper energy and adjusting the sequence of the sonications. The patient developed urinary retention after catheter removal less than 48 h after the treatment, which resolved after removal of the second catheter a week later. On a follow-up visit 3 months after the treatment, evaluation by the level of PSA and multiparametric magnetic resonance imaging showed no recurrence of PCa. No significant changes in the International Prostate Symptom Score and Quality of Life score were found compared to baseline scores. With proper adjustment, magnetic resonance-guided focused ultrasound surgery could be safely used for urethra-sparing surgeries for PCa lesions in the anterior urethral zone, without influencing post-treatment urination. The indwelling time of the catheter should be extended appropriately for full recovery from treatment-related prostatic edema around the prostatic urethra to avoid urinary retention.

Development and future prospective of treatment for localized prostate cancer with high-intensity focused ultrasound

High-intensity focused ultrasound (HIFU) was experimentally used for focal therapy for anti-cancer effects in prostate cancer (PC). Focal therapy is a diagnosis-based investigational treatment option for localized PC that cures clinically significant PC (csPC) while preserving the anatomical structures related to urinary and sexual function based on its spread observed using multi-parametric magnetic resonance imaging (mpMRI). The European Association of Urology indicated that the current status of focal therapy for localized PC was an investigational modality and encouraged prospective recording of outcomes and recruitment of suitable patients in 2018. During the last few years, large-population multi- and single-center prospective studies have investigated focal therapy as a treatment strategy for localized PC. In a multicenter prospective study with 5-year follow-up, failure-free survival, which was defined as avoidance of local salvage therapy (surgery or radiotherapy), systemic therapy, metastases, and prostate cancer-specific death, was 88%. In the previous studies, there was no significant influence on urinary function before and at 3 months after the treatment, although transient impairment was reported 1 month after the treatment. Pad- and leak-free continence was preserved in 80-100% of the patients after treatment. Erectile function was significantly impaired in the initial 3 months after treatment compared to the pretreatment values, but it improved 6 months after the focal therapy in the previous reports. Paired comparison studies and cohort studies with long-term follow-up will contribute to verifying this treatment's clinical outcomes for patients with localized PC.

Current Landscape of Sonodynamic Therapy for Treating Cancer

Simple Summary

Recently, ultrasound has advanced in its treatment opportunities. One example is sonodynamic therapy, a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. The combination of the ultrasound and chemical sonosensitizer amplifies the drug’s ability to target cancer cells. Combining multiple chemical sonosensitizers with ultrasound can create a synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. This review provides an oversight of the application of this treatment to various types of cancer, including prostate cancer, glioma, and pancreatic ductal adenocarcinoma tumors.

Abstract

Recent advancements have tangibly changed the cancer treatment landscape. However, curative therapy for this dreadful disease remains an unmet need. Sonodynamic therapy (SDT) is a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. A high-intensity focused ultrasound (HIFU) beam is used to destroy or denature targeted cancer tissues. Some SDTs are based on unfocused ultrasound (US). In some SDTs, HIFU is combined with a drug, known as a chemical sonosensitizer, to amplify the drug’s ability to damage cancer cells preferentially. The mechanism by which US interferes with cancer cell function is further amplified by applying acoustic sensitizers. Combining multiple chemical sonosensitizers with US creates a substantial synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. Therefore, the minimally invasive SDT treatment is currently attracting attention. It can be combined with targeted therapy (double-targeting cancer therapy) and immunotherapy in the future and is expected to be a boon for treating previously incurable cancers. In this paper, we will consider the current state of this therapy and discuss parts of our research.

Future perspective of focal therapy for localized prostate cancer

Objective

To summarize the recent literature discussing focal therapy for localized prostate cancer.

Methods

A thorough literature review was performed using PubMed to identify recent studies involving focal therapy for the treatment of localized prostate cancer.

Results

In an effort to decrease the morbidity associated with prostate cancer treatment, many urologists are turning to focal therapy as an alternative treatment option. With this approach, the cancer bearing portion of the prostate is targeted while leaving the benign tissue untouched. Multiparametric magnetic resonance imaging remains the gold standard for visualization during focal therapy, but new imaging modalities such as prostate specific membrane antigen/positron emission tomography and contrast enhanced ultrasound are being investigated. Furthermore, several biomarkers, such as prostate cancer antigen 3 and prostate health index, are used in conjunction with imaging to improve risk stratification prior to focal therapy. Lastly, there are several novel technologies such as nanoparticles and transurethral devices that are under investigation for use in focal therapy.

Conclusion

Focal therapy is proving to be a promising option for the treatment of localized prostate cancer. However, further study is needed to determine the true efficacy of these exciting new technologies.

Significant Impact of the Anterior Transition Zone Portion Treatment on Urinary Function After Focal Therapy with High-Intensity Focused Ultrasound for Prostate Cancer

Background: There is lack of evaluation of the effect of the treated area on the urinary function after focal therapy. The objectives of the study is to evaluate the effects of focal therapy on urinary function in the anterior portion of the transition zone (TZ) with transrectal high-intensity focused ultrasound (HIFU) for localized prostate cancer (PCa). Methods: From 2016 to 2018, patients who were diagnosed as having localized PCa and treated with focal therapy with HIFU, were included prospectively. The urinary function and complications were evaluated separately in the treated regions of the anterior TZ (TZ group) and other portions (other group) for 12 months. Before and after the treatment, the International Prostate Symptom Score (IPSS), IPSS Quality Of Life (QOL), Overactive Bladder Symptom Score (OABSS), and uroflowmetry were evaluated to assess the urinary function. Results: Ninety patients were included in the study. There was no significant differences in the patients' characteristics between the two groups. At 1 month after the treatment, IPSS (p = 0.011), IPSS QOL (p = 0.002), OABSS (p = 0.002), maximum flow rates (p = 0.011), and residual urine volume (p = 0.011) in TZ group were significantly deteriorated compared with the other group. Multivariate logistic regression analysis revealed that anterior TZ treatment (odds ratio, 3.386; p = 0.029) was an independent risk factor for the deterioration with ≥32% of preoperative status of maximum flow rates. Concerning complication, the rates of Grade 2 urinary retention and Grade 3 urethral stricture were 15.4% and 11.5% in the TZ group and 0% and 0% in the other group, respectively. Conclusions: There was a greater risk of urinary dysfunction with treatment in the anterior TZ portion than in the other portion at 1 month after focal therapy with HIFU.

Magnetic resonance imaging of the prostate after focal therapy with high-intensity focused ultrasound

For clinically significant, locally confined prostate cancer, whole-gland radical prostatectomy and radiotherapy are established effective treatment strategies that, however, come at a cost of significant morbidity related to urinary and sexual side effects. The concept of risk stratification paired with a better understanding of prognostic factors has led to the development of alternative management options including active surveillance and focal therapy for appropriately selected patients with localized disease. High-intensity focused ultrasound (HIFU) is one such minimally invasive, image-guided treatment option for prostate cancer. Due to the relative novelty of HIFU and the increased use of magnetic resonance imaging in prostate cancer, many radiologists are not yet familiar with imaging findings related to HIFU, their temporal evolution as well as imaging appearance of recurrent disease after this type of focal therapy. HIFU induces sharply demarcated, localized coagulative necrosis of a tumor through thermal energy delivered via an endorectal or transurethral ultrasound transducer. In this pictorial review, we aim at providing relevant background information that will guide the reader through the general principles of HIFU in the prostate, as well as demonstrate the imaging appearance of expected post-HIFU changes versus recurrent tumor.

Apical periurethral transition zone lesions: MRI and histology findings

PURPOSE

Apical periurethral transition zone (TZ) cancers can pose unique problems for surgery and radiation therapy. Here, we describe the appearance of such cancers on multiparametric MRI (mpMRI) and correlate this with histopathology derived from MRI-targeted biopsy.

MATERIALS AND METHODS

Between May 2011 and January 2019, a total of 4381 consecutive patients underwent 3 T mpMRI. Of these, 53 patients with 58 apical periurethral TZ lesions underwent TRUS/MRI fusion-guided biopsy and 12-core systematic TRUS-guided biopsy. Correlation was made with patient age, PSA, PSA density, whole prostate volume, and Gleason scores.

RESULTS

A total 53 men (median age 68 years, median PSA 7.94 ng/ml) were identified as having at least one apical periurethral TZ lesion on mpMRI and 5 (9%) patients had more than one apical periurethral lesion. Thus, 58 lesions were identified in 53 patients. Of these 37/53 patients (69%) and 40/58 lesions were positive at biopsy for prostate cancer. Seven were diagnosed by 12-core systematic TRUS-guided biopsy and 34 were diagnosed by TRUS/MRI fusion-guided biopsy. Gleason score was ≥ 3 + 4 in 34/58 (58%) lesions.

CONCLUSION

Identification of apical periurethral TZ prostate cancers is important to help guide surgical and radiation therapy as these tumors are adjacent to critical structures. Because of the tendency to undersample the periurethral zone during TRUS biopsy, MRI-guided biopsy is particularly helpful for detecting apical periurethral TZ prostate cancers many of which prove to be clinically significant.

Focal therapy with high-intensity focused ultrasound for the localized prostate cancer for Asian based on the localization with MRI-TRUS fusion image-guided transperineal biopsy and 12-cores transperineal systematic biopsy: prospective analysis of oncological and functional outcomes

BACKGROUND

We evaluated clinical outcomes of region target focal therapy with high-intensity focused ultrasound (HIFU) for the localized prostate cancer (PCa) based on magnetic resonance imaging-based biopsy and systematic prostate biopsy for Asian.

METHODS

We prospectively recruited patients with localized PCa, located their significant tumors using MRI-transrectal ultrasound (TRUS) elastic fusion image-guided transperineal prostate biopsy and 12-cores transperineal systematic biopsy, and focally treated these regions in which the tumors were located in the prostate using HIFU. Patients' functional and oncological outcomes were analyzed prospectively.

RESULTS

We treated 90 men (median age 70 years; median PSA level 7.26 ng/ml). Catheterization was performed within 24 h after the treatment in all patients. Biochemical disease-free rate was 92.2% during 21 months follow-up when use of Phoenix ASTRO definition. In follow-up biopsy, significant cancer was detected in 8.9% of the patients in un-treated areas. Urinary functions, including international prostate symptom score (IPSS) (P < 0.0001), IPSS quality of life (QOL) (P = 0.001), overactive bladder symptom score (OABSS) (P < 0.0001), EPIC urinary domain (P < 0.0001), maximum urinary flow rate (P < 0.0001), and IIEF-5 (P = 0.001), had significantly deteriorated at 1 month after treatment, but improved to preoperative levels at 3 or 6 months. Rates of erectile dysfunction and ejaculation who had the functions were 86% and 70%, respectively, at 12 months after treatment.

CONCLUSIONS

The present treatment for Asian would have similar oncological and functional outcomes to those in previous reports. Further large studies are required to verify oncological and functional outcomes from this treatment for patients with localized PCa.

Histotripsy: The Next Generation of High-Intensity Focused Ultrasound for Focal Prostate Cancer Therapy

This article reviews the most current methods and technological aspects of high-intensity focused ultrasound (HIFU), which is termed histotripsy. The rationale for focal therapy for prostate carcinoma rather than prostatectomy, which is being used extensively throughout Europe and Asia, is presented, and an argument for why HIFU is the modality of choice for primary therapy and recurrent disease is offered. The article presents a review of the technical advances including higher ultrasound beam energy than current thermal HIFU which allows for more accurate tissue targeting, less collateral tissue damage, and faster treatment times. Finally, the article presents a discussion about the advantage of ultrasound guidance for histotripsy in preference to magnetic resonance imaging guidance primarily based on cost, ease of application, and portability.

Current status and future prospective of focal therapy for localized prostate cancer: development of multiparametric MRI, MRI-TRUS fusion image-guided biopsy, and treatment modalities

Multiparametric magnetic resonance imaging (mpMRI) has been increasingly used to diagnose clinically significant prostate cancer (csPC) because of its usefulness in combination with anatomic and functional data. MRI-targeted biopsy, such as MRI-transrectal ultrasound (TRUS) fusion image-guided prostate biopsy, has high accuracy in the detection and localization of csPC. This novel diagnostic technique contributes to the development of tailor-made medicine as focal therapy, which cures the csPC while preserving the anatomical structures related to urinary and sexual function. In the early days of focal therapy, TRUS-guided systematic biopsy was used for patient selection, and treatment was performed for patients with low-risk PC. With the introduction of mpMRI and mapping biopsy, the treatment range is now determined based on individualized cancer localization. In recent prospective studies, 87.4% of treated patients had intermediate- and high-risk PC. However, focal therapy has two main limitations. First, a randomized controlled trial would be difficult to design because of the differences in pathological features between patients undergoing focal therapy and radical treatment. Therefore, pair-matched studies and/or historical controlled studies have been performed to compare focal therapy and radical treatment. Second, no long-term (≥ 10-year) follow-up study has been performed. However, recent prospective studies have encouraged the use of focal therapy as a treatment strategy for localized PC because it contributes to high preservation of continence and erectile function.

Prospective multicentre study using high intensity focused ultrasound (HIFU) for the focal treatment of prostate cancer: Safety outcomes and complications

PURPOSE

To investigate focal therapy using High Intensity Focused Ultrasound (HIFU) for the treatment of localized prostate cancer (CaP), we analyzed the safety and complications of this procedure.

METHODS

Patients (pts) eligible for this multicenter prospective cohort study suffered from low to intermediate risk localized CaP with no prior treatment. After tumor identification on multiparametric MRI and in prostate biopsy, the lesions were treated with HIFU observing a safety margin of 8 to 10 mm. Adverse events (AE) after 30 and 90 days, as well as the required interventions were assessed and stratified for treatment localizations.

RESULTS

Of the 98 men included in the study in two European centers, 35 (35.7%) experienced AEs in the first 30 days after HIFU intervention with Clavien-Dindo grade ≤ II: 15 pts (15.3%) had a postoperative urinary tract infection and 26 pts (26.5%) a urinary retention. Four pts (4.1%) underwent subsequent intervention (Clavien-Dindo grade IIIa/b). The number of late postoperative complications occurring between 30 and 90 days after intervention was low (2.0%). The highest complication rate was associated with tumors located at the anterior base (50.0%). The inclusion of the urethra in the ablation zone led to AEs in 20 out of 41 cases (48.8%) and represented a significant risk factor for complications within 30 days (odds ratio = 2.53; 95% confidence interval: 1.08-5.96; P = 0.033).

CONCLUSIONS

Focal therapy of CaP lesions with a robotic HIFU-probe is safe and renders an acceptable rate of minor early AEs. The inclusion of the urethra in the ablation zone leads to an increase in early complications and should be avoided whenever possible.

Current status and progress of focal therapy in Asia

PURPOSE OF REVIEW

With the increasing incidence of low-to-intermediate risk of prostate cancer (PCa) by the introduction of prostate-specific antigen (PSA) screening, focal therapy has become one of the promising treatment options in the world. In Asia, same movement are occurring using several technologies including cryoablation, high-intensity focused ultrasound, brachytherapy and irreversible electroporation. However, these are still not common strategies to treat organ-confined PCa. The purpose of this review is to summarize the most updated experience and future direction of focal therapy in Asian countries.

RECENT FINDINGS

The prevalence and diagnosis of PCa are increasing in Asian countries. This increase is related to various factors including the widespread implementation of PSA testing and lifestyle changes to more Westernized diets. With the increasing detection rate of early stage PCa, overdetection and overtreatment are recognized even in Asia. In this setting, accumulating data on multiparametric MRI and MRI-targeted biopsy as well as MRI-transrectal ultrasound (TRUS) fusion biopsy suggest the potential in improving the detection of clinically significant PCa in Asia. Furthermore, targeted focal therapy has emerged as a promising treatment strategy aiming for both providing oncological outcome and maintaining functional preservation in many Asian countries.

SUMMARY

At present, focal therapy is not a current standard choice for the treatment of localized PCa in Asian countries. However, with the increase of localized PCa and patient's preference for less invasive treatment with preservation of organ-function, focal therapy should become a definite treatment option for localized PCa in Asia.

Patient-reported outcomes after treatment for clinically localized prostate cancer: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review is to assess the impact of primary treatments with curative intention in patients with localized prostate cancer, measured with Patient-Reported Outcomes (PROs), and to examine differences among modalities within treatments.

METHODS

We conducted a systematic literature search for January 2005-March 2017 following PRISMA guidelines, including longitudinal studies measuring disease-specific PROs in localized prostate cancer patients with a follow-up from pre- to post-treatment (≥1 year). Two reviewers independently extracted data and assessed risk of bias. The study is registered in PROSPERO: CRD42015019747.

RESULTS

Of 148 identified studies, 60 were included in the meta-analyses. At the 1st year, radical prostatectomy patients showed small urinary irritative-obstructive improvement (0.37SD 95%CI 0.30, 0.45), but large deterioration for sexual function and incontinence with high heterogeneity (I² = 77% and 93%). Moderate worsening in external radiotherapy patients for sexual function (-0.46SD 95%CI -0.55, -0.36), small urinary incontinence (-0.16SD 95%CI -0.23, -0.09) and bowel impairment (-0.31SD 95%CI -0.39, -0.23). Brachytherapy patients presented small deterioration in urinary incontinence (-0.29SD 95%CI -0.39, -0.19), irritative obstructive symptoms (-0.35SD 95%CI -0.47, -0.23), sexual function (-0.12SD 95%CI -0.24, -0.002), and bowel bother (-0.27SD 95%CI -0.42, -0.11). These patterns persisted up to the 5th year. High-intensity focused ultrasound and active surveillance only have results at 1st year, showing no statistically significant worsening.

CONCLUSIONS

No remarkable differences in PRO appeared between modalities within each treatment. Nowadays, available evidence supports brachytherapy as possible alternative to radical prostatectomy for patients seeking an attempted curative treatment limiting the risk for urinary incontinence and sexual dysfunction.

[FOCAL THERAPY WITH HIGH-INTENSITY FOCUSED ULTRASOUND FOR THE LOCALIZED PROSTATE CANCER BASED ON THE LOCALIZATION WITH MRI-TRUS FUSION IMAGE-GUIDED BIOPSY: 1-YEAR PROSPECTIVE STUDY]

(Objective) To evaluate the efficacy and invasiveness of focal therapy with transrectal high-intensity focused ultrasound (HIFU) for localized prostate cancer based on spatial location of significant cancer with magnetic resonance imaging (MRI)-transrectal ultrasound (TRUS) fusion image-guided biopsy. (Methods) Patients with low- and intermediate-risk significant prostate cancer who were followed-up at least 1 year, were prospectively recruited. The spatial localization of the significant cancer was determined by MRI-TRUS fusion image-guided transperineal prostate biopsy. Focal therapy targeting the regions of significant cancer was performed by transrectal HIFU using a Sonablate^® 500 (SonaCare Medical, Indianapolis, IN, USA). Serum prostate-specific antigen (PSA) kinetics, multi-parametric MRI, and MRI-TRUS fusion image-guided prostate biopsy were analyzed to determine the treatment efficacy. Questionnaires and uroflowmetry were performed to evaluate the invasiveness. (Results) Ten men with median age of 67 years (range, 48-79), median PSA level of 7.07 ng/ml (range, 4.67-15.99), median prostate volume of 25 ml (range, 19-36) were treated. Median operative time was 29.5 minutes (range, 14-85). Catheterization was performed within 24 hours after the treatment in all patients. The median PSA concentration significantly decreased to 1.35 ng/ml (p<0.0001) at 3 months after the treatment. Contrast-enhanced T1-weighted MRI showed the disappearance of blood flow in all targeted regions of the prostate. MRI-TRUS fusion image-guided prostate biopsy detected the significant cancer out of the treated region in 1 patient. In urinary function, residual urine was significantly increased at 3 months after the treatment (p=0.007), but improved to the preoperative level (p=0.411). There was no significant deterioration in IPSS, IPSS QOL, OABSS, and the urinary function domain of EPIC between before and 3, 6, 9, and 12 months after the treatment. In sexual function, there was no significant difference in IIEF-5 and the sexual domain of EPIC between before and 3, 6, 9, and 12 months after the treatment. In quality of life, there was no significant difference in EPIC and SF-36 between before and 3, 6, 9, and 12 months after the treatment. The proportion of men with erections sufficient for penetration and ejaculation remained unchanged at 100% (5 of 5 patients). No serious adverse events were recorded. (Conclusions) The focal therapy with HIFU has the potential to provide accurate treatment with low morbidity in patients with localized prostate cancer. Further large studies are required to investigate the effects of the focal therapy with HIFU for analysis of oncological and functional outcomes in patients with localized prostate cancer.

Partial Gland Treatment of Prostate Cancer Using High-Intensity Focused Ultrasound in the Primary and Salvage Settings: A Systematic Review

PURPOSE

Advances in prostate imaging, biopsy and ablative technologies have been accompanied by growing enthusiasm for partial gland ablation, particularly using high-intensity focused ultrasound, to treat prostate cancer. Preserving noncancerous prostate tissue and minimizing damage to the neurovascular bundles and external urethral sphincter may improve functional outcomes.

MATERIALS AND METHODS

A systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using a combination of MeSH® terms, free text search and examination of relevant bibliographies using MEDLINE® and Embase® from the inception of each database through October 10, 2016. We excluded studies describing exclusively whole gland ablation, case reports and series where treatment was followed by immediate resection.

RESULTS

A total of 13 studies that enrolled 543 patients were included. Of the studies 11 were performed in the primary setting and 2 in the salvage setting. Median followup ranged from 6 months to 10.6 years. Rates of posttreatment erectile dysfunction and urinary incontinence ranged from 0% to 48% and 0% to 50%, respectively, with definitions varying by study. Overall there were 254 reported complications. Marked heterogeneity between studies limited the ability to pool results regarding functional and oncologic outcomes. A total of 76 patients (14%) subsequently received further oncologic treatment.

CONCLUSIONS

Early evidence suggests that partial gland ablation is a safe treatment option for men with localized disease. Longer term data are needed to evaluate oncologic efficacy and functional outcomes, and will aid in identifying the optimal candidates for therapy. Standardization of outcomes definitions will allow for better comparison between studies and among treatment modalities.