Focal High-intensity Focussed Ultrasound Partial Gland Ablation for the Treatment of Localised Prostate Cancer: A Report of Medium-term Outcomes From a Single-center in the United Kingdom

Outcomes of Focal Therapy for Localized Prostate Cancer: A Systematic Review and Meta-analysis of Prospective Studies

BACKGROUND AND OBJECTIVE

Focal therapies (FTs) for localized prostate cancer (PCa) are recommended only within prospective registries or clinical trials. In this systematic review and meta-analysis, we aimed to synthesize data from prospective trials evaluating the efficacy and safety of FTs in patients with clinically localized PCa.

METHODS

Systematic searches of the PubMed, Scopus, and Web of Science databases identified prospective studies reporting oncological outcomes of FTs in treatment-naïve, clinically localized PCa patients. The primary endpoint was biopsy-proven clinically significant PCa (csPCa; International Society of Urological Pathology grade group ≥2) recurrence-free survival (csPCa RFS). The secondary endpoints included RFS, radical/systemic treatment-free survival, and adverse event (AE) rates.

KEY FINDINGS AND LIMITATIONS

Fifty studies including 4615 patients treated with FTs were analyzed; of these 50 studies, 19 were on predominantly intermediate-risk (n = 2800), 16 on mixed low-/intermediate-risk (n = 990), and 15 on low-risk (n = 825) patients. Estimates of 12- and 24-mo csPCa RFS rates were 86% (95% confidence interval [CI] 82-89%) and 81% (95% CI: 74-86%), respectively. In the intermediate-risk subgroup, the 12-mo csPCa RFS rate was 79% (95% CI: 74-83%). Five-year radical and systemic treatment-free survival was 82% (95% CI: 75-88%). The pooled incidence of grade ≥3 AEs was 3% (95% CI: 2-5%). Pad-requiring urinary incontinence increased by 3% (95% CI: 0-6%), with 11% of patients developing new erectile dysfunction (95% CI: 4-18%). The median follow-up of 21 mo (interquartile range 12-34) and the use of surrogate endpoints constitute the major limitations.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The primarily short-term data from prospective studies of FT in clinically localized PCa demonstrate moderate to high cancer control with a favorable safety profile.

Single-Port Robotic Transvesical Partial Prostatectomy: A Novel Approach for Focal Treatment in Prostate Cancer

Introduction and Objective: Given the favorable cancer-specific survival rates in localized prostate cancer and the negative impact of whole-gland treatments on functional outcomes, the field is moving toward precision strategies such as focal therapy and organ-sparing surgery. We aim to report medium-term functional and oncologic outcomes for the initial Single-Port Robotic Transvesical Partial Prostatectomy (SP-TVRAPP) patient cohort. Materials and Methods: We analyzed a prospectively maintained database of 20 patients who underwent SP-TVRAPP between February 2021 and March 2024. Inclusion criteria were prostate-specific antigen (PSA) ≤10 ng/mL, clinical stage ≤ cT2b, ISUP Grade Group ≤3, unilateral lesions on multiparametric magnetic resonance imaging (mpMRI) with positive biopsy cores on the same side, and preoperative IIEF-5 ≥ 17. We also considered bilateral prostate cancer in the anterior zone and invisible mpMRI tumors confirmed by unilateral positive biopsies. Results: At baseline, patients had an average age of 61 years, a median PSA of 4.8 ng/mL (interquartile range [IQR]: 3.7-7.7), and a median Sexual Health Inventory for Men (SHIM) score of 24 (IQR: 18-25). All procedures were completed without complications, need for additional ports, or conversion. After a median hospital stay of 4.2 hours, 94% of cases were discharged without opioid prescriptions, and Foley catheters were removed after approximately 4 days. At 6 weeks, 3, 6, and 12 months postprocedure, potency rates, defined as a SHIM score ≥17, were 45.0%, 77.7%, 83.3%, and 87.5%, respectively. When potency was defined as having erections sufficient for penetration, the rates were 80.0%, 88.8%, 88.8%, and 93.7% for the same time intervals. Regarding urinary function, 60.0% were continent at 1 week, increasing to 85.0% by 6 weeks, 88.8% at both 3 and 6 months, and reaching 93.7% at 12 months postsurgery. Oncologically, 30.0% experienced upgrading and 40.0% upstaging within this cohort. Negative surgical margins were attained in 85.0% of the cases and the median PSA was 0.4 ng/mL 12 months after SP-TVRAPP. Two men were found to have residual GG1 cancer in the protocol biopsies and are currently on active surveillance. At a mean follow-up of 15.5 months (0.2-34.8) months, none of the patients has required secondary interventions, and all remain free of both clinically significant residual prostate cancer and metastatic disease. Conclusions: SP-TVRAPP represents a promising treatment for certain patients with localized prostate cancer. This targeted surgical method has been associated with faster postoperative recovery and has demonstrated high rates of early recovery in erectile function and urinary continence while ensuring oncologic safety.

Salvage High-Intensity Focused Ultrasound for Prostate Cancer after Radiation Failure: A Narrative Review

For patients diagnosed with localized prostate cancer, there are multiple treatment options available. The traditional treatment modalities include radical prostatectomy and radiotherapy. Nevertheless, focal therapy, including high-intensity focused ultrasound (HIFU) and cryotherapy, has emerged as a less-invasive method in this setting. Some patients undergoing primary radiation therapy experience recurrence, but there is currently no consensus on the optimal approach for salvage treatment in such cases. The lack of robust data and randomized controlled trials comparing different whole-gland and focal salvage therapies presents a challenge in determining the ideal treatment strategy. This narrative review examines the prospective and retrospective data available on salvage HIFU following radiation therapy. Based on the literature, salvage HIFU for radio-recurrent prostate cancer has promising oncological outcomes, with an overall 5-year survival rate of around 85%, as well as incontinence rates of about 30% based on the patient's risk group, follow-up times, definitions used, and other aspects of the study. Salvage HIFU for prostate cancer proves to be an effective treatment modality for select patients with biochemical recurrence following radiotherapy.

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.

Pilot ex vivo study on non-thermal ablation of human prostate adenocarcinoma tissue using boiling histotripsy

Focused ultrasound technologies are of growing interest for noninvasive ablation of localized prostate cancer (PCa). Here we present the results of the first case study evaluating the feasibility of non-thermal mechanical ablation of human prostate adenocarcinoma tissue using the boiling histotripsy (BH) method on ex vivo tissue. High intensity focused ultrasound field was generated using a 1.5-MHz custom-made transducer with nominal F#=0.75. A sonication protocol of 734 W acoustic power, 10-ms long BH-pulses, 30 pulses per focal spot, 1 % duty cycle, and 1 mm distance between single foci was tested in an ex vivo human prostate tissue sample containing PCa. The protocol used here has been successfully applied in the previous BH studies for mechanical disintegration of ex vivo prostatic human tissue with benign hyperplasia. BH treatment was monitored using B-mode ultrasound. Post-treatment histologic analysis demonstrated BH produced liquefaction of the targeted tissue volume. BH treated benign prostate parenchyma and PCa had similar tissue fractionation into subcellular fragments. The results of the study demonstrated that PCa tumor tissue can be mechanically ablated using the BH method. Further studies will aim on optimizing protocol parameters to accelerate treatment while maintaining complete destruction of the targeted tissue volume into subcellular debris.

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.

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.

Outcomes of partial gland ablation using high intensity focused ultrasound for prostate cancer

BACKGROUND

To evaluate the clinical and oncological outcomes of partial gland ablation (PGA) using high intensity focused ultrasound (HIFU) technique for the clinically unilateral prostate cancer.

METHODS

We performed a retrospective analysis for the 163 patients who treated by PGA for clinically unilateral prostate cancer. The PGA was performed using Focal one system with concurrent trans-urethral prostatectomy. The oncological and functional outcomes were evaluated as well as risk factors for remnant disease after PGA. Clinically significant cancer was defined as grade group ≥2.

RESULTS

Among the entire subjects, grade group 2 or greater was present at pre-treatment biopsy in 76.7%. Median follow-up time was 17 months and 60.1% of total subjects had follow-up biopsy at postoperative 1 year. There were 25 subjects (24.2%) with any cancer and 13 subjects (12.6%) with CS cancer at the follow-up biopsy. The preoperative age and number of positive cores at preoperative biopsy were significantly associated with positive results at follow-up biopsy. Incontinence which requires 2 or more pads per day was observed at 4 subjects (2.5%) postoperatively. There were no subjects who needed intensive care or experienced rectal complications.

CONCLUSION

The PGA with HIFU was safe and showed good preservation of functional outcomes as well as satisfactory oncological control. The remnant disease was observed in the 24.5% of patients who underwent follow-up biopsy in the present study. Thus, further prospective study is needed to evaluate oncological and functional outcomes of PGA with HIFU more accurately.

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.

Available evidence on HIFU for focal treatment of prostate cancer: a systematic review

PURPOSE

Prostate cancer (PCa) is the second most common oncologic disease among men. Radical treatment with curative intent provides good oncological results for PCa survivors, although definitive therapy is associated with significant number of serious side-effects. In modern-era of medicine tissue-sparing techniques, such as focal HIFU, have been proposed for PCa patients in order to provide cancer control equivalent to the standard-of-care procedures while reducing morbidities and complications. The aim of this systematic review was to summarise the available evidence about focal HIFU therapy as a primary treatment for localized PCa.

MATERIAL AND METHODS

We conducted a comprehensive literature review of focal HIFU therapy in the MEDLINE database (PROSPERO: CRD42021235581). Articles published in the English language between 2010 and 2020 with more than 50 patients were included.

RESULTS

Clinically significant in-field recurrence and out-of-field progression were detected to 22% and 29% PCa patients, respectively. Higher ISUP grade group, more positive cores at biopsy and bilateral disease were identified as the main risk factors for disease recurrence. The most common strategy for recurrence management was definitive therapy. Six months after focal HIFU therapy 98% of patients were totally continent and 80% of patients retained sufficient erections for sexual intercourse. The majority of complications presented in the early postoperative period and were classified as low-grade.

CONCLUSIONS

This review highlights that focal HIFU therapy appears to be a safe procedure, while short-term cancer control rate is encouraging. Though, second-line treatment or active surveillance seems to be necessary in a significant number of patients.

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.

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

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

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.

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.

Erectile function after focal therapy for localized prostate cancer: a systematic review

Focal therapy modalities achieved interest in the management of prostate cancer (PCa) over the last a few years. This systematic review was aimed to investigate erectile function after focal therapy for localized PCa. Twenty-six out of 1287 reports were identified through a database systematic search in MEDLINE, EMBASE, and Web of Science, supplemented with hand search, on June 1st, 2020, according to PRISMA guidelines. Focal therapy modalities investigated were cryotherapy, high-intensity focused ultrasound (HIFU), photodynamic therapy (TOOKAD), irreversible electroporation (IRE), and focal radiotherapy (RT) (i.e. brachytherapy or stereotactic RT). Overall, reported sexual function outcomes after these treatment modalities were generally good, with many studies reporting a complete recovery of EF at 1-year follow-up. However, the quality of current evidence is affected both by the lack of well-conducted comparative studies and by a significant heterogeneity in terms of study design, study population, erectile and sexual function assessment modalities.

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.

MR-Guided High-Intensity Directional Ultrasound Ablation of Prostate Cancer

PURPOSE OF REVIEW

The goal of this paper was to review the novel treatment modality of high-intensity transurethral directional ultrasound for prostate cancer.

RECENT FINDINGS

Prostate cancer is a heterogeneous disease with some patients electing for active surveillance and focal therapies instead of definitive treatment with radical prostatectomy or radiation therapy. Prostate MRI has become a cornerstone of prostate cancer diagnosis, targeted biopsy, and treatment planning. Transurethral high-intensity directional ultrasound allows for MRI-guided ablation of the prostate gland with the ability to contour boundaries and spare critical structures, such as the neurovascular bundle and urinary sphincter. Although results are still emerging, this may offer patients a new option for focal therapy with a favorable side-effect profile. High-intensity transurethral directional ultrasound is an emerging treatment modality for both whole-gland and focal ablation with promising early results. Further research is needed to establish safety, tolerability, and long-term oncologic outcomes.

A systematic review of irreversible electroporation in localised prostate cancer treatment

Irreversible electroporation is a treatment option used for focal therapy. In this systematic review, we summarise data on irreversible electroporation outcomes in patients with localised prostate cancer. We performed a literature search in 3 databases and included articles with own data on irreversible electroporation results in patients with localised prostate cancer. Primary outcome was procedure efficacy measured as the absence of cancer in the treatment area on the follow-up biopsy. Secondary outcomes were the absence of prostate cancer recurrence in the treatment area on MRI, out-of-field recurrence, complications and functional outcomes (erectile function and micturition). In-field recurrence rate was 0%-39% and out-field 6.4%-24%. In all studies, PSA level decreased: twice lower than baseline after 4 weeks and by 76% after 2 years. Most of the authors noted sexual and urinary toxicity during the first half year after surgery. However, functional outcomes recovered to baseline after 6 months with mild decrease in sexual function. Complication rates after irreversible electroporation were 0%-1% of Clavien-Dindo III and 5%-20% of Clavien-Dindo I-II. Irreversible electroporation has promise oncological outcomes, rate of post-operative complications and minimal-to-no effects on erectile and urinary function. However, medium and long-term data on cancer-specific and recurrence-free survival are still lacking.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Standardized Nomenclature and Surveillance Methodologies After Focal Therapy and Partial Gland Ablation for Localized Prostate Cancer: An International Multidisciplinary Consensus

BACKGROUND

Focal therapy (FT) and partial gland ablation (PGA) are quickly adopted by urologists and radiologists as an option for the management of localized prostate cancer.

OBJECTIVE

To find consensus on a standardized nomenclature and to define a follow-up guideline after FT and PGA for localized prostate cancer in clinical practice.

DESIGN, SETTING, AND PARTICIPANTS

A review of the literature identified controversial topics in the field of FT. Online questionnaires were distributed to experts during three rounds, with the goal to achieve consensus on debated topics. The consensus project was concluded with a face-to-face meeting in which final conclusions were formulated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Controlled feedback of responses of previous rounds were summarized and returned to the participants allowing them to re-evaluate their decisions. The level of agreement to achieve consensus on a topic was set at 80%.

RESULTS AND LIMITATIONS

Sixty-five experts participated in this interdisciplinary consensus study (72% urologists; 28% radiologists). The experts propose the use of the herein standardized nomenclature for ablative procedures. After FT/PGA, the following tests should be performed to assess treatment outcomes: prostate-specific antigen (PSA), imaging, biopsies, and functional outcome assessment. Although not a reliable marker for treatment failure, PSA should be measured every 3 mo in the 1st year and every 6 mo thereafter. Magnetic resonance imaging is the preferred image modality and should be performed at 6 and 18 mo after treatment. A systematic 12-core transrectal ultrasound-guided biopsy combined with a targeted biopsy of the treated area should be performed 6-12 mo after treatment. Functional outcomes should be obtained 3-6 mo after treatment for the first time and until stability is attained.

CONCLUSIONS

The panel recommends the use of the proposed nomenclature and follow-up protocols to generate reliable data supporting a broader implementation of FT as a standard of care for select patients with localized prostate cancer.

PATIENT SUMMARY

In this report, we present expert opinion on the use of a standardized nomenclature, and surveillance methodologies after focal therapy and partial gland ablation for localized prostate cancer.

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.

Current state of image-guided focal therapy for prostate cancer

PURPOSE

To review the current evidence regarding protocols and outcomes of image-guided focal therapy (FT) for prostate cancer (PCa).

METHODS

A literature search of the latest published studies assessing primary FT for PCa was carried out in Medline and Cochrane library databases followed by a critical review. FT modalities, follow-up strategies, and oncological and toxicity outcomes were summarized and discussed in this review.

RESULTS

Twenty-four studies with six different sources of energy met the inclusion criteria. A heterogeneity of patient selection, energy sources, treatment templates, and definitions of failure was found among the studies. While a third of patients may be found to have additional cancer burden over 3-5 years following FT, most patients will remain free of a radical procedure. The vast majority of patients maintain urinary continence and good erectile function after FT. Acute urinary retention is the most common complication, whilst severe complications remain rare.

CONCLUSION

An increasing number of prospective studies with longer follow-up have been recently published. Acceptable cancer control and low treatment toxicity after FT have been consistently reported. Follow-up imaging and routine biopsy must be encouraged post-FT. While there is no reliable PSA threshold to predict failure after FT, reporting post-FT positive biopsies and retreatment rates appear to be standard when assessing treatment efficacy.

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.