Prostate swelling and shift during high intensity focused ultrasound: implication for targeted focal therapy

Current status and future outlook of ultrasound treatment for prostate cancer

Radical prostatectomy and radiation therapy are the standard treatment options for localized prostate cancer (PC). However, radical prostatectomy may cause the deterioration of urinary and sexual function, and radiation-induced hemorrhagic cystitis and severe rectal bleeding are risk factors for fatal conditions in patients after radiation therapy. With the recent development of magnetic resonance imaging (MRI) for the localization of clinically significant PC (csPC) and treatment modalities, "focal therapy", which cures csPC while preserving anatomical structures related to urinary and sexual functions, has become a minimally invasive treatment for localized PC. Based on the clinical results of transrectal high-intensity focused ultrasound (HIFU) for localized PC in the whole gland and focal therapy, HIFU is considered an attractive treatment option for focal therapy. Recently, the short-term clinical results of transurethral high-intensity directional ultrasound (HIDU) have been reported. With the resolution of some issues, HIDU may be commonly used for PC treatment similar to HIFU. Because HIFU and HIDU have limitations regarding the treatment of patients with large prostate calcifications and large prostate volumes, the proper use of these modalities will enable the treatment of any target area in the prostate. To establish a standard treatment strategy for localized PC, pair-matched and historically controlled studies are required to verify the oncological and functional outcomes of ultrasound treatment for patients with localized PC.

Risk Factors for Severe Erectile Dysfunction after Focal Therapy with High-Intensity Focused Ultrasound for Prostate Cancer

The present study aimed to analyze the effect of predisposing clinical factors for severe erectile dysfunction (ED) in patients treated with focal therapy using high-intensity focused ultrasound (HIFU) for localized prostate cancer (PC). Patients without severe ED (International Index of Erectile Function-5 [IIEF-5] score ≥ 8) before focal HIFU therapy were included. A total of 92 of the 240 patients met the inclusion criteria and were included. The rate of severe ED (IIEF-5 ≤ 7) was 36% 12 months after treatment. Multivariable logistic regression analysis showed that the pre-procedural lower IIEF-5 score (odds ratio [OR] 0.812, p = 0.005), the pre-procedural lower score of the sexual domain of the Expanded Prostate Cancer Index Composite (OR 0.960, p = 0.038), and the treatment of the edge of the peripheral zone (PZ) in proximity to the neurovascular bundle (NVB) [treated vs. untreated, OR 8.048, p = 0.028] were significant risk factors for severe ED at 12 months after treatment. In conclusion, pre-procedural lower erectile function and treatment of the part in proximity to the NVB were significant risk factors for severe ED after focal therapy.

Focal prostate cancer therapy in the era of multiparametric MRI: a review of options and outcomes

BACKGROUND

The goal of prostate cancer focal therapy is to achieve oncologic control while reducing the rate of adverse events associated with whole-gland treatments. Numerous focal therapy modalities are currently available with early data demonstrating highly variable rates of cancer control and preservation of sexual/urinary function.

METHODS

All English language clinical trial publications evaluating various focal therapies for localized prostate cancer were reviewed. The literature search was limited to studies from the modern era of MRI-guided treatment, as MRI is hypothesized to improve tumor localization and targeting. Primary outcomes were post-treatment cancer-free rates, in-field/out-of-field recurrence rates, and rates of conversion to radical therapy. Secondary outcomes were related to functional status and adverse events.

RESULTS

Numerous focal therapies were identified with clinical data including high-intensity focused ultrasound, transurethral ultrasound ablation, focal laser ablation, focal cryotherapy, irreversible electroporation, and photodynamic therapy. Recurrence rates among all technologies were low to moderate (0-51%) and rates of freedom from radical treatment were highly variable (46-98%). Rates of erectile dysfunction and incontinence generally ranged from 0 to 44% and 0 to 12%, respectively, with variability between focal therapy modalities. Caution should be exercised when comparing studies as outcomes are strongly associated with patient selection. No individual focal therapy is currently recommended by society guidelines. Randomized controlled trials are ongoing in search of a standard of care.

CONCLUSION

For localized MRI-visible prostate cancer, early clinical trial data demonstrate that focal therapy can provide good to moderate cancer control while having preferable side effect profiles compared to whole-gland treatments. While current studies do not make head-to-head comparisons between technologies, early data suggest a potential for these technologies to provide adequate cancer control in a well-selected patient population. The oncologic outcomes of some focal therapies appear promising; however, longer-term follow-up data are needed to assess the durability of early outcomes.

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.

High-Intensity Focused Ultrasound (HIFU) Focal Therapy for Localized Prostate Cancer with MRI-US Fusion Platform

Objective

The study aimed at investigating the outcome of prostate HIFU focal therapy using the MRI-US fusion platform for treatment localization and delivery.

Methods

It is a prospectively designed case series of HIFU focal therapy for localized prostate cancer. The inclusion criteria include clinical tumor stage ≤T2, visible index lesion on multiparametric MRI less than 20 mm in diameter, absence of Gleason 5 pattern on prostate biopsy, and PSA ≤ 20 ng/ml. HIFU focal therapy was performed in the conventional manner in the beginning 50% of the series, whereas the subsequent cases were performed with MRI-US fusion platform. The primary outcome was treatment failure rate which is defined by the need of salvage therapy. Secondary outcomes included tumor recurrence in follow-up biopsy, PSA change, perioperative complications, and postoperative functional outcomes.

Results

Twenty patients underwent HIFU focal ablation. HIFU on an MRI-US fusion platform had a trend of a longer total operative time than the conventional counterpart (124.2 min vs. 107.1 min, p=0.066). There was no difference in the mean ablation volume to lesion volume ratio between the two. The mean PSA percentage change from baseline to 6-month is more significant in the conventional group (63.3% vs. 44.6%, p=0.035). No suspicious lesion was seen at 6-month mpMRI in all 20 patients. Two patients, one from each group, eventually underwent radical treatment because of the presence of clinically significant prostate cancer in the form of out-of-field recurrences during follow-up biopsy. No significant difference was observed before and after HIFU concerning uroflowmetry, SF-12 score, and EPIC-26 score. It was observed that energy used per volume was positively correlated with PSA density of the patient (r = 0.6364, p=0.014).

Conclusion

In conclusion, HIFU with conventional or MRI-US fusion platform provided similar oncological and functional outcomes.

Oncological and functional outcome after partial prostate HIFU ablation with Focal-One®: a prospective single-center study

BACKGROUND

We aimed to evaluate oncological and functional outcomes of index lesion HIFU ablation with Focal-One^®.

MATERIALS AND METHODS

We prospectively assessed treatment-naïve men with localized prostate cancer between 2017 and 2019. Inclusion criteria were stage cT ≤ 2, ≥5 years of life expectancy, grade group ≤3. Multiparametric magnetic resonance was performed before ablation. Patients with a prostate volume of ≥80 ml underwent debulking. Treatment failure was defined as a histologically confirmed tumor that required salvage treatment or androgen deprivation therapy.

RESULTS

One hundred and eighty nine patients were enrolled. Data are presented as median and Interquartile Range (IQR). Median age was 70(11) years. Median baseline PSA was 5.8(3) ng/ml. Fourteen (7.4%) patients had prostate debulking before ablation. 104 (55%) patients underwent targeted ablation, 45 (23.8%) extended targeted ablation, 31 (16.4%) hemiablation, and 9 (4.8%) extended hemiablation. Median targeted ablated volume was 14(9) ml. Ninety-three complications occurred in 63/189 (33.3%) patients within 90 days. There were 77/93 (82.8%) minor (Clavien grade 1-2) and 16/93 (17.2%) major complications (Clavien grade 3a). Thirty-nine patients suffered from genito-urinary infections (Clavien grade 2). Fifteen patients required transurethral resection of the prostate/urethrotomy for recurrent urinary retention (Clavien grade 3a). One patient developed a recto-urethral fistula (Clavien grade 3a) and two long-lasting urinary incontinence. Median PSA nadir was 2.2(2.9) ng/ml. At a median follow-up of 29(15) months, 21/177 (11.9%) patients were treatment failures, 26 on monitoring, and 26 had a further ablation. Multivariable logistic regression found that failure patients had higher PSA (7.8 vs 5.7 ng/ml,p0.001) and double PSA nadir (4.8 vs 2.0 ng/ml, p < 0.001). Higher PSA nadir correlated with a 74% higher probability of failure (OR 1.74 95% CI 1.40-2.16). Cancer in the anterior stroma increased the odds of failure of three folds (OR 3.36 95% CI 1.18-9.53). Two mixed effect models (one for IPSS and one for IEEF-15) were estimated and they showed that time reaches the statistical significance coefficient only for the IEEF-15, meaning that subsequent evaluations of the indicators were significantly lower at each time point.

CONCLUSIONS

Index lesion HIFU ablation demonstrated satisfactory early oncological outcome but anteriorly located tumors had inadequate ablation. Urinary function was well preserved. Sexual function slightly decreased during follow-up.

Analysis of oncological outcomes of whole-gland therapy with high-intensity focused ultrasound for localized prostate cancer in clinical and technical aspects: a retrospective consecutive case-series analysis with a median 5-year follow-up

PURPOSE

This study aimed to analyze technical and clinical factors related to oncological outcomes in patients with localized prostate cancer (PC) who were treated with whole-gland high-intensity focused ultrasound (HIFU).

MATERIALS AND METHODS

From 2007-2014, patients diagnosed with localized PC who underwent whole-gland HIFU were consecutively included retrospectively. Biochemical failure was defined according to the Phoenix ASTRO guidelines. The relationship between oncological outcomes and technical and clinical factors was evaluated.

RESULTS

The study cohort included 428 patients. The median age was 67 years, and the median prostate-specific antigen level was 7.61 ng/mL. Patient risk classifications were low (n = 102), intermediate (n = 240), and high (n = 86). Biochemical disease-free survival rates of patients with HIFU for localized PC in the total, low-, intermediate-, and high-risk groups according to D'Amico risk groups over a median follow-up period of 5 years (range 9-144) were 68.4%, 80.4%, 65.6%, and 61.6%, respectively. In multivariate logistic regression analyses to predict biochemical failure of the treatment, neoadjuvant hormonal therapy (NHT) in the high-risk group (OR 0.225, p = 0.015), and compression method in the low- (OR 0.178, p = 0.030), intermediate- (OR0.291, p < 0.0001), and high-risk (OR 0.316, p = 0.049) groups were significant factors that reduced the risk of biochemical failure after treatment. There were no significant differences in complications between patients treated with compression and those treated conventionally.

CONCLUSIONS

NHT may potentially improve oncological outcomes for patients in the high-risk group, and compression methods can improve the oncological outcomes of whole-gland therapy with HIFU.

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.

Focal HIFU therapy for anterior compared to posterior prostate cancer lesions

Objective

To compare cancer control in anterior compared to posterior prostate cancer lesions treated with a focal HIFU therapy approach.

Materials and methods

In a prospectively maintained national database, 598 patients underwent focal HIFU (Sonablate^®500) (March/2007–November/2016). Follow-up occurred with 3-monthly clinic visits and PSA testing in the first year with PSA, every 6–12 months with mpMRI with biopsy for MRI-suspicion of recurrence. Treatment failure was any secondary treatment (ADT/chemotherapy, cryotherapy, EBRT, RRP, or re-HIFU), tumour recurrence with Gleason ≥ 3 + 4 on prostate biopsy without further treatment or metastases/prostate cancer-related mortality. Cases with anterior cancer were compared to those with posterior disease.

Results

267 patients were analysed following eligibility criteria. 45 had an anterior focal-HIFU and 222 had a posterior focal-HIFU. Median age was 64 years and 66 years, respectively, with similar PSA level of 7.5 ng/ml and 6.92 ng/ml. 84% and 82%, respectively, had Gleason 3 + 4, 16% in both groups had Gleason 4 + 3, 0% and 2% had Gleason 4 + 4. Prostate volume was similar (33 ml vs. 36 ml, p = 0.315); median number of positive cores in biopsies was different in anterior and posterior tumours (7 vs. 5, p = 0.009), while medium cancer core length, and maximal cancer percentage of core were comparable. 17/45 (37.8%) anterior focal-HIFU patients compared to 45/222 (20.3%) posterior focal-HIFU patients required further treatment (p = 0.019).

Conclusion

Treating anterior prostate cancer lesions with focal HIFU may be less effective compared to posterior tumours.

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.

An Exploratory Study of Dose Escalation vs Standard Focal High-Intensity Focused Ultrasound for Treating Nonmetastatic Prostate Cancer

Objective: Analysis of treatment success regarding oncological recurrence rate between standard and dose escalation focal high-intensity focused ultrasound (HIFU) of prostate cancer. Materials and Methods: In this analysis of our prospectively maintained HIFU (Sonablate^® 500) database, 598 patients were identified who underwent a focal HIFU (Sonablate 500) between March 2007 and November 2016. Follow-up occurred with 3-monthly clinic visits and prostate specific antigen (PSA) testing in the first year. Thereafter, PSA was measured 6-monthly or annually at least. Routine and for-cause multiparametric MRI (mpMRI) was conducted with biopsy for MRI suspicion of recurrence. Treatments were delivered in a quadrant or hemiablation fashion depending on the gland volume as well as tumor volume and location. Before mid-2015, standard focal HIFU was used (two HIFU blocks); after this date, some urologists conducted dose escalation focal HIFU (three overlapping HIFU blocks). Propensity matching was used to ensure two matched groups, leading to 162 cases for this analysis. Treatment failure was defined by any secondary treatment (systemic therapy, cryotherapy, radiotherapy, prostatectomy, or further HIFU), metastasis from prostate cancer without further treatment, tumor recurrence with Gleason score ≥7 (≥3 + 4) on prostate biopsy without further treatment, or prostate cancer-related mortality. Complications and side-effects were also compared. Results: Median age was 64.5 years (interquartile range [IQR] 60-73.5) in the standard focal-HIFU group and 64.5 years (IQR 60-69) in the dose-escalation group. Median prostate volume was 37 mL (IQR 17-103) in the standard group and 47.5 mL (IQR 19-121) in the dose-escalation group. As tumor volume on mpMRI and Gleason score were major matching criteria, these were identical with 0.43 mL (IQR 0.05-2.5) and Gleason 3 + 3 = 6 in 1 out of 32 (3%), 3 + 4 = 7 in 27 out of 32 (84%), and 4 + 3 = 7 in 4 out of 32 (13%). Recurrence in treated areas was found in 10 out of 32 (31%) when standard treatment zones were applied, and in 6 out of 32 (19%) of dose-escalation focal HIFU (p = 0.007). Conclusion: This exploratory study shows that dose escalation focal HIFU may achieve higher rates of disease control compared with standard focal HIFU. Further prospective comparative studies are needed.

Which technology to select for primary focal treatment of prostate cancer?-European Section of Urotechnology (ESUT) position statement

BACKGROUND

With growing interest in focal therapy (FT) of prostate cancer (PCa) there is an increasing armamentarium of treatment modalities including high-intensity focused ultrasound (HIFU), cryotherapy, focal laser ablation (FLA), irreversible electroporation (IRE), vascular targeted photodynamic therapy (VTP), focal brachytherapy (FBT) and stereotactic ablative radiotherapy (SABR). Currently there are no clear recommendations as to which of these technologies are appropriate for individual patient characteristics. Our intention was to review the literature for special aspects of the different technologies that might be of advantage depending on individual patient and tumour characteristics.

METHODS

The current literature on FT was screened for the following factors: morbidity, repeatability, tumour risk category, tumour location, tumour size and prostate volume and anatomical issues. The ESUT expert panel arrived at consensus regarding a position statement on a structured pathway for available FT technologies based on a combination of the literature and expert opinion.

RESULTS

Side effects were low across different studies and FT modalities with urinary continence rates of 90-100% and erectile dysfunction between 5 and 52%. Short to medium cancer control based on post-treatment biopsies were variable between ablative modalities. Expert consensus suggested that posterior lesions are better amenable to FT using HIFU. Cryotherapy provides best possible outcomes for anterior tumours. Apical lesions, when treated with FBT, may yield the least urethral morbidity.

CONCLUSIONS

Further prospective trials are required to assess medium to long term disease control of different ablative modalities for FT. Amongst different available FT modalities our ESUT expert consensus suggests that some may be better for diffe`rent tumour locations. Tumour risk, tumour size, tumour location, and prostate volume are all important factors to consider and might aid in designing future FT trials.

[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.

[Evaluation and results of ablative therapies in prostate cancer]

OBJECTIVE

To perform a state of the art about methods of evaluation and present results in ablative therapies for localized prostate cancer.

METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 102 articles were analysed.

RESULTS

Analyse the results of ablative therapies is presently difficult considering the heterogeneity of indications, techniques and follow-up. However, results from the most recent and homogeneous studies are encouraging. Oncologically, postoperative biopsies (the most important criteria) are negative (without any tumor cells in the treated area) in 75 to 95%. Functionally, urinary and sexual pre-operative status is spared (or recovered early) in more than 90% of the patients treated. More and more studies underline also the correlation between the results and the technique used considering the volume of the gland and, moreover, the "index lesion" localization.

CONCLUSION

The post-treatment pathological evaluation by biopsies (targeted with MRI or, perhaps in a near future, with innovative ultrasonography) is the corner stone of oncological evaluation of ablative therapies. Ongoing trials will allow to standardize the follow-up and determine the best indication and the best techniques in order to optimize oncological and functional results for each patient treated.

[Interest using 3D ultrasound and MRI fusion biopsy for prostate cancer detection]

INTRODUCTION

The strategic therapy for prostate cancer depends on histo-pronostics data, which could be upgraded by obtaining targeted biopsies (TB) with MRI (magnetic resonance imagery) fusion 3D ultrasound.

OBJECTIVES

To compare diagnostic yield of image fusion guided prostate biopsy using image fusion of multi-parametric MRI (mpMRI) with 3D-TRUS.

MATERIALS AND METHODS

Between January 2010 and April 2013, 179 consecutive patients underwent outpatient TRUS biopsy using the real-time 3D TRUS tracking system (Urostation™). These patients underwent MRI-TRUS fusion targeted biopsies (TB) with 3D volume data of the MRI elastically fused with 3D TRUS at the time of biopsy.

RESULTS

A hundred and seventy-three patients had TBs with fusion. Mean biopsy core per patient were 11.1 (6-14) for SB and 2.4 (1-6) for TB. SBs were positive in 11% compared to 56% for TB (P<0.001). TB outperformed systematic biopsy(SB) in overall any cancer detection rate, detection of clinically significant cancer (58% vs. 36%), cancer core length (6.8mm vs. 2.8mm), and cancer rate per core (P<0.001). In multivariable logistic regression, with TB we have more chance to find a clinically significant cancer (OR:3.72 [2-6.95]). When both TRUS and MRI are positive, there is 2.73 more chance to find a clinically significant cancer.

CONCLUSION

MR/TRUS elastic fusion-guided biopsies outperform systematic random biopsies in diagnosing clinically significant cancer. Ability of interpretation of real-time TRUS is essential to perform the higher level of MR/US fusion and should be use for active surveillance.

LEVEL OF PROOF

4.

A Review on Real-Time 3D Ultrasound Imaging Technology

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail.

Single application of high-intensity focused ultrasound as primary therapy of localized prostate cancer: Treatment-related predictors of biochemical outcomes

Objective

Recent reports on high-intensity focused ultrasound (HIFU) treatment of localized prostate cancer suggest that preoperative risk groups of tumor recurrence are strong predictors of oncological outcomes. The purpose of this study is to determine the prognostic significance of treatment-related factors in relation to patient characteristics for biochemical outcomes after HIFU.

Methods

This retrospective single-center study included patients treated from December 2002 to December 2010 for localized prostate cancer with two generations of Ablatherm^® HIFU devices (A1 and A2). All the patients underwent single HIFU treatment session under the concept of whole-gland therapy. Prostate surgery was performed before HIFU to downsize enlarged glands. Androgen deprivation therapy (ADT) was discontinued before HIFU. Biochemical failure (BCF) was defined as prostate specific antigen (PSA) nadir + 1.2 ng/mL (Stuttgart definition). Predictors of BCF were determined using Cox regression models. As covariates, patient-related factors (age, tumor characteristics, ADT) were compared with treatment-related factors (prostate volume, HIFU device generation, conduct of therapy, prostate edema, patient movement, anesthetic modalities).

Results

Three hundred and twenty-three (98.8%) out of 327 consecutive patients were evaluable for BCF. Median (interquartile range) follow-up was 51.2 (36.6-80.4) months. The overall BCF-rate was 23.8%. In multivariate analyses, higher initial PSA-values (Hazard ratio [HR]: 1.03; p < 0.001) and higher D'Amico risk stages (HR: 3.45; p < 0.001) were patient-related predictors of BCF. Regarding treatment-related factors, the A2 HIFU device was associated with a decreased risk of BCF (HR: 0.51; p = 0.007), while prostate edema had an adverse effect (HR: 1.8; p = 0.027). Short follow-up and retrospective study design are the primary limitations.

Conclusion

Success in a single HIFU session depends not merely on tumor characteristics, but also on treatment-related factors. Ablation is more efficacious with the technically advanced A2 HIFU device. Heat-induced prostate edema might adversely affect the outcome.

Opportunities for targeted focal treatment in Japan

PURPOSE OF REVIEW

Widespread prostate-specific antigen screening has led to an increase in prostate cancer diagnoses in Asian populations, reflecting changes in socioeconomic status and epidemiological features in these countries. In this setting, the present review explores opportunities for target focal therapy in Japan.

RECENT FINDINGS

Our review examines several topics relating to focal therapy in Asia, and discusses the current status of prostate cancer diagnosis and treatment in that region. First, we summarize the prevalence of prostate cancer in Asian populations. Second, we examine prostate cancer diagnosis and treatment options such as mapping biopsy and MRI fusion biopsy in Japan. Third, we review treatment strategies for localized prostate cancer, especially robotic-assisted surgery, active surveillance, and high-intensity focused ultrasound. Lastly, we discuss the potential for focal therapy in Japan.

SUMMARY

The number of localized prostate cancer patients is expected to increase in Asia. Accordingly, the need for precise diagnosis in terms of localization of prostate cancer foci will also expand. MRI fusion target biopsies are being performed in Asia, particularly in some Japanese academic institutions, but as pilot studies. In recent years, an increase in robotic-assisted surgery in East Asia has yielded new options in prostate cancer treatment. Although active surveillance is a practical choice for low-risk prostate cancer in some Asian countries, focal therapy is expected to see increasing interest as another alternative in Japan.

High-intensity focused ultrasound for the treatment of prostate cancer: A prospective trial with long-term follow-up

OBJECTIVE

High-intensity focused ultrasound (HIFU) is a minimally invasive treatment for prostate cancer. Data from the literature show promising oncological outcomes with a favourable side-effect profile. The aim of this study was to re-evaluate and bring up to date the follow-up of a previously published, prospective trial on HIFU as the primary treatment for prostate cancer.

MATERIALS AND METHODS

Between 2004 and 2007, 163 consecutive men with T1-T3N0M0 prostate cancer underwent HIFU with the Sonablate 500. Follow-up included prostate-specific antigen (PSA) tests every 3 months after treatment and a random prostate biopsy at 6 months. Failure was defined according to positive findings at the 6 month biopsy and biochemical failure was defined according to the Phoenix criteria. Biochemical-free survival, metastasis-free survival and cancer-specific survival were calculated by Kaplan-Meier curves.

RESULTS

Median follow-up was 72.0 months. Of the 160 evaluable patients, 104 (65%) were biochemically disease free; in low- to intermediate-risk disease, on Kaplan-Meier analysis the 8 year biochemical-non-evidence of disease (bNED), metastasis-free survival and cancer-specific survival rates were 69.6%, 81.3%, 100% and 40.5%, 60.6%, 100%, respectively. A PSA nadir below 0.40 ng/ml and risk stratification have an independent predictive value for bNED and metastasis-free survival.

CONCLUSIONS

A long-term favourable outcome of HIFU is associated with careful patient selection, with low- to intermediate-risk disease being the ideal case. A low postoperative PSA nadir is a predictor of long-term bNED.

Urodynamic evaluation after high-intensity focused ultrasound for patients with prostate cancer

This prospective study assesses the impact of high-intensity focused ultrasound (HIFU) on lower urinary tract by comparing pre- and postoperative symptoms and urodynamic changes. Thirty consecutive patients with clinically organ-confined prostate cancer underwent urodynamic study before HIFU and then at 3–6 months after surgery. Continence status and symptoms were analyzed by means of International Prostate Symptoms Score IPSS and International Index Erectile Function IIEF5. As a result, there were a significant improvement in bladder outlet, maximum flow at uroflowmetry, and reduction in postvoid residual PVR at 6-month follow-up and a concomitant significant reduction of detrusor pressure at opening and at maximum flow. De novo overactive bladder and impaired bladder compliance were detected in 10% of patients at 3 months, with progressive improvement at longer follow-up. Baseline prostate volume and length of the procedure were predictors of 6-month IPSS score and continence status. In conclusion, following HIFU detrusor overactivity, decreased bladder compliance and urge incontinence represent de novo dysfunction due to prostate and bladder neck injury during surgery. However, urodynamic study shows a progressive improvement in all storage and voiding patterns at 6-month follow-up. Patients with high prostate volume and long procedure length suffered from irritative symptoms even at long term.