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

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.

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.

Real-Time and Delayed Imaging of Tissue and Effects of Prostate Tissue Ablation

PURPOSE OF REVIEW

Prostate ablation is increasingly being utilized for the management of localized prostate cancer. There are several energy modalities with varying mechanism of actions which are currently used for prostate ablation. Prostate ablations, whether focal or whole gland, are performed under ultrasound and/or MRI guidance for appropriate treatment plan execution and monitoring. A familiarity with different intraoperative imaging findings and expected tissue response to these ablative modalities is paramount. In this review, we discuss the intraoperative, early, and delayed imaging findings in prostate from the effects of prostate ablation.

RECENT FINDINGS

The monitoring of ablation both during and after the therapy became increasingly important due to the precise targeting of the target tissue. Recent findings suggest that real-time imaging techniques such as MRI or ultrasound can provide anatomical and functional information, allowing for precise ablation of the targeted tissue and increasing the effectiveness and precision of prostate cancer treatment. While intraprocedural imaging findings are variable, the follow-up imaging demonstrates similar findings across various energy modalities. MRI and ultrasound are two of the frequently used imaging techniques for intraoperative monitoring and temperature mapping of important surrounding structures. Follow-up imaging can provide valuable information about ablated tissue, including the success of the ablation, presence of residual cancer or recurrence after the ablation. It is critical and helpful to understand the imaging findings during the procedure and at different follow-up time periods to evaluate the procedure and its outcome.

Comparing 12-core and 20-core biopsy for prostate cancer diagnosis with transperineal MR/US fusion biopsy: assessing the effective number of systemic cores using propensity score matching

PURPOSE

For transperineal (TP) prostate biopsy, target biopsy for visible lesions on MRI is important, but there is no consensus of the number of systemic biopsy cores. Our study aimed to confirm the diagnostic efficiency of 20-core systemic biopsy by comparison with 12-core using propensity score matching (PSM).

METHODS

The 494 patients conducted the naive TP biopsy were retrospectively analyzed. There were 293 patients with 12-core biopsy and 201 patients with 20-core biopsy. PSM was performed for minimizing confounding variables, and the established effects' value was analyzed for 'index-positive or negative' clinically significant prostate cancer (csPCa) (Index means PIRADS Score ≥ 3 on multiparametric prostate MRI).

RESULTS

At 12-core biopsy, there were 126 cases of prostate cancer (43.0%), and 97 cases of csPCa (33.1%). At 20-core biopsy, there were 91 cases (45.3%) and 63 cases (31.3%). After propensity score matching, for index-negative csPCa, the estimated odds ratio was 4.03 (95% CI 1.35-12.09, p value 0.0128), and for index-positive csPCa, the estimated odds ratio was 0.98 (95% CI 0.63-1.52, p value 0.9308).

CONCLUSIONS

The 20-core biopsy did not show a higher detection rate for csPCa in comparison with the 12-core biopsy. However, when MRI did not show a suspicious lesion, 20-core biopsy showed higher odd ratio in comparison with 12-core biopsy. Therefore, if there is a suspicious lesion in MRI, 20-core biopsy is excessive and 12-core biopsy is sufficient. Whereas if there is no suspicious lesion in MRI, it is better to proceed with 20-core biopsy.

Oncological results and cancer control definition in focal therapy for Prostate Cancer: a systematic review

INTRODUCTION

Focal therapy (FT) is a promising alternative to whole-gland treatments for Localized Prostate Cancer. Ten different FT modalities have been described in literature. However, FT is not yet recommended by the International Guidelines, due to the lack of robust data on Oncological Outcomes. The objective of our Narrative Review is to evaluate the oncological profile of the available FT modalities and to offer a comprehensive overview of the definitions of Cancer Control for FT.

MATERIAL AND METHODS

Literature search was performed on 21^st February 2023 using PubMed, EMBASE, and Scopus, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA). Articles reporting whole gland-treatments were excluded. All articles reporting oncological outcomes were included.

RESULTS

One-hundred-twenty-four studies, reporting data on more than 8000 patients treated with FT, were included. Overall, 40 papers were on High Intensity Focal Ultrasound (HIFU), 24 on Focal Cryotherapy, 13 on Irreversible Electroporation (IRE), 11 on Focal brachytherapy, 10 on Focal Laser Ablation (FLA), 8 on Photo-Dynamic Therapy (PDT), 3 on Microwave ablation, 3 on Robotic Partial Prostatectomy, 2 on bipolar Radio Frequency Ablation (bRFA), 1 on Prostatic Artery Embolization (PAE) and 9 comparative papers. Overall, the Biochemical Recurrence (BCR) rate ranged from 0% (Focal Brachytherapy) to 67.5% (HIFU); the Salvage treatment rate ranged from 1% (IRE) to 54% (HIFU) considering re-treatment with FT and from 0% (Focal Brachytherapy) to 66.7% considering standard Radical Treatments. There is no univocal definition of Cancer Control, however the "Phoenix criteria" for BCR were the most commonly used.

CONCLUSIONS

FT is a promising alternative treatment for localized prostate cancer in terms of Oncological Outcomes, however there is a wide heterogeneity in the definition of cancer control, the reporting of oncological outcomes and a lack of high-quality clinical trials. Solid comparative studies with standard treatments and an unambiguous consensus on how to describe Cancer Control in the field of Focal Therapy are needed.

Functional outcomes and safety of focal therapy for prostate cancer: a systematic review on results and patient-reported outcome measures (PROMs)

INTRODUCTION

Focal therapy (FT) is a promising alternative with curative intent for Low- to Intermediate-risk localized Prostate Cancer (PCa), claiming better functional outcomes and safety profile than standard whole-gland treatments. Ten different FT modalities have been described in the literature. The objective of our narrative review is to evaluate the safety profile and functional outcomes of these different modalities and the current most used tools of assessment for those outcomes.

MATERIAL AND METHODS

Literature search was performed on 21st February 2023 using PubMed, EMBASE, and Scopus, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA). Articles reporting whole-gland treatments were excluded. All articles reporting functional outcomes were included.

RESULTS

One-hundred-seven studies, reporting data on 6933 patients, were included (26 on High Intensity Focal Ultrasound, 22 on Focal Cryotherapy, 14 on Irreversible Electroporation, 11 on Focal brachytherapy, 10 on Focal Laser Ablation, 8 on Photodynamic Therapy, 3 on Microwave ablation, 3 on Robotic Partial Prostatectomy, 2 on bipolar Radio Frequency Ablation, 1 on Prostatic Artery Embolization, and 7 studies comparing different FTs). Post-operative pad-free rate ranged between 92.3-100%. Greater heterogeneity exists considering the Change in Erectile Function, with Changing in Erectile function- rates ranging between 0-94.4% (Cryotherapy). The most used Patient-Reported Outcome Measures (PROMs) were the International Prostate Symptom Score and the International Index of Erectile Function for incontinence/urinary function and potency, respectively. The most common reported complications were hematuria, infections, and urethral strictures, with rates widely ranging among different treatments. The Clavien-Dindo Classification was the most used (40/88 papers) to describe adverse events.

CONCLUSION

FT is a promising treatment for localized PCa, achieving excellent results in terms of safety and functional outcomes. There is a wide heterogeneity in the definition of PROMS and time of collection between studies. High quality comparative studies with standard treatments are needed to reinforce these findings.

MRI/real-time ultrasound image fusion guided high-intensity focused ultrasound: a prospective comparative and functional analysis of different ablative techniques

BACKGROUND

The aim of this paper was to compare safety and functional outcomes of total, hemi and focal ablation by the latest focal high-intensity focused ultrasound (HIFU) device.

METHODS

This is a prospective study including patients with low to intermediate-risk PCa treated with HIFU by Focal One^® device from 11/2018 to 3/2020. Before the treatment all patients underwent mp-magnetic resonance imaging (MRI) and subsequent MRI/transrectal ultrasound (TRUS) fusion and standard biopsy. Patients were stratified according to the type of ablation: total, hemi- or focal ablation. Functional data (IPSS, Quality of Life [QoL], IIEF-5, maximum flow [Qmax] and post void residual [PVR] at flowmetry) were assessed preoperatively and at 1, 3, 6 and 12 months after treatment. Moreover, the urinary symptoms reported by patients at IPSS questionnaire were divided in "irritative" and "obstructive" and compared.

RESULTS

One hundred patients were enrolled. Median prostate volume and lesion diameter were 46 (IQR 25-75) mL and 10 (IQR 6-13) mm. 15, 50 and 35 patients underwent total, hemi- and focal ablation, respectively. No differences were found between them except for operative time (lower in the focal group, P<0.01). Significant lower incidence of irritative symptoms was identified in the focal group compared to the others (P<0.05 at 1 and 3 months of follow-up). No differences were found among the baseline status and the postoperative assessment in terms of obstructive IPSS items, IIEF-5, QoL, Qmax and PVR (all P value>0.05).

CONCLUSIONS

Our study suggests that patients' specific HIFU tailoring with the MRI/real-time TRUS Guidance by Focal One^® device is able to minimize the side effects of treatment.

Real-World Comparative Safety and Effectiveness of Irreversible Electroporation and High-Intensity Focused Ultrasound for Prostate Cancer Ablation

OBJECTIVES

To assess the comparative safety and effectiveness of 2 prostate cancer treatment ablation modalities: irreversible electroporation (IRE) and high-intensity focused ultrasound (HIFU).  METHODS: Two systematic literature reviews (SLRs) and meta-analyses (MAs) on IRE and HIFU were conducted in accordance with PRISMA guidelines. Searches were conducted in PubMed and EMBASE. Independent reviewers assessed literature eligibility and abstracted safety and effectiveness data. Oncological, safety, functional, and quality of life (QOL) outcomes were examined for each technology. MAs were conducted where data quality and availability allowed, using normal methods and a random/mixed effects model, and quality assessments performed.

RESULTS

Fifty-five publications (n = 22 IRE; n = 33 HIFU) were included in the SLRs, and MAs were conducted on negative in-field post-procedure biopsy, prostate-specific antigen (PSA) level reduction, potency, urinary continence, and AE rate outcomes. MAs revealed that IRE patients had lower mean percent PSA level reductions, higher mean rates of in-field negative post-treatment biopsy, and higher rates of potency maintenance than HIFU patients. Most adverse events (AEs) reported were comparable and minor (Grades I, II), with urinary tract infection, dysuria, hematuria, and incontinence or urgency most frequently reported. The proportion of patients experiencing a severe AE (≥Grade III) ranged from 0 to 8% after IRE and HIFU. Both modalities were associated with positive functional outcomes as well as maintenance of QOL after treatment.

CONCLUSIONS

Both IRE and HIFU were found to produce favorable effectiveness outcomes and have low complication rates while minimally impacting patient urinary and erectile function and maintaining overall QOL. These real-world findings can help guide clinical decision making and improve disease management for patients with prostate cancer.

Evolving imaging methods of prostate cancer and the emergence of magnetic resonance imaging guided ablation techniques

Established therapies for prostate cancer (PCa), surgery and radiotherapy, treat the entire gland regardless of the location of the cancerous lesion within the prostate. Although effective, these methods include a significant risk of worsening genitourinary outcomes. Targeted image-guided cancer therapy has gained acceptance through improved PCa detection, localization, and characterization by magnetic resonance imaging (MRI). Minimally-invasive ablative techniques aim to achieve comparable oncological outcomes to radical treatment while preserving genitourinary function. Transurethral ultrasound ablation (TULSA) and next-generation transrectal high-intensity focused ultrasound (HIFU) utilize MRI guidance to thermally ablate prostate tissue under real-time MRI monitoring and active temperature feedback control. Previous trials performed by our group and others, including a large multicenter study in men with localized favorable-risk disease, have demonstrated that TULSA provides effective prostate ablation with a favorable safety profile and low impact on quality of life. Recently, MRI-guided HIFU focal therapy was also shown as a safe and effective treatment of intermediate-risk PCa. Here we review the current literature on ablative techniques in the treatment of localized PCa with a focus on TULSA and HIFU methods.

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 therapy of localized prostate cancer

In the treatment of localized prostate cancer, controlling the cancer and maintaining quality of life are important. Focal therapy of localized prostate cancer aims to treat the lesion/part of the prostate that includes the index lesion, which determines the prognosis. We performed a non-systematic review of novel studies on focal therapy of localized prostate cancer as primary treatment published between 2016 and 2021. For mainly intermediate-risk patients, therapeutic technology, such as cryoablation, brachytherapy, high-intensity focused ultrasound, photodynamic therapy, microwave-coagulation, electroporation, and laser ablation, etc., were performed. These procedures are minimally invasive and safe, and provide good functional outcome: a 94-100% pad-free rate against urinary incontinence and 47-86% erectile function, which is sufficient for sexual intercourse. Accurate three-dimensional mapping of the targeted lesion could be an essential navigation technique for therapeutic success. Intermediate- to short-term oncological outcomes were good, resulting in downstaging of the patient's status to no clinically significant cancer; however, transition to conventional whole-gland treatment was necessary in about 10-30% of patients. It is important to select appropriate patients by both multiparametric magnetic resonance imaging and targeted biopsy, and to follow-up postoperatively with methods such as active surveillance. Clinically significant prostate-specific antigen reduction, image response using preoperative and postoperative multiparametric magnetic resonance imaging, and histological analysis should be combined for follow-up.

Evaluation of post-ablation mpMRI as a predictor of residual prostate cancer after focal high intensity focused ultrasound (HIFU) ablation

PURPOSE

To evaluate the performance of multiparametric magnetic resonance imaging (mpMRI) and PSA testing in follow-up after high intensity focused ultrasound (HIFU) focal therapy for localized prostate cancer.

METHODS

A total of 73 men with localized prostate cancer were prospectively enrolled and underwent focal HIFU followed by per-protocol PSA and mpMRI with systematic plus targeted biopsies at 12 months after treatment. We evaluated the association between post-treatment mpMRI and PSA with disease persistence on the post-ablation biopsy. We also assessed post-treatment functional and oncological outcomes.

RESULTS

Median age was 69 years (Interquartile Range (IQR): 66-74) and median PSA was 6.9 ng/dL (IQR: 5.3-9.9). Of 19 men with persistent GG ≥ 2 disease, 58% (11 men) had no visible lesions on MRI. In the 14 men with PIRADS 4 or 5 lesions, 7 (50%) had either no cancer or GG 1 cancer at biopsy. Men with false negative mpMRI findings had higher PSA density (0.16 vs. 0.07 ng/mL², P = 0.01). No change occurred in the mean Sexual Health Inventory for Men (SHIM) survey scores (17.0 at baseline vs. 17.7 post-treatment, P = 0.75) or International Prostate Symptom Score (IPSS) (8.1 at baseline vs. 7.7 at 24 months, P = 0.81) after treatment.

CONCLUSIONS

Persistent GG ≥ 2 cancer may occur after focal HIFU. mpMRI alone without confirmatory biopsy may be insufficient to rule out residual cancer, especially in patients with higher PSA density. Our study also validates previously published studies demonstrating preservation of urinary and sexual function after HIFU treatment.

Focal Therapy for Prostate Cancer: The Impact on Sexual Function

Focal therapy (FT) has emerged as a potential treatment for localized prostate cancer (PCa) with encouraging functional outcomes. According to the compelling evidence based on meta-analyses and recent trials, erectile function (EF) is mostly retained at 6 and 12 months after FT when compared to baseline. These findings are consistent across different energy sources reported to date. However, overall, quality of life, including impotence, was not the endpoint for most studies. Additionally, impotency has not been consistently reported in most of the recent literature. Furthermore, confounding factors such as baseline potency and usage of phosphodiesterase 5 inhibitors (PDE5-I) were also frequently undisclosed. Long-term functional outcomes are awaited. To fully comprehend how FT affects EF, more extensive long-term randomized clinical trials using EF as a primary outcome are needed.

Assessment after focal therapy: what is the latest?

PURPOSE OF REVIEW

To review assessment after focal therapy (FT) in the context of developments from the past two years.

RECENT FINDINGS

With a paucity of high-quality studies, recent findings are primarily reliant on results from institutional-based cohorts and reports of expert consensus. Notably, oncologic treatment failure should be further stratified into recurrence in the in-field or out-of-field ablation zone, and both regions should be surveilled postoperatively. Monitoring primarily consists of periodic evaluations of prostate-specific antigen (PSA) testing and magnetic resonance imaging, with histologic sampling needed to confirm suspicion of recurrence. Recent investigations into PSA derivatives, contrast-enhanced ultrasound, and prostate-specific membrane antigen imaging have shown preliminary promise. Although postablation functional outcomes are generally accepted to be excellent, they are limited by the wide range of patient-reported measures, variability in individual practice, and low questionnaire completion rates.

SUMMARY

There is still a need for high-level, long-term data to inform exact standardized protocols to manage patients after FT. A multifaceted approach is required to surveil patients and identify those at risk of recurrence. Embracing shared responsibility between the patient and clinician to fastidiously monitor the infield and out-of-field ablation zones postoperatively is critical to maximize oncologic outcomes.

Transrectal Ultrasound in Prostate Cancer: Current Utilization, Integration with mpMRI, HIFU and Other Emerging Applications

Transrectal ultrasound (TRUS) has been an invaluable tool in the assessment of prostate size, anatomy and aiding in prostate cancer (PCa) diagnosis for decades. Emerging techniques warrant an investigation into the efficacy of TRUS, how it compares to new techniques, and options to increase the accuracy of prostate cancer diagnosis. Currently, TRUS is used to guide both transrectal and transperineal biopsy approaches with similar cancer detection rates, but lower rates of infection have been reported with the transperineal approach, while lower rates of urinary retention are often reported with the transrectal approach. Multiparametric MRI has substantial benefits for prostate cancer diagnosis and triage such as lesion location, grading, and can be combined with TRUS to perform fusion biopsies targeting specific lesions. Micro-ultrasound generates higher resolution images that traditional ultrasound and has been shown effective at diagnosing PCa, giving it the potential to become a future standard of care. Finally, high-intensity focused ultrasound focal therapy administered via TRUS has been shown to offer safe and effective short-term oncological control for localized disease with low morbidity, and the precise nature makes it a viable option for salvage and repeat 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.

An Updated Systematic Review on Focal Therapy in Localized Prostate Cancer: What Has Changed over the Past 5 Years?

CONTEXT

Focal therapy is a promising, minimally invasive strategy to selectively treat localized prostate cancer. A previous systematic review indicated that there is growing evidence for favorable functional outcomes, but that oncological effectiveness was yet to be defined.

OBJECTIVE

To assess the effectiveness of focal therapy in patients with localized prostate cancer in terms of functional and oncological outcomes.

EVIDENCE ACQUISITION

PubMed, Embase, and The Cochrane Library were searched for studies between October 2015 and December 31, 2020. In addition, the research stages were acquired according to the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) recommendations. Ongoing studies were identified through clinical trial registries.

EVIDENCE SYNTHESIS

Seventy-two studies were identified exploring eight different sources of energy to deliver focal therapy in 5827 patients. Twenty-seven studies reported on high-intensity focused ultrasound (HIFU), nine studies on irreversible electroporation, 11 on cryoablation, eight on focal laser ablation and focal brachytherapy, seven on photodynamic therapy (PDT), two on radiofrequency ablation, and one on prostatic artery embolization. The majority of studies were prospective development stage 2a studies (n = 35). PDT and HIFU, both in stage 3, showed promising results. Overall, HIFU studies reported a median of 95% pad-free patients and a median of 85% patients with no clinically significant cancer (CSC) in the treated area. For PDT, no changes in continence were reported and a median of 90% of patients were without CSC. Both treatments were well tolerated.

CONCLUSIONS

Over the past 5 yr, focal therapy has been studied for eight different energy sources, mostly in single-arm stage 2 studies. Although a first randomized controlled trial in focal therapy has been performed, more high-quality evaluations are needed, preferably via multicenter randomized controlled trials with long-term follow-up and predefined assessment of oncological and functional outcomes and health-related quality-of-life measures.

PATIENT SUMMARY

Focal treatment (FT) of prostate cancer has potential, considering that it has less impact on continence and potency than radical treatment. Our systematic review indicates that despite the method being studied extensively over the past half decade, the majority of studies remain in an early research stage. The techniques high-intensity focused ultrasound and photodynamic therapy have shown most progression toward advanced research stages and show favorable results. However, more high-quality evidence is required before FT can become available as a standard treatment.

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.

Current evidence for focal therapy and partial gland ablation for organ-confined prostate cancer: systematic review of literature published in the last 2 years

PURPOSE OF REVIEW

The shift in the diagnostic algorithm for prostate cancer to early imaging with mpMRI has resulted in many patients being diagnosed with small volume, apparently unilateral, clinically significant cancers. In these patients, a minimally invasive, nonmorbid intervention is appealing. The aim of this study was to review data reported within the last 2 years on focal therapy and partial gland ablation for organ-confined prostate cancer.

RECENT FINDINGS

High-intensity focal ultrasound, focal cryotherapy, photodynamic therapy, irreversible electroporation and focal laser ablation, have been used as treatment modalities for localized prostate cancer treatment. The reported oncologic outcomes vary widely and makes comparisons challenging. All the focal therapies report low rates of complications, and high rates of continence and erectile function preservation. The most common adverse events are hematuria, urinary retention and urinary tract infections. During this period, the initial results of several new technologies including MRI-guided transurethral ultrasound ablation were published.

SUMMARY

Focal therapy and partial gland ablation for organ-confined prostate cancer is an option for patients with intermediate-risk disease because of its low complication profile and preservation of QOL. Trials comparing the outcome of different focal therapy technologies have not been carried out, and the existing evidence does not point to one approach being clearly superior to others. Long-term oncologic outcome is lacking. Despite this, for men with unilateral intermediate-risk prostate cancer whose disease is often relatively indolent, focal therapy is an appealing option.

Imaging of vascular malformations with a high-intensity focused ultrasound probe for treatment planning

OBJECTIVE

We aimed to investigate whether a current commercially available high-intensity focused ultrasound (HIFU) probe can adequately image targeted vascular malformations (VMs) in anticipation of HIFU treatment planning and delivery.

METHODS

We enrolled 10 consecutive patients who were scheduled to undergo treatment of symptomatic peripheral VMs confirmed by routine preoperative contrast-enhanced magnetic resonance imaging and soft tissue duplex ultrasound. The lesions were situated no more than 6 cm from the skin. After induction of general anesthesia and before surgical intervention, we prepared and positioned the Sonablate HIFU probe (SonaCare Medical, LLC, Charlotte, NC) to obtain multiple B-mode images of the targeted VM in the transverse and longitudinal dimensions. We then rated the quality of the images and the feasibility of the imaging process itself using a previously devised questionnaire aimed at evaluating the adequacy of the images for potential HIFU treatment planning and delivery. The patients subsequently underwent surgical intervention and clinical follow-up for their VM per the standard protocol.

RESULTS

The study included 10 participants aged 21 to 67 years (mean ± standard deviation, 36.5 ± 16.5 years). Six patients (60%) identified as female. The VMs imaged consisted of eight venous (80%), one lymphatic (10%), and one combined lymphovenous (10%) malformation. The lesions were in the extremities only (50%), trunk only (20%), trunk and extremities (20%), or neck and extremities (10%). Pain related to the VM was present in all 10 patients (100%). In all 10 patients, the boundary and location of the VM could be visualized via the HIFU probe despite the diminished B-mode imaging resolution. The absence of Doppler functionality in the HIFU probe did not prevent the identification of the VMs in any patient up to a depth of 6 cm. The results from the postimaging survey showed that difficulty in preparing the study device for imaging was 1.1 ± 0.3 and difficulty in use was 1.1 ± 0.1, with a score of 1 equal to easy and 5 to difficult. The stability of the acoustic coupling to the patient was 1.3 ± 0.2, with a score of 1 representing very stable.

CONCLUSIONS

We were able to ultrasonically identify and outline all targeted peripheral VMs using a commercially available HIFU probe in anticipation of treatment planning and delivery. Baseline magnetic resonance imaging and soft tissue duplex ultrasound remain essential tools for guiding probe placement and HIFU imaging.

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.