Focal cryotherapy of localized prostate cancer: a systematic review of the literature

Magnetic resonance imaging-ultrasound fusion guided focal cryoablation for men with intermediate-risk prostate cancer

INTRODUCTION

Focal therapy (FT) is a form of ablative treatment offered to men with localized, organ-confined prostate cancer (CaP). Pelvic multiparametric magnetic resonance imaging (mpMRI) and mpMRI/transrectal ultrasound fusion (MRI-US) guidance enable the precise delivery of FT with limited ablation of adjacent benign tissue or vital genitourinary structures. This article presents our findings on using MRI-US to perform FT as a primary treatment for men with intermediate-risk CaP.

METHODS

Thirty-six men underwent MRI-US fusion-guided FT cryoablation at a single center from 2018 to 2023 as a primary treatment for intermediate-risk CaP. Following FT, quarterly prostate-specific antigen (PSA) testing and a 6 to 9 month mpMRI and combined MRI-US targeted and systematic biopsy were performed. Oncological outcomes were determined using several endpoints containing biochemical recurrence, imaging failure, and pathological failure. Functional outcomes were measured using reported erectile dysfunction/potency rates, urinary incontinence rates, and the American Urologic Association Symptom Score (AUA-SS) and Sexual Health Inventory for Men (SHIM) indices.

RESULTS

Median follow-up was 29.1 months, most (75%) of whom had grade group 2 CaP. Out of the 36 men, 32 (88.9%) completed the combined MRI-targeted and systematic biopsy follow-up after treatment. The study had no major complications, but 12 (33.3%) patients experienced Clavien-Dindo grade II or lower complications. For oncological outcomes, 6 (16.7%) men had biochemical recurrence, 9 (25%) showed imaging failure, and 8 (22.2%) met the criteria for positive biopsy- out-of-field vs. in-field. 88.2% of previously potent patients remained potent postoperatively at 12 months. All patients were continent at 12 months. There were no statistically significant changes in the AUA-SS and SHIM scores postoperatively.

CONCLUSION

MRI-US-guided cryoablation to target lesions in intermediate-risk CaP appears to be a safe treatment option, with functional outcomes indicating minimal short and intermediate-term morbidity and acceptable oncological outcomes. However, despite close monitoring and follow-up, there is still a limitation in accurately predicting/detecting pathological failure after FT. The long-term durability of FT for intermediate-risk, organ-confined CaP remains uncertain.

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.

Focal therapy versus radical prostatectomy and external beam radiotherapy as primary treatment options for non-metastatic prostate cancer: results of a cost-effectiveness analysis

AIMS

Focal therapy treats individual areas of tumour in non-metastatic prostate cancer in patients unsuitable for active surveillance. The aim of this work was to evaluate the cost-effectiveness of focal therapy versus prostatectomy and external beam radiotherapy (EBRT).

MATERIALS AND METHODS

A Markov cohort health state transition model with four health states (stable disease, local recurrence, metastatic disease and death) was created, evaluating costs and utilities over a 10-year time horizon for patients diagnosed with non-metastatic prostate cancer. National Health Service (NHS) for England perspective was used, based on direct healthcare costs. Clinical transition probabilities were derived from prostate cancer registries in patients undergoing radical prostatectomy, EBRT and focal therapy using cryotherapy (Boston Scientific) or high-intensity focused ultrasound (HIFU) (Sonablate). Propensity score matching was used to ensure that at-risk populations were comparable. Variables included age, prostate-specific antigen (PSA), International Society of Urological Pathology (ISUP) grade group, maximum cancer core length (mm), T-stage and year of treatment.

RESULTS

Focal therapy was associated with a lower overall cost and higher quality-adjusted life year (QALY) gains than either prostatectomy or EBRT, dominating both treatment strategies. Positive incremental net monetary benefit (NMB) values confirm focal therapy as cost-effective versus the alternatives at a willingness to pay (WTP) threshold of £30,000/QALY. One-way deterministic sensitivity analyses revealed consistent results.

LIMITATIONS

Data used to calculate the transition probabilities were derived from a limited number of hospitals meaning that other potential treatment options were excluded. Limited data were available on later outcomes and none on quality of life data, therefore, literature-based estimates were used.

CONCLUSIONS

Cost-effectiveness modelling demonstrates use of focal therapy (cryotherapy or HIFU) is associated with greater QALY gains at a lower overall cost than either radical prostatectomy or EBRT, representing good value for money in the NHS.

Prostate minimally invasive procedures: complications and normal vs. abnormal findings on multiparametric magnetic resonance imaging (mpMRI)

Minimally invasive alternatives to traditional prostate surgery are increasingly utilized to treat benign prostatic hyperplasia and localized prostate cancer in select patients. Advantages of these treatments over prostatectomy include lower risk of complication, shorter length of hospital stay, and a more favorable safety profile. Multiparametric magnetic resonance imaging (mpMRI) has become a widely accepted imaging modality for evaluation of the prostate gland and provides both anatomical and functional information. As prostate mpMRI and minimally invasive prostate procedure volumes increase, it is important for radiologists to be familiar with normal post-procedure imaging findings and potential complications. This paper reviews the indications, procedural concepts, common post-procedure imaging findings, and potential complications of prostatic artery embolization, prostatic urethral lift, irreversible electroporation, photodynamic therapy, high-intensity focused ultrasound, focal cryotherapy, and focal laser ablation.

Cryotherapy shows no inferiority compared with radical Prostatectomy for low-risk and intermediate-risk localized Prostate Cancer: a real-world study from the SEER database

Background: For localized prostate cancer (PCa) with a low disease burden, whole-gland resection seems like overtreatment, while focal therapy, including cryosurgery, can achieve similar outcomes. We aimed at comparing the long-term survival outcomes of cryotherapy and radical prostatectomy (RP) and further exploring whether RP can be replaced by cryosurgery for those with low-risk PCa.

Methods: We conducted analyses from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2015) and performed propensity score matching and used an instrumental variate to reduce the influence of bias and unmeasured confounders to the greatest extent.

Results: In the multivariate regression, patients who received cryotherapy had higher risk of overall mortality (OM) (hazard ratio [HR] = 2.52, 95% confidence interval [CI] 1.99-3.20, p < 0.001), but no significant difference was observed in decreasing cancer-specific mortality (CSM) (HR = 1.38, 95% CI 0.63-3.03, p = 0.41) after adjusting the confounders. After propensity score matching, patients who underwent cryotherapy had higher OM and CSM rates (HR = 2.70 [95% CI 1.99-3.66, p < 0.001] and HR = 2.99 [95% CI 1.19-7.48, p = 0.02], respectively). In the IV-adjusted analyses, RP was superior to cryotherapy in decreasing OM (HR = 2.52, 95% CI 1.99-3.20), while no obvious decrease of CSM was observed in the comparison of RP and cryotherapy (HR = 1.38, 95% CI 0.63-3.03). The subgroup analyses showed that RP displayed an obvious benefit in decreasing CSM (HR = 5.02, 95% CI 1.30-19.39, p = 0.02) for those with a prostate-specific antigen (PSA) level higher than 10 ng/ml.

Conclusion: RP ranked as the best treatment in regard to tumor control, but the advantages of cryotherapy became evident when taking functional and oncological outcomes into account, especially for low- and intermediate-risk PCa with low PSA levels.

Whole and hemi-gland cryoablation for primary localized prostate cancer: Short and medium-term oncological and functional outcomes

INTRODUCTION

To compare oncological, functional and post-operative outcomes of hemi (HC) vs. whole gland (WGC) cryoablation as first line treatment of localized prostate cancer.

MATERIAL AND METHOD

Sixty-six consecutive patients undertaking whole-gland cryoablation (WGC=40) or hemi-cryoablation (HC=26) in a tertiary referral centre between 2010 and 2018 were included. All patients had a low-intermediate risk prostate cancer according to D'Amico risk classification. Hemi-ablation was proposed in case of biopsy and prostate MRI proven unilateral prostate cancer. Primary endpoint was Cryotherapy Failure for which 3 definitions were considered and compared: 1) biochemical failure (> PSA nadir+≥ 2 ng/mL), 2) positive prostate re-biopsy with Gleason score ≥ 7, 3) initiation of further prostate cancer treatment.

RESULTS

Median patients age at treatment was 74 [42-81] vs. 76 [71-80] years in WGC vs. HC group, respectively (p=.08). Low and intermediate D'Amico risk group were 15% and 85% vs. 23% and 77% (p=.75), respectively. Median follow- up time was 41 [1.5-99.0] vs. 27 [0.9-93] months (p=.03). Four-years cryotherapy failure free survival in WGC vs. HC were 69% vs. 53% with definition 1 (p=.24), 82% vs. 80% with definition 2 (p=.95), 83% vs. 77% with definition 3 (p=.73). Early and 1-year urinary continence were 60% and 83% in WGC vs. 72% and 83% in HC (p=.26). De novo impotency after cryotherapy was 75% vs. 46% (p=.33) in WGC vs. HC.

CONCLUSIONS

In our cohort of highly selected patients with unilateral low/intermediate risk PCa, hemi-cryoablation may provide similar oncological outcomes and less early complications compared to whole-gland cryoablation.

Focal therapy for localized prostate cancer in the era of routine multi-parametric MRI

BACKGROUND

Prostate cancer focal therapy aims to minimize the side-effects of whole gland treatments, such as radical prostatectomy and radiotherapy without compromising oncological efficacy. However, concerns exist regarding the multifocal nature of prostate cancer and the lack of long-term oncological data for this form of treatment. In recent years, the routine adoption of multi-parametric magnetic resonance imaging (mpMRI) of the prostate has improved our ability to select candidates for focal therapy and to accurately deliver this form of prostate cancer treatment.

METHODS

We performed a review of the literature to provide a summary of the oncological and functional outcomes of men receiving primary prostate focal therapy. Furthermore, we discuss the impact of the routine implementation of mpMRI as part of the initial prostate cancer diagnostic pathway on the selection of candidates and delivery of focal therapy. Finally, we summarize knowledge gaps in the field and highlight active clinical trials in this arena.

RESULTS

Primary focal therapy involves the application of one of a number of energies that ablate tissue, such as cryotherapy and high intensity focused ultrasound (HIFU). Success is principally dependent on highly accurate patient selection and disease localization underpinned in large part by the routine integration of pre-biopsy mpMRI. Prospective medium-term follow-up data for primary HIFU and cryotherapy for men with intermediate-risk disease have shown acceptable cancer control with low risk of side effects and complications. Additional research is needed to clearly define an appropriate follow-up approach and to guide the management of in- and out-of-field recurrences. Multiple comparative trials with randomization against standard care are currently underway in men with intermediate- and high-risk prostate cancer.

CONCLUSION

The widespread adoption of prostate mpMRI has led to improved disease localization, enabling the performance of focal therapy as a viable treatment strategy for men with low volume intermediate-risk prostate cancer.

Anterior gland focal cryoablation: proof-of-concept primary prostate cancer treatment in select men with localized anterior cancers detected by multi-parametric magnetic resonance imaging

Background

Due to their location away from the nerve bundles, anterior prostate cancers (APC) represent a rational target for image-guided cryoablation. This report describes the feasibility and short-term outcomes of anterior focal cryosurgery.

Methods

A retrospective review between 2012 and 2016 of patients with clinically localized APC treated with anterior gland cryoablation was performed. Descriptive statistics were used to report: age, PSA, prostate volume, prostate cancer grade group (PGG), median time to follow-up, and changes in functional status measured with the International Prostate Symptom Score (IPSS) and the International Index of Erectile Function (IIEF-5) score.

Results

A total of 17 patients underwent anterior focal cryoablation with a median follow-up of 15 months. Median age and PSA at diagnosis were 67 years and 8.7 ng/mL. Pre-operative PGG1 was identified in 12 (71%) men and PGG2 in 5 (29%) men. Median (IQR) lesion volume was 2 mL(0.86, 3.1). Preoperative median IIEF-5 and IPSS scores were 19.5 and 5, and decreased to 19 and 4, post-operatively. All patients remained continent with no change in sexual function. All post-procedure targeted biopsies of the treated cancers were negative.

Conclusion

Our pilot study demonstrates the feasibility of treating APCs with image-guided targeted focal cryoablation as a good balance between short-term oncologic control and near complete preservation of genitourinary function. Further follow-up is necessary to examine the potential benefits long-term.

Assessment of Return to Baseline Urinary and Sexual Function Following Primary Focal Cryotherapy for Nonmetastatic Prostate Cancer

BACKGROUND

The oncological outcomes in men with clinically significant prostate cancer following focal cryotherapy are promising, although functional outcomes are under-reported.

OBJECTIVE

To determine the impact of focal cryotherapy on urinary and sexual function, specifically assessing return to baseline function.

DESIGN, SETTING, AND PARTICIPANTS

Between October 2013 and November 2016, 58 of 122 men who underwent focal cryotherapy for predominantly anterior clinically significant localised prostate cancer within a prospective registry returned patient-reported outcome measure questionnaires, which included International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-15) questionnaires.

INTERVENTION

Standard cryotherapy procedure using either the SeedNet or the Visual-ICE cryotherapy system.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcome was return to baseline function of IPSS score and IIEF erectile function (EF) subdomain. Cumulative incidence and Cox-regression analyses were performed.

RESULTS AND LIMITATIONS

Probability of returning to baseline IPSS function was 78% at 12 mo and 87% at both 18 and 24 mo, with recovery seen up to 18 mo. For IIEF (EF domain), the probability of returning to baseline function was 85% at 12 mo and 89% at both 18 and 24 mo, with recovery seen up to 18 mo. Only the preoperative IIEF-EF score was associated with a poor outcome (hazard ratio 0.96, 95% confidence interval 0.93-0.999, p =  0.04). The main limitation was that only half of the patients returned their questionnaires.

CONCLUSIONS

In men undergoing primary focal cryotherapy, there is a high degree of preservation of urinary and erectile function with return to baseline function occurring from 3 mo and continuing up to 18 mo after focal cryotherapy.

PATIENT SUMMARY

In men who underwent focal cryotherapy for prostate cancer, approximately nine in 10 returned to their baseline urinary and sexual function. Keeping in mind that level 1 evidence and long-term data are still needed, in men who wish to preserve urinary and sexual function, focal cryotherapy may be considered an alternative treatment option to radical therapy.

Gold nanoshell-localized photothermal ablation of prostate tumors in a clinical pilot device study

Biocompatible gold nanoparticles designed to absorb light at wavelengths of high tissue transparency have been of particular interest for biomedical applications. The ability of such nanoparticles to convert absorbed near-infrared light to heat and induce highly localized hyperthermia has been shown to be highly effective for photothermal cancer therapy, resulting in cell death and tumor remission in a multitude of preclinical animal models. Here we report the initial results of a clinical trial in which laser-excited gold-silica nanoshells (GSNs) were used in combination with magnetic resonance-ultrasound fusion imaging to focally ablate low-intermediate-grade tumors within the prostate. The overall goal is to provide highly localized regional control of prostate cancer that also results in greatly reduced patient morbidity and improved functional outcomes. This pilot device study reports feasibility and safety data from 16 cases of patients diagnosed with low- or intermediate-risk localized prostate cancer. After GSN infusion and high-precision laser ablation, patients underwent multiparametric MRI of the prostate at 48 to 72 h, followed by postprocedure mpMRI/ultrasound targeted fusion biopsies at 3 and 12 mo, as well as a standard 12-core systematic biopsy at 12 mo. GSN-mediated focal laser ablation was successfully achieved in 94% (15/16) of patients, with no significant difference in International Prostate Symptom Score or Sexual Health Inventory for Men observed after treatment. This treatment protocol appears to be feasible and safe in men with low- or intermediate-risk localized prostate cancer without serious complications or deleterious changes in genitourinary function.

Analyzing the current practice patterns and views among urologists regarding focal therapy for prostate cancer

INTRODUCTION AND OBJECTIVE

Focal therapy (FT) for localized prostate cancer (CaP) has been shown to have encouraging short-term oncological outcomes, excellent preservation of functional outcomes and is increasing in popularity in urologic community. We aim to evaluate the preferences and practice trends among urologists regarding this treatment strategy.

METHODS

A 20 item online questionnaire was designed to collect information on urologists' views and use of FT. The survey was sent to the members of the Endourological Society and the American Urological Association. Multivariate logistic regression analysis was done to determine predictors for utilization of FT.

RESULTS

A total of 425 responses were received [American Urological Association: 319, Endourological Society: 106]. Mean age of respondents was 53(SD: 11.3) years. Although half of the respondents (50.8%) believed FT to be moderate to extremely beneficial in the treatment of CaP, only 24.2% (103) of the respondents currently utilize FT in their practice. Respondents who were fellowship trained in urologic oncology were more likely to consider FT to be at least moderately beneficial (P < 0.001). Surgeon's experience (greater than 15 years in urology practice) (P = 0.025) and seeing more than 10 patients with new CaP diagnosis per month (P = 0.002) were independent predictors of FT utilization for localized CaP. While the most common setting for utilization of FT was in patients with unilateral intermediate-risk (72.8%) CaP, a small percentage of respondents also used FT for patients with unilateral high-risk CaP and bilateral intermediate risk (21.4% and 10.7%, respectively). Most common reasons for not using FT were the lack of belief in 'index lesion theory' (63.2%), lack of experience (41.3%), lack of belief in FT's efficacy (41.1%), lack of infrastructure (35.8%), difficult salvage treatment in cases of recurrence (22.7%) and high cost (21.8%). About 57.6% would use FT more often in an office or outpatient setting if they had access to reliable and cost-effective options.

CONCLUSIONS

Only a quarter of our respondents utilize FT in their practice with surgeon's experience being the important independent predictor for using FT. Majority of respondents though consider FT to be beneficial in CaP management, would use it more often if provided more reliable and cost-effective options. Over time, experience and accessibility to reliable methods to perform FT may lead to further utilization of this novel treatment strategy.

Comparison of T2-Weighted Imaging, DWI, and Dynamic Contrast-Enhanced MRI for Calculation of Prostate Cancer Index Lesion Volume: Correlation With Whole-Mount Pathology

OBJECTIVE

The objective of our study was to investigate the comparative effectiveness of different MRI sequences for the estimation of index lesion volume in patients with prostate cancer (PCa) compared with ground truth volume measured on whole-mount pathology.

MATERIALS AND METHODS

Patients with PCa underwent multiparametric MRI (mpMRI) on a 3-T MRI scanner before radical prostatectomy. Forty PCa index lesions were identified and outlined on histology by a pathologist. Two radiologists who were informed about the presence of PCa but were not aware of lesion outlines on histology worked in consensus to delineate PCa lesions on T2-weighted imaging, apparent diffusion coefficient (ADC) maps, and early-phase dynamic contrast-enhanced MRI (DCE-MRI). The lesion volumes from different mpMRI sequences and the percentage of volume underestimation compared with pathology were calculated and correlated with volume at pathology. The repeated-measures ANOVA with the posthoc Bonferroni test was performed to evaluate whether the difference between the estimated tumor volumes was statistically significant.

RESULTS

The mean PCa lesion volume estimated from pathology, T2-weighted imaging, DWI (ADC maps), and DCE-MRI were 4.61 ± 4.99 (SD) cm³, 2.03 ± 2.96 cm³, 1.81 ± 2.76 cm³, and 3.48 ± 4.06 cm³, respectively. The lesion volumes on T2-weighted images (p = 0.000002), ADC maps (p = 0.000003), and DCE-MR images (p = 0.004412) were significantly lower than those from pathology. PCa lesion volume was significantly underestimated on T2-weighted images, ADC maps, and DCE-MR images compared with pathology by 54.98% ± 22.60% (mean ± SD), 58.59% ± 18.58%, and 18.33% ± 30.11%, respectively; underestimation using T2-weighted imaging (p = 1.01 × 10^-11) and DWI (p = 2.94 × 10^-11) was significantly higher than underestimation using DCE-MRI. Correlations between lesion volume estimated on T2-weighted images, ADC maps, and DCE-MR images with pathology were 0.91 (p = 9.03 × 10^-16), 0.86 (p = 7.32 × 10^-13), and 0.93 (p = 8.22 × 10^-18), respectively.

CONCLUSION

DCE-MRI performed better than T2-weighted imaging and DWI for estimation of index PCa volume and therefore can be preferred over these other two sequences for volume estimation.

Focal Treatment for Unilateral Prostate Cancer Using High-Intensity Focal Ultrasound: A Comprehensive Study of Pooled Data

BACKGROUND

Focal therapy for prostate cancer (PCa) remains experimental. Aim of the current study is to review available evidence and perform a pooled analysis exploring oncologic and functional results of high intensity focus ultrasound (HIFU) focal therapy for the treatment of unilateral PCa.

METHODS

The National Library of Medicine Database was searched for relevant articles. A wide search was performed, including the combination of following words: "HIFU," "prostate," "cancer," and "focal." Overall, 167 articles were reviewed. Of these, seven articles were identified and eligible for the pooled analysis. Data on HIFU hemiablation or focal prostate ablation, oncologic and functional results were pooled from these seven studies that included 366 men with unilateral PCa.

RESULTS

In the 366 analyzed cases, mean age was 67 years (95% confidence interval 66-69), and mean preoperative prostate-specific antigen was 6.4 ng/cc (5.5-7.4). Three studies included PCa up to Gleason 7 (3 + 4), three studies did include also Gleason 7 (4 + 3), whereas one study had no limitation in terms of Gleason score. Regarding early complications, low-grade Clavien-Dindo I-II were reported in 26% (16-37), whereas high-grade Clavien-Dindo ≥III were found in 3.8% (0-8.6). Analyzing oncologic outcomes mean follow-up was 26 months (23-31): at one year after HIFU, negative biopsy rate for clinically significant PCa was 87% (79-96), whereas salvage treatment-free survival rate was 92% (85-98). Regarding functional outcomes, reported potency rates were 74% (64-84), and continence 96% (91-100), although definitions of potency and continence were not homogenous across studies.

CONCLUSIONS

This pooled analysis of the results of focal HIFU treatment of PCa shows promising oncologic and functional outcomes. Well-selected patients may be candidates for such a conservative partial treatment of the gland. Well-designed trials are awaited to compare HIFU focal treatment with current standard of care.

Focal therapy for localized prostate cancer: is there a "middle ground" between active surveillance and definitive treatment?

In recent years, it has come a long way in the diagnosis, treatment, and follow-up of prostate cancer. Beside this, it was argued that definitive treatments could cause overtreatment, particularly in the very low, low, and favorable risk group. When alternative treatment and follow-up methods are being considered for this group of patients, active surveillance is seen as a good alternative for patients with very low and low-risk groups in this era. However, it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active follow-up. In the light of technological developments, the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them yet. According to the initial results, it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate patient. Thus, focal therapies have begun to find their "middle ground" place between definitive therapies and active follow-up.

A Multicentre Study of 5-year Outcomes Following Focal Therapy in Treating Clinically Significant Nonmetastatic Prostate Cancer

Background

Clinically significant nonmetastatic prostate cancer (PCa) is currently treated using whole-gland therapy. This approach is effective but can have urinary, sexual, and rectal side effects.

Objective

To report on 5-yr PCa control following focal high-intensity focused ultrasound (HIFU) therapy to treat individual areas of cancer within the prostate.

Design, setting, and participants

This was a prospective study of 625 consecutive patients with nonmetastatic clinically significant PCa undergoing focal HIFU therapy (Sonablate) in secondary care centres between January 1, 2006 and December 31, 2015. A minimum of 6-mo follow-up was available for599 patients. Intermediate- or high-risk PCa was found in 505 patients (84%).

Intervention

Disease was localised using multiparametric magnetic resonance imaging (mpMRI) combined with targeted and systematic biopsies, or transperineal mapping biopsies. Areas of significant disease were treated. Follow-up included prostate-specific antigen (PSA) measurement, mpMRI, and biopsies.

Outcome measurements and statistical analysis

The primary endpoint, failure-free survival (FFS), was defined as freedom from radical or systemic therapy, metastases, and cancer-specific mortality.

Results and limitations

The median follow-up was 56 mo (interquartile range [IQR] 35–70). The median age was 65 yr (IQR 61–71) and median preoperative PSA was 7.2 ng/ml (IQR 5.2–10.0). FFS was 99% (95% confidence interval [CI] 98–100%) at 1 yr, 92% (95% CI 90–95%) at 3 yr, and 88% (95% 85–91%) at 5 yr. For the whole patient cohort, metastasis-free, cancer-specific, and overall survival at 5 yr was 98% (95% CI 97–99%), 100%, and 99% (95% CI 97–100%), respectively. Among patients who returned validated questionnaires, 241/247 (98%) achieved complete pad-free urinary continence and none required more than 1 pad/d. Limitations include the lack of long-term follow-up.

Conclusions

Focal therapy for select patients with clinically significant nonmetastatic prostate cancer is effective in the medium term and has a low probability of side effects.

Patient summary

In this multicentre study of 625 patients undergoing focal therapy using high-intensity focused ultrasound (HIFU), failure-free survival, metastasis-free survival, cancer-specific survival, and overall survival were 88%, 98%, 100%, and 99%, respectively. Urinary incontinence (any pad use) was 2%. Focal HIFU therapy for patients with clinically significant prostate cancer that has not spread has a low probability of side effects and is effective at 5 yr.

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.

The prostate cancer focal therapy

Despite prostate cancer (PCa) is the leading form of non-cutaneous cancer in men, most patients with PCa die with disease rather than of the disease. Therefore, the risk of overtreatment should be considered by clinicians who have to distinguish between patients with high risk PCa (who would benefit from radical treatment) and patients who may be managed more conservatively, such as through active surveillance or emerging focal therapy (FT). The aim of FT is to eradicate clinically significant disease while protecting key genito-urinary structures and function from injury. While effectiveness studies comparing FT with conventional care options are still lacking, the rationale supporting FT relies on evidence-based advances such as the understanding of the index lesion's central role in the natural history of the PCa and the improvement of multiparametric magnetic resonance imaging (mpMRI) in the detection and risk stratification of PCa. In this literature review, we want to highlight the rationale for FT in PCa management and the current evidence on patient eligibility. Furthermore, we summarize the best imaging modalities to localize the target lesion, describe the current FT techniques in PCa, provide an update on their oncological outcomes and highlight trends for future research.

Management of acquired rectourethral fistulas in adults

Rectourethral fistula is an uncommon but devastating condition resulting from surgery, radiation, trauma, inflammation, or occasionally anorectal anomaly. Because of involving the urinary and the digestive system, surgical repair can be challenging. More than 40 different surgical approaches were described in the literature. However, no standardized management exists due to the rarity and complexity of the problem. Spontaneous closure of fistula is rare and most cases need reconstructive procedures. Appropriate preoperative assessment is crucial for the decision of operation time and method. Gradually accumulating evidence indicates surgeons should take fistula size, tissue health and vascularity associated with radiation or infection, urethral stricture, and bladder neck sclerosis into consideration and make a proper treatment plan according to the features of various approaches. Accurate preoperative evaluation and proper approach selection would increase success rates. Multiple surgical team corporation, including colorectal, urological and plastic surgeons, would optimize the outcomes.

Effects of Focal vs Total Cryotherapy and Minimum Tumor Temperature on Patient-reported Quality of Life Compared With Active Surveillance in Patients With Prostate Cancer

OBJECTIVE

To investigate the effects of focal (hemiablation) or total cryotherapy and minimum tumor temperature on patient-reported quality of life (QoL) in patients with prostate cancer.

METHODS

An Institutional Review Board-approved database was reviewed for patients who underwent cryotherapy or active surveillance (AS). QoL questionnaire responses were collected and scores were analyzed for differences between focal and total cryotherapy and between very cold (<-76°C) and moderate-cold (≥-76°C) minimum tumor temperatures.

RESULTS

A total of 197 patients responded to a total of 547 questionnaires. Focal and total cryotherapy patients had initially lower sexual function scores relative to AS (year 1 mean difference focal: -31.7, P <.001; total: -48.1, P <.001). Focal cryotherapy was associated with a more rapid improvement in sexual function. Both focal and total cryotherapy sexual function scores were not statistically significantly different from the AS cohort by postprocedural year 4. Very cold and moderate-cold temperatures led to initially lower sexual function scores relative to AS (year 1 very cold: -38.1, P <.001; moderate-cold: -30.7, P <.001). Moderate-cold temperature scores improved more rapidly than those of very cold temperature. Neither very cold nor moderate-cold temperatures had a statistically significant difference in sexual function scores relative to AS by postprocedural year 4. Urinary function and bowel habits were not significantly different between focal and total cryotherapy and between very cold and moderate-cold temperature groups.

CONCLUSION

Focal cryotherapy and moderate-cold (≥-76°C) temperature were associated with favorable sexual function relative to total cryotherapy and very cold temperature, respectively. No significant differences in urinary function or bowel habits were observed between groups.

[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.

Use of biological mesh in trans-anal treatment for recurrent recto-urethral fistula

PURPOSE

To report the author's experience on a mini-invasive technique using bioprosthetic plug and a rectal wall flap advancement in the treatment of recurrent recto-urethral fistula.

MATERIALS AND METHODS

Between 2013 and 2015, seven patients with recurrent recto-urethral fistula were referred to the Pederzoli Hospital, Peschiera del Garda, Verona, Italy. Intraoperatively all patients were found to have a rectal wall lesion and were treated with urinary and fecal diversion. For the persistence of the fistula, all the patients underwent a mini-invasive treatment consisting on placement of a bioprosthetic plug in the fistula covered by an endorectal advancement flap through a trans-anal and trans-urethral combined technique.

RESULTS

Median operative time was 48 min with a median blood loss of 30 ml. Median hospital stay was 3 days (IQR 1-3). No case of fistula recurrence or plug migration was described. None of the patients experienced fecal or urinary incontinence. All patients obtained complete fistula healing.

CONCLUSIONS

Recurrent recto-urethral fistula is a challenging postsurgical complication for surgeons and urologists, and its best treatment is still unknown. Our method seems to be feasible and effective for the treatment of complex recto-urethral fistula.

The role of MRI in prostate cancer diagnosis and management

Multiparametric MRI of the prostate demonstrates strong potential to address many limitations of traditional prostate cancer diagnosis and management strategies. Recent evidence supports roles for prostate MRI in prebiopsy risk stratification, guidance of targeted biopsy and preoperative disease staging. Prostate MRI may also assist the planning and follow-up of investigational partial gland ablative therapies. This article reviews the impact of prostate MRI on such diagnostic and therapeutic paradigms in contemporary prostate cancer management.

Emerging minimally invasive procedures for focal treatment of organ-confined prostate cancer

Prostate cancer is the most common malignancy amongst American men. However, the majority of prostate cancer diagnoses are of low risk, organ-confined disease. Many men elect to undergo definitive treatment, but may benefit from focal therapy to maintain continence and potency. This review reports the mechanism of action and outcomes of emerging focal therapies for prostate cancer. We report the mechanism of action of focal cryotherapy, high intensity focused ultrasound, focal laser ablation, and irreversible electroporation. In addition, we reviewed the largest studies available reporting rates of urinary incontinence, erectile dysfunction, biochemical recurrence-free survival (ASTRO), and post-operative adverse events for each procedure. Each treatment modality stated has a unique mechanism in the ablation of cancerous cells. Genito-urinary symptoms following these studies report incontinence and erectile dysfunction rates ranging from 0-15% and 0-53%, respectively. Biochemical disease-free survival was reported using the ASTRO definition. Some treatment modalities lack the necessary follow-up to determine effectiveness in cancer control. No focal therapy studies reported serious adverse events. These minimally invasive procedures are feasible in a clinical setting and show promising functional and disease control results with short to medium-term follow-up. However, each treatment requires additional robust prospective studies as well as its own unique domain to determine biochemical recurrence free survival to properly determine their role in treatment of organ-confined prostate cancer.

Final Results of a Phase I/II Multicenter Trial of WST11 Vascular Targeted Photodynamic Therapy for Hemi-Ablation of the Prostate in Men with Unilateral Low Risk Prostate Cancer Performed in the United States

PURPOSE

Vascular targeted photodynamic therapy with WST11 (TOOKAD® Soluble) is a form of tissue ablation that may be used therapeutically for localized prostate cancer. To study dosing parameters and associated treatment effects we performed a prospective, multicenter, phase I/II trial of WST11 vascular targeted photodynamic therapy of prostate cancer.

MATERIALS AND METHODS

A total of 30 men with unilateral, low volume, Gleason 3 + 3 prostate cancer were enrolled at 5 centers after local institutional review board approval. Light energy, fiber number and WST11 dose were escalated to identify optimal dosing parameters for vascular targeted photodynamic therapy hemi-ablation. Men were treated with photodynamic therapy and evaluated by posttreatment magnetic resonance imaging and biopsy. Prostate specific antigen, light dose index (defined as fiber length/desired treatment volume), toxicity and quality of life parameters were recorded.

RESULTS

After dose escalation 21 men received optimized dosing of 4 mg/kg WST11 at 200 J energy. On posttreatment biopsy residual prostate cancer was found in the treated lobe in 10 men, the untreated lobe in 4 and both lobes in 1. At a light dose index of 1 or greater with optimal dosing in 15 men 73.3% had a negative biopsy in the treated lobe. Six men undergoing retreatment with the optimal dose and a light dose index of 1 or greater had a negative posttreatment biopsy. Minimal effects were observed on urinary and sexual function, and overall quality of life.

CONCLUSIONS

Hemi-ablation of the prostate with WST11 vascular targeted photodynamic therapy was well tolerated and resulted in a negative biopsy in the treated lobe in the majority of men. Dosing parameters and the light dose index appear related to tissue response as determined by magnetic resonance imaging and biopsy. These parameters may serve as the basis for further prospective studies.

Modeling Cryotherapy Ice Ball Dimensions and Isotherms in a Novel Gel-based Model to Determine Optimal Cryo-needle Configurations and Settings for Potential Use in Clinical Practice

Objective

To gain a better understanding of ice ball dimensions and temperature isotherms relevant for cell kill when using combinations of cryo-needles we set out to answer 4 questions: (1) what type of cryo-needle? (2) how many needles? (3) best spatial configuration? and (4) correct duty cycle percentage?

Methods

We conducted laboratory experiments to monitor ice ball dimensions and create multi-needle planar isotherm maps for 17G and 10G cryo-needles using a novel multi-needle thermocouple fixture within gel at body temperature. We tested configurations of 1-4 cryo-needles at duty cycles of 20%-100% with 1-2.5 cm spacing.

Results

Analysis of various combinations shows that a central core of ≤−40°C develops at a distance of ~1 cm around the cryo-needles. Temperature increases linearly from this point to the ice ball leading edge (0°C), which is a further ≈1 cm away. Thus, the −40°C isotherm is approximately 1 cm inside the leading edge of the ice ball.

The optimum distance between cryo-needles was 1.5-2 cm, at duty cycle settings of 70%-100%. At distances further apart or with lower duty cycle settings, ice balls either had a central core >−40°C or had an hourglass shape.

Conclusion

In answer to questions 1-3, tumor length, diameter, and shape will ultimately determine the number of needles and their configuration. However, we propose a conservative distance for cryo-needle placement between 1 and 1.5 cm should be adopted for clinical practice. In answer to question 4, using low duty cycle settings runs the risk of incomplete −40°C isotherm coverage of the tumor, and thus in routine practice we suggest that settings of 70%-100% are most appropriate.

Low temperature plasmas as emerging cancer therapeutics: the state of play and thoughts for the future

The field of plasma medicine has seen substantial advances over the last decade, with applications developed for bacterial sterilisation, wound healing and cancer treatment. Low temperature plasmas (LTPs) are particularly suited for medical purposes since they are operated in the laboratory at atmospheric pressure and room temperature, providing a rich source of reactive oxygen and nitrogen species (RONS). A great deal of research has been conducted into the role of reactive species in both the growth and treatment of cancer, where long-established radio- and chemo-therapies exploit their ability to induce potent cytopathic effects. In addition to producing a plethora of RONS, LTPs can also create strong electroporative fields. From an application perspective, it has been shown that LTPs can be applied precisely to a small target area. On this basis, LTPs have been proposed as a promising future strategy to accurately and effectively control and eradicate tumours. This review aims to evaluate the current state of the literature in the field of plasma oncology and highlight the potential for the use of LTPs in combination therapy. We also present novel data on the effect of LTPs on cancer stem cells, and speculatively outline how LTPs could circumvent treatment resistance encountered with existing therapeutics.

Prostate cancer. Foreword

Professor Hiten Patel is an expert in Laparoscopic and Robotic Surgery for treating prostate disease. He is also a leading researcher in basic science and `clinical research. His basic science research is focused on studying the pathways for improving prostate cancer diagnosis and prognosis through biomarker application, and his clinical research includes new technology applications for training surgeons and improving patient care outcome. Prof Patel is also Chairman of the Urology group for the Enhanced Recovery after Surgery Society.