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

Focal therapy for prostate cancer

Traditional treatments for localized prostate cancer include radical prostatectomy or radiation therapy but pose challenges due to treatment related side effects, namely erectile dysfunction and urinary incontinence. In recent years, focal therapy has emerged as a viable treatment option for localized low-intermediate risk prostate cancer in carefully selected patients. Short and medium-term studies show acceptable cancer control outcomes and reduced morbidity when comparing focal therapy to whole gland treatment for prostate cancer, however there is paucity of long-term studies. Here we review focal ablative therapies commonly used, discuss the role of imaging in monitoring treatment, and summarize oncologic outcomes based on studies to date.

Salvage treatments after focal therapy for prostate cancer - a comprehensive review

OBJECTIVE

To review the literature on salvage treatments after focal therapy (FT) for prostate cancer (PCa).

MATERIALS AND METHODS

A non-systematic literature review was conducted on PubMed, Scopus, and Web of Science up to March 15, 2024, for studies that assessed salvage treatment outcomes in patients with recurrent PCa after primary FT. Original prospective and retrospective studies with more than 10 patients were included. Reviews, editorial comments, conference abstracts, and studies focusing solely on whole-gland treatments were excluded.

RESULTS

Twenty-one studies with a total of 1012 patients were included. The most reported salvage treatments were salvage radical prostatectomy followed by re-do ablation therapy. Only one study evaluated salvage radiation therapy. Except for one prospective study, all studies were retrospective. Oncological outcomes showed acceptable biochemical recurrence rates. Functional outcomes varied, with significant impacts observed on erectile function across modalities, though continence rates were less impacted. Complications were generally low across all treatment options.

CONCLUSION

Salvage treatment post-primary FT is feasible, safe, and has reasonable oncologic outcomes. However, significant declines in sexual function are common, while continence is comparatively less affected. The literature primarily consists of retrospective studies; hence, future research should focus on large-scale prospective evaluations to better define treatment protocols and improve patient outcomes.

The Transatlantic Recommendations for Prostate Gland Evaluation with Magnetic Resonance Imaging After Focal Therapy (TARGET): A Systematic Review and International Consensus Recommendations

BACKGROUND AND OBJECTIVE

Magnetic resonance imaging (MRI) can detect recurrences after focal therapy for prostate cancer but there is no robust guidance regarding its use. Our objective was to produce consensus recommendations on MRI acquisition, interpretation, and reporting after focal therapy.

METHODS

A systematic review was performed in July 2022 to develop consensus statements. A two-round consensus exercise was then performed, with a consensus meeting in January 2023, during which 329 statements were scored by 23 panellists from Europe and North America spanning urology, radiology, and pathology with experience across eight focal therapy modalities. Using RAND Corporation/University of California-Los Angeles methodology, the Transatlantic Recommendations for Prostate Gland Evaluation with MRI after Focal Therapy (TARGET) were based on consensus for statements scored with agreement or disagreement.

KEY FINDINGS AND LIMITATIONS

In total, 73 studies were included in the review. All 20 studies (100%) reporting suspicious imaging features cited focal contrast enhancement as suspicious for cancer recurrence. Of 31 studies reporting MRI assessment criteria, the Prostate Imaging-Reporting and Data System (PI-RADS) score was the scheme used most often (20 studies; 65%), followed by a 5-point Likert score (six studies; 19%). For the consensus exercise, consensus for statements scored with agreement or disagreement increased from 227 of 295 statements (76.9%) in round one to 270 of 329 statements (82.1%) in round two. Key recommendations include performing routine MRI at 12 mo using a multiparametric protocol compliant with PI-RADS version 2.1 standards. PI-RADS category scores for assessing recurrence within the ablation zone should be avoided. An alternative 5-point scoring system is presented that includes a major dynamic contrast enhancement (DCE) sequence and joint minor diffusion-weighted imaging and T2-weighted sequences. For the DCE sequence, focal nodular strong early enhancement was the most suspicious imaging finding. A structured minimum reporting data set and minimum reporting standards for studies detailing MRI data after focal therapy are presented.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The TARGET consensus recommendations may improve MRI acquisition, interpretation, and reporting after focal therapy for prostate cancer and provide minimum standards for study reporting.

PATIENT SUMMARY

Magnetic resonance imaging (MRI) scans can detect recurrent of prostate cancer after focal treatments, but there is a lack of guidance on MRI use for this purpose. We report new expert recommendations that may improve practice.

Comparative Effectiveness of Partial Gland Cryoablation Versus Robotic Radical Prostatectomy for Cancer Control

BACKGROUND AND OBJECTIVE

There is an absence of high-level evidence comparing oncologic endpoints for partial gland ablation, and most series use prostate-specific antigen (PSA) rather than biopsy endpoints. Our aim was to compare oncologic outcomes between partial gland cryoablation (PGC) and radical prostatectomy (RP) for prostate cancer.

METHODS

This was a retrospective, single-center analysis of subjects treated with PGC (n = 98) or RP (n = 536) between January 2017 and December 2022 as primary treatment for intermediate-risk (Gleason grade group [GG] 2-3) prostate cancer. Oncologic endpoints included surveillance biopsies per protocol after PGC in comparison to serial PSA testing after RP. The primary outcome was treatment failure, defined as a need for any salvage treatment or development of metastatic disease. Treatment failure and survival analyses were conducted using Cox proportional-hazard regression and Kaplan Meier survival curves.

KEY FINDINGS AND LIMITATIONS

After applying the inclusion/exclusion criteria, the PGC (n = 75) and RP (n = 298) groups were compared. PGC patients were significantly older (71 vs 64 yr; p < 0.001), but there were no differences in PSA, biopsy GG, or treatment year between the groups. The PGC group had higher rates of treatment failures at 24 mo (33% vs 11%; p < 0.001) and 48 mo (43% vs 14%; p < 0.001). One PGC patient (2.1%) and one RP patient (0.7%) developed metastases by 48-mo follow-up (p = 0.4). On adjusted analysis, PGC was associated with a higher risk of treatment failure (hazard ratio 4.6, 95% confidence interval 2.7-7.9; p < 0.001). Limitations include observational biases associated with the retrospective study design.

CONCLUSIONS

This is the first comparative effectiveness study of cancer control outcomes for PGC versus RP. The results demonstrate an almost fivefold higher risk of treatment failure with PGC during short-term follow-up.

PATIENT SUMMARY

We compared cancer control outcomes for patients with intermediate-risk prostate cancer treated with partial gland cryoablation versus radical prostatectomy. We found that partial gland cryoablation had an almost fivefold higher risk of treatment failure. Men with prostate cancer should be counseled regarding this difference in treatment failure.

MRI-guided Focused Ultrasound Focal Therapy for Intermediate-Risk Prostate Cancer: Final Results from a 2-year Phase II Clinical Trial

Background MRI-guided focal therapy (FT) allows for accurate targeting of localized clinically significant prostate cancer (csPCa) while preserving healthy prostate tissue, but the long-term outcomes of this approach require more study. Purpose To assess the 2-year oncological and functional outcomes of men with intermediate-risk prostate cancer (PCa) treated with targeted FT. Materials and Methods In this single-center prospective phase II trial, men with localized unifocal intermediate-risk PCa underwent transrectal MRI-guided focused ultrasound between July 2016 and July 2019. Planned ablation volumes included 10-mm margins when possible. Data regarding adverse events were collected and quality-of-life questionnaires were completed by participants at 6 weeks and at 5, 12, 18, and 24 months after treatment. Multiparametric MRI and targeted and systematic biopsies were performed at 24 months. Ablation volumes were determined by manual contouring of nonperfused volumes on immediate contrast-enhanced images. Generalized estimating equations were used to model trends in quality-of-life measures. Results Treatment was successfully completed in the 44 participants (median age, 67 years; IQR, 62-70 years; 36 patients with grade group [GG] 2; eight patients with GG 3). No major adverse events from treatment were recorded. One participant refused biopsy at 24 months. After 2 years, 39 of 43 participants (91%) had no csPCa at the treatment site and 36 of 43 (84%) had no cancer in the entire gland. No changes in International Index of Erectile Function-15 score or International Prostate Symptom Score were observed during 2-year follow-up (P = .73 and .39, respectively). Conclusion The majority of men treated with MRI-guided focused ultrasound for intermediate risk PCa had negative results for csPCa at biopsy 2 years after treatment. Additionally, there was no significant decline in quality of life per the validated questionnaires. Clinical trial registration no. NCT02968784 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Woodrum in this issue.

Comparisons of mpMRI, 68Ga-PSMA PET/CT and mpMRI combined with 68Ga-PSMA PET/CT in diagnosing prostate cancer based on tumor detection, localization and staging

PURPOSE

To evaluate the diagnostic ability of mpMRI, 68Ga-PSMA PET/CT and mpMRI combined with 68Ga-PSMA PET/CT in detecting and localizing lesions, and further clarify the accuracy of these examinations in tumor staging.

METHODS

Seventy patients who underwent mpMRI, 68Ga-PSMA PET/CT and radical prostatectomy were enrolled. The abilities to detect index and clinically significant lesions by three examinations were compared. We further evaluated the ability of these examinations to localize lesions to the superior, inferior, anterior, posterior, left and right halves of the prostate and analyzed their accuracy in local and lymph node staging.

RESULTS

There were no significant differences among mpMRI, 68Ga-PSMA PET/CT and mpMRI combined with 68Ga-PSMA PET/CT in their ability to detect index (p = 0.48, p = 0.23 and p = 0.07) and clinically significant lesions (p = 0.30, p = 0.29 and p = 0.06) or to localize lesions in six half divisions of the prostate. With postoperative pathology as reference, both mpMRI (p = 0.10) and mpMRI combined with 68Ga-PSMA PET/CT (p = 0.10) can accurately assess the local staging of prostate cancer. However, 68Ga-PSMA PET/CT underestimates the local staging of prostate cancer (p < 0.01). Regarding lymph node staging, the three types of examination showed no significant differences compared to postoperative pathology (p = 0.63, p = 0.51 and p = 0.14).

CONCLUSIONS

With postoperative pathology as reference, 68Ga-PSMA PET/CT underestimates the local tumor staging. MpMRI combined with 68Ga-PSMA PET/CT has no obvious advantages in detecting, localizing or staging prostate cancer compared with mpMRI.

External validation of biochemical recurrence definition to predict oncologic outcomes following focal therapy for localized prostate cancer using high intensity focused ultrasound

PURPOSE

This is an external validation of several biochemical recurrence definitions based on prostate specific antigen criteria (PSA). The purpose is to predict the need of additional treatment and failure after focal therapy using high intensity focused ultrasound (HIFU) for localized prostate cancer (PCa).

MATERIALS AND METHODS

A total of 343 consecutive patients who underwent HIFU with Ablatherm® and Focal One® devices between June 2001 and November 2020 were identified. Treatment failure was defined as clinically significant PCa on postoperative biopsy, the need for salvage radical or systematic treatment, metastasis, or PCa-related death. The biochemical recurrence definitions tested were PSA nadir, time to PSA nadir, percentage of PSA reduction, Huber et al. criteria defined as PSA nadir + 1 ng/mL at 12 months or PSA nadir + 1.5 ng/mL at 24-36 months. Multivariable Cox regression analysis and decision-curve analysis were used to validate and compare criteria. Kaplan-Meier analysis was used to assess criteria associated with the highest accuracy.

RESULTS

One hundred seventy-eight patients met the inclusion criteria and were analyzed. Overall, 61 (34%) and 41 (23%) patients had an additional treatment and failure with a median follow-up of 52 months. At multivariable analysis, model including Huber et al. criteria exhibited the highest Harrell's C-index for the prediction of the need of additional treatment (hazard ratio [HR]: 10, p < 0.001, c-index: 84%) and treatment failure (HR: 9.1, p < 0.001, c-index: 82%) as well as higher net benefit. The 60-months need of additional treatment and treatment failure-free survival were 89% and 98% compared to 26% and 49%, respectively, when stratified according to Huber et al. criteria (Log-rank test, p < 0.001). Similar results were found after excluding patient with non-clinically significant PCa at initial biopsy.

CONCLUSIONS

We report an external validation of biochemical recurrence definitions predicting the need of additional treatment and failure after focal therapy using HIFU for localized PCa. Huber et al. criteria were identified as the most accurate and could be used to guide clinicians toward further evaluation and salvage treatments.

[Oncological and functional results of focal treatment of localized prostate cancer with HIFU]

INTRODUCTION

In recent years, improved diagnosis of prostate cancer has allowed the development of focal therapy, in order to reduce the morbidity of treatments. Our study assesses the medium-term oncological and functional results of FocalOne® HIFU treatment in localized prostate cancer.

METHODS

This is a retrospective, multicentre study including patients with low- or intermediate-risk localized prostate cancer treated with Focal one HIFU between November 2014 and December 2019. The primary endpoint was the retreatment rate and subgroup analyses were performed to identify predictive factors of retreatment.

RESULTS

One hundred and thirty-seven patients were included with a median follow-up of 25.5 months. Seventy percent of patients had clinical stage T2, 64% had an ISUP score of 2 or 3 on initial biopsies and 38% were treated with hemi-ablation. Follow-up biopsies were performed in 76.6% of patients during follow-up with 21.8% having clinically significant cancers. The retreatment rate at 24 months was 37.2%, with positive biopsies being the primary criterion for retreatment. Patients with a PSA>8ng/mL had a significantly higher retreatment rate. Finally, morbidity remained acceptable with 5.8% of patients requiring reoperation for complications and 21% for de novo erectile dysfunction.

CONCLUSION

Our results are in agreement with those of the literature, seeming to indicate a lower morbidity of the focal treatment by HIFU compared to the radical treatments while offering an acceptable oncological control. Prospective randomized trials are ongoing.

LEVEL OF EVIDENCE: 4

Surveillance one year post focal cryotherapy for clinically significant prostate cancer using mpMRI and PIRADS v2.1: An initial experience from a prospective phase II mandatory biopsy study

Objectives

Multiparametric magnetic resonance imaging (mpMRI) surveillance post focal cryotherapy (FT) of prostate cancer is challenging as post treatment artefacts alter mpMRI findings. In this initial experience, we assessed diagnostic performance of mpMRI in detecting clinically significant prostate cancer (csPCa) after FT.

Materials and methods

This single-centre phase II prospective clinical trial recruited 28 men with localized csPCa for FT between October 2019 and April 2021. 12-months post FT mpMRI were performed prior to biopsy and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of all mpMRI positive subjects were analysed. Chi square goodness of fit test correlated biopsy positive PIRADS3 (P3) and PIRADS4/5 lesions with histology grade group. One way ANOVA test assessed performance of ADC values in differentiating csPCa, non csPCa and benign lesions.

Results

Sensitivity, specificity, PPV and NPV of mpMRI were 100%, 14.28%, 53.84% and 100% for subjects with histologically proven cancer. Correlation of PIRADS v2.1 scores with histologically proven prostate cancer was statistically significant (p < 0.5). Correlation of P3 lesions with non-csPCa was statistically significant (p < 0.02535). Higher ADC value was associated with benign histology (adjusted odds ratio OR 0.97, 95% confidence interval: 0.94, 0.99) (p = 0.008). Among the malignant lesions, higher ADC value was associated with non-csPCa (adjusted OR: 0.97; 95% CI: 0.95, 0.99) (p = 0.032).

Conclusion

mpMRI is highly sensitive in detecting residual cancer. ADC values and PIRADS scores may be of value in differentiating csPCa from non-csPCa with a potential for risk stratification of men requiring re-biopsy versus non-invasive surveillance of remnant prostate.

Impact of 18F-DCFPyL PET/MRI in Selecting Men With Low-/Intermediate-Risk Prostate Cancer for Focal Ablative Therapies

PURPOSE

To compare the diagnostic performance of multiparametric (mp) MRI to 18F-DCFPyL PET/MRI for detecting clinically significant (cs) prostate cancer (PCa) in men with low-/intermediate-risk PCa being considered for focal ablative therapy (FT), using 2 interpretation schemes, and to assess the rate of exclusion from FT for each modality.

METHODS

This prospective study evaluated men with low- or intermediate-risk PCa, potential candidates for FT based on initial biopsy as per institutional protocol, who underwent 18F-DCFPyL PET/MRI. Each modality (mpMRI, PET/MRI using PROMISE classification [PET/MRI PROMISE], and PET/MRI considering any focal lesion on PET as positive [PETFL/MRI]) was assessed independently. All suspicious lesions underwent PET/MRI-ultrasound fusion biopsies. Diagnostic performances were calculated and compared using the exact binomial test on paired proportions.

RESULTS

Thirty-four men (median age, 64 years; interquartile range, 60-70 years) were included. Overall, 40 of 67 lesions (60%) identified on mpMRI and/or PET/MRI were malignant, and 34 of 40 lesions (85%) were csPCa (≥6 mm ISUP [International Society of Urological Pathology Grade Group] GG1 or ISUP-GG ≥2). On lesion-level analysis, for detecting csPCa, sensitivity appeared higher for PETFL/MRI than mpMRI and PET/MRI PROMISE (97% vs 76% and 79%, respectively [P = 0.02 and 0.03]), whereas specificity was lower (30% vs 85% and 88%, respectively [P < 0.001]). The calculated overall accuracy rates for PETFL/MRI, mpMRI, and PET/MRI PROMISE were 64%, 81%, and 84%, respectively. PETFL/MRI, mpMRI, and PET/MRI PROMISE excluded 10 of 34 (29%), 7 of 34 (21%), and 6 of 34 (18%) men from FT, respectively.

CONCLUSIONS

18F-DCFPyL PET/MRI excluded nearly 30% of patients with low-/intermediate-risk PCa from FT, with a potential role in decreasing selection failure. Compared with mpMRI, PET/MRI had a higher sensitivity for detecting csPCa in men who were candidates for FT.ClinicalTrials.gov identifier NCT03149861.

Image-Guided Prostate Cryoablation: State-of-the-Art

Image-guided focal therapy has increased in popularity as a treatment option for patients with primary and locally recurrent prostate cancer. This review will cover the basic indications, evaluation, treatment algorithm, and follow-up for patients undergoing image-guided ablation of the prostate. Additionally, this paper will serve as an overview of some technical approaches to cases so that physicians can familiarize themselves with working in this space. While the focus of this paper is prostate cryoablation, readers will obtain a basic literature overview of some of the additional available image-guided treatment modalities for focal prostate therapy.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Partial-gland Cryoablation Outcomes for Localized Prostate Cancer in Patients with Magnetic Resonance Imaging (MRI)-visible and MRI-invisible Lesions

Background

Expert consensus recommends treatment of magnetic resonance imaging (MRI)-visible prostate cancer (PCa). Outcomes of partial-gland ablation (PGA) for MRI-invisible PCa remain unknown.

Objective

To compare recurrence-free survival, adverse events, and health-related quality of life (HRQoL) outcomes following cryoablation of MRI-visible vs invisible PCa.

Design setting and participants

We analyzed data for 75 men who underwent cryoablation therapy between January 2017 and January 2022. PCa identified on MRI-targeted and/or adjacent systematic biopsy cores was defined as MRI-visible, whereas PCa identified on systematic biopsy beyond the targeted zone was defined as MRI-invisible.

Outcome measurements and statistical analysis

The primary outcome was recurrence at 12 mo after PGA, defined as the presence of clinically significant PCa (grade group [GG] ≥2) on surveillance biopsy. Adverse events were captured using the Clavien-Dindo classification and HRQoL was captured using the Expanded Prostate Cancer Index-Clinical Practice (EPIC-CP) tool.

Results and limitations

Of the 58 men treated for MRI-visible and 17 treated for MRI-invisible lesions, 51 (88%) and 16 (94%), respectively, had at least one surveillance biopsy performed. There were no statistically significant differences in age, race, body mass index, biopsy GG, prostate-specific antigen, prostate volume, or treatment extent between the MRI-visible and MRI-invisible groups. Median follow-up was 44 mo (interquartile range 17-54) and did not significantly differ between the groups. The recurrence rate at 12 mo did not significantly differ between the groups (MRI-visible 39%, MRI-invisible 19%; p = 0.2), and log-rank survival analysis demonstrated no significant difference in recurrence-free survival (p = 0.15). Adverse event rates did not significantly differ (MRI-visible 29%, MRI-invisible 53%; p = 0.092); no man in the MRI-visible group had a Clavien-Dindo grade ≥III complication, while one subject in the MRI-invisible group had a Clavien-Dindo grade III complication. Median EPIC-CP urinary and sexual function scores were similar for the two groups at baseline and at 12 mo after PGA. Study limitations include the retrospective design and small sample size.

Conclusions

We observed similar cancer control, adverse event, and HRQoL outcomes for MRI-visible versus MRI-invisible PCa in the first comparison of partial-gland cryoablation. Longer follow-up and external validation of our findings are needed to inform patient selection for PGA for MRI-invisible PCa.

Patient summary

Patients with prostate cancer lesions that are not visible on magnetic resonance imaging (MRI) scans who undergo partial gland ablation may have similar treatment outcomes compared to patients with cancer lesions that are visible on MRI.

The Association of Tissue Change and Treatment Success During High-intensity Focused Ultrasound Focal Therapy for Prostate Cancer

BACKGROUND

Tissue preservation strategies have been increasingly used for the management of localized prostate cancer. Focal ablation using ultrasound-guided high-intensity focused ultrasound (HIFU) has demonstrated promising short and medium-term oncological outcomes. Advancements in HIFU therapy such as the introduction of tissue change monitoring (TCM) aim to further improve treatment efficacy.

OBJECTIVE

To evaluate the association between intraoperative TCM during HIFU focal therapy for localized prostate cancer and oncological outcomes 12 mo afterward.

DESIGN, SETTING, AND PARTICIPANTS

Seventy consecutive men at a single institution with prostate cancer were prospectively enrolled. Men with prior treatment, metastases, or pelvic radiation were excluded to obtain a final cohort of 55 men.

INTERVENTION

All men underwent HIFU focal therapy followed by magnetic resonance (MR)-fusion biopsy 12 mo later. Tissue change was quantified intraoperatively by measuring the backscatter of ultrasound waves during ablation.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Gleason grade group (GG) ≥2 cancer on postablation biopsy was the primary outcome. Secondary outcomes included GG ≥1 cancer, Prostate Imaging Reporting and Data System (PI-RADS) scores ≥3, and evidence of tissue destruction on post-treatment magnetic resonance imaging (MRI). A Student's t - test analysis was performed to evaluate the mean TCM scores and efficacy of ablation measured by histopathology. Multivariate logistic regression was also performed to identify the odds of residual cancer for each unit increase in the TCM score.

RESULTS AND LIMITATIONS

A lower mean TCM score within the region of the tumor (0.70 vs 0.97, p = 0.02) was associated with the presence of persistent GG ≥2 cancer after HIFU treatment. Adjusting for initial prostate-specific antigen, PI-RADS score, Gleason GG, positive cores, and age, each incremental increase of TCM was associated with an 89% reduction in the odds (odds ratio: 0.11, confidence interval: 0.01-0.97) of having residual GG ≥2 cancer on postablation biopsy. Men with higher mean TCM scores (0.99 vs 0.72, p = 0.02) at the time of treatment were less likely to have abnormal MRI (PI-RADS ≥3) at 12 mo postoperatively. Cases with high TCM scores also had greater tissue destruction measured on MRI and fewer visible lesions on postablation MRI.

CONCLUSIONS

Tissue change measured using TCM values during focal HIFU of the prostate was associated with histopathology and radiological outcomes 12 mo after the procedure.

PATIENT SUMMARY

In this report, we looked at how well ultrasound changes of the prostate during focal high-intensity focused ultrasound (HIFU) therapy for the treatment of prostate cancer predict patient outcomes. We found that greater tissue change measured by the HIFU device was associated with less residual cancer at 1 yr. This tool should be used to ensure optimal ablation of the cancer and may improve focal therapy outcomes in the future.

Time-course changes in multiparametric magnetic resonance imaging following focal cryotherapy for localized prostate cancer: Initial experience

PURPOSE

To evaluate the time-course changes of multiparametric MRI findings following focal cryotherapy for localized prostate cancer.

METHODS

Sixteen patients who underwent focal cryotherapy as an initial curative treatment for localized prostate cancer during March 2017-April 2021 were included. Before the treatment, the patients underwent targeted prostate biopsy using MRI-transrectal ultrasound fusion. Overall, 64 MRIs were conducted after focal cryotherapy and the temporal post-treatment MR signal changes of the ablated area in T2WI, T1WI, DWI, and DCE-MRI were analyzed.

RESULTS

Technical success was achieved in all patients. The median follow-up period was 22 months. The initial post-treatment MRI revealed significant signal changes in the target lesions for all patients, including the disappearance of findings suggestive of cancer. At 3 months post-treatment, most lesions were hyperintense with a hypointense rim on T2WI, T1WI, and DWI (83.3 %). After 6 months, hyperintensity reduced, and after 17 months, all lesions showed hypointensity in these sequences. DCE-MRI of most patients showed loss of internal enhancement; however, one patient exhibited residual nodular enhancement in the ablated area at 3 months, which disappeared after 6 months. Peripheral enhancement was common at 3 months, disappearing after 23 months. Two patients showed biopsy-evidenced local recurrence. The recurrent lesions showed hypointensity on T2WI with diffusion restriction and early contrast enhancement in the ventral transition zone.

CONCLUSION

MRI findings of the ablated sites following focal cryotherapy for localized prostate cancer show dynamic signal changes, especially within the first 6 months.

Cryotherapy for partial gland ablation of prostate cancer: Oncologic and safety outcomes

BACKGROUND

Partial gland ablation (PGA) is a new option for treatment of prostate cancer (PCa). Cryotherapy, an early method of PGA, has had favorable evaluations, but few studies have employed a strict protocol using biopsy endpoints in men with clinically significant prostate cancer (csPCa).

METHODS

143 men with unilateral csPCa were enrolled in a prospective, observational trial of outpatient PGA-cryotherapy. Treatment was a 2-cycle freeze of the affected prostate part. Participants were evaluated with MRI-guided biopsy (MRGB) at baseline and at 6 months and 18 months after treatment. Absence of csPCa upon MRGB was the primary endpoint; quality-of-life at baseline and at 6 months after treatment was assessed by EPIC-CP questionnaires in the domains of urinary and sexual function.

RESULTS

Of the 143 participants, 136 (95%) completed MRGB at 6 months after treatment. In 103/136 (76%), the biopsy revealed no csPCa. Of the 103, 71 subsequently had an 18-month comprehensive biopsy; of the 71 with 18-month biopsies, 46 (65%) were found to have no csPCa. MRI lesions became undetectable in 96/130 (74%); declines in median serum PSA levels (6.9 to 2.5 ng/mL), PSA density (0.15 to 0.07), and prostate volume (42 to 34cc) were observed (all p < 0.01). Neither lesion disappearance on MRI nor PSA decline correlated with biopsy outcome. Urinary function was affected only slightly and sexual function moderately.

CONCLUSION

In the near to intermediate term, partial gland ablation with cryotherapy was found to be a safe and moderately effective treatment of intermediate-risk prostate cancer. Eradication of cancer was better determined by MRI-guided biopsy than by MRI or PSA.

Focal cryotherapy for prostate cancer: a contemporary literature review

Objective

To perform a comprehensive review of the contemporary literature regarding both functional and oncologic outcomes after primary focal cryotherapy for prostate cancer (PCa), providing these results as a foundation for discussing recent developments in the realm of focal therapy.

Background

Traditional treatments for PCa are often associated with debilitating functional side effects for patients. Due to advances in imaging and biopsy strategies, focal ablative therapies recently have garnered much interest and offer an alternative primary treatment for PCa patients with localized disease. Focal cryoablation utilizes heat extraction from tissues to generate an iceball and cause tissue destruction while sparing uninvolved prostatic regions. Optimized patient selection and postoperative management continue to be areas of interest and study as the field continues to develop.

Methods

A search was performed of the PubMed and Embase databases to identify articles pertaining to primary focal PCa cryoablation since our group's last comprehensive review in 2016.

Conclusions

Primary focal cryoablation for PCa offers optimized functional outcomes and a favorable adverse event profile. True evaluation of oncologic outcomes is hampered by lack of long-term follow-up and highly variable clinical endpoints across these studies. Nonetheless, outcomes appear adequate in the short- to medium-term time frame. Utilization of focal cryoablation is expected to grow with continued refinement of patient selection and management options in cases of treatment failure.

Thermal Partial Prostate Ablation for Intermediate- and High-risk Prostate Cancer: Con

Thermal partial-gland ablation (TPGA) is a promising treatment option for patients with prostate cancer (PCa) that has an excellent side-effect profile. However, the literature on TPGA in high-risk PCa is not robust enough to discount the risk of undertreatment and understaging in this population. Future studies, especially with incorporation of advanced imaging to better select patients, are necessary to understand the safety and efficacy of TPGA in high-risk disease.

Guidelines of guidelines: focal therapy for prostate cancer, is it time for consensus?

OBJECTIVE

To provide a summary and discussion of international guidelines, position statements and consensus statements in relation to focal therapy (FT) for prostate cancer (PCa).

METHODS

The European Association of Urology-European Association of Nuclear Medicine-European Society for Radiotherapy and Oncology-European Society of Urogential Radiology-International Society of Urological Pathology-International Society of Geriatric Oncology and American Urological Association-American Society for Radiation Oncology-Society of Urologic Oncology guidelines were interrogated for recommendations for FT. PubMed and Ovid Medline were searched for consensus statements. Only studies in English since 2015 were included. Reference lists of the included articles were also interrogated and a manual search for studies was also performed.

RESULTS

Our results showed a lack of long-term randomised data for FT. International Urological guidelines emphasised the need for more high-quality clinical trials with robust oncological and toxicity outcomes. Consensus and positions statements were heterogenous.

CONCLUSION

A globally accepted guideline for FT planning, technique and follow-up are still yet to be determined. Well-designed studies with long-term follow-up and robust clinical and toxicity endpoints are needed to improve our understanding of FT and create uniform guidelines to streamline management and follow-up.

Topography of Prostate Cancer Recurrence: A Single-centre Analysis of Salvage Radical Prostatectomy Specimens and Implications for Focal Salvage Treatments

Background

Most prostate cancer (PCa) recurrences after nonsurgical first-line treatment are managed with androgen deprivation therapy (ADT). When local treatment is indicated, salvage focal treatment (FT) may achieve outcomes similar to those after salvage radical prostatectomy (sRP), with lower morbidity. However, descriptions of the topography of PCa recurrence are scarce.

Objective

To describe the characteristics and topography of recurrent PCa at sRP.

Design setting and participants

We performed a review of the final pathology for consecutive men undergoing sRP at a single centre between 2007 and 2021.

Outcome measurements and statistical analysis

Clinical and pathological outcomes and recurrence localisation (standardised map) were recorded. Suitability for salvage FT was evaluated using criteria defined a priori.

Results and limitations

We included 41 men who underwent sRP after whole-gland treatment (82.9% primary radiotherapy). Of these, 68.3% had grade group ≥3 and 46.3% had pT3 disease, including nine men (22%) with seminal vesicle involvement >1 cm. The pN+ rate was 29.3%. Surgical margins were positive in 39% (mostly at the apex, 21.9%). PCa was located at <3 mm from the apex in 68% of cases. The segment most frequently involved was the mid-gland (93%). The median prostate and index lesion (IL) volume was 31.4 cm³ (interquartile range [IQR] 23-37) and 2 cm³ (IQR 0.5-6), respectively. A solitary IL was present in 63.4% of cases, while 7.3% had whole-gland PCa involvement. Overall, 56% of the men (n = 23) were deemed suitable for salvage FT (although seven had pN+ disease). The sample size, single-centre retrospective design, and unavailability of magnetic resonance imaging data are the main limitations.

Conclusions

According to sRP pathology, radiorecurrent PCa is an aggressive disease, frequently showing extraprostatic extension, positive margins, and apical involvement. The majority of cases still harbour a solitary index lesion and a consistent proportion may be suitable for a gland-preserving strategy.

Patient summary

In this report we looked at the location of prostate cancer recurrence within the prostate gland after radiotherapy or ablation, in which energy (such as heat, cold, or laser energy) is used to kill cells. We found that although these recurrences are often high-grade locally advanced disease, around half of cases might be suitable for a gland-preserving salvage treatment.

Partial Gland Ablation of Prostate Cancer: Effects of Repeat Treatment

OBJECTIVE

To evaluate the near-term clinical and pathological effects of repeat partial gland ablation (PGA) in men with intermediate-risk prostate cancer (PCa).

MATERIALS AND METHODS

One hundred seventy men with focal lesions of PCa (all GG2 or GG3) underwent PGA with high-intensity focused ultrasound (HIFU) or cryotherapy (CRYO) in prospective trials. Residual PCa in or near the ablation zone was found in 37 men after a first PGA; 30 went on to receive a second PGA and were the subjects of study. At 3 timepoints, baseline and 6 months after first and second ablations, quality-of-life (QOL) questionnaires (IIEF, IPSS) and MRI-guided biopsies (MRGB) were performed. Biopsies were targeted and systematic at baseline and in follow-up, comprehensively about the ablation zone.

RESULTS

All 30 patients completed QOL questionnaires and 26 had MRGB at the 3 timepoints. Mean QOL scores were not significantly different from the baseline after the first or second PGA. No operative complications were encountered; and "decisional regret" was reported in only 2/29 men after the repeat ablation. A decrease in semen volume was reported by 25% of patients. Repeat ablation was successful (absence of csPCa on MRGB) in 14/26 (53%) of men. PSA levels decreased and MRI lesions resolved after ablations, but neither was a reliable predictor of biopsy outcomes.

CONCLUSION

When initial PGA fails, repeat PGA is a reasonable consideration, because in near-term follow-up, secondary procedures appear to be safe, causing only minimal detriment to urinary and sexual function, with csPCa becoming undetectable by MRGB in approximately half the patients.

Prostate Cancer after Percutaneous Arterial Embolization of the Prostate: A Case Report

We report a patient with prostate cancer found 2 years after percutaneous arterial embolization (PAE) of the prostate with a rapid increase in prostate specific antigen (PSA) 3 months later, even though the initial result was low. He did not consult a urologist during or after PAE until acute urinary retention developed. The clinical stage was cT2cN1M1b with Gleason grade 5 + 5 = 10. An increase in PSA a short interval after PAE may suggest the presence of prostate cancer. We suggest that patients undergoing PAE should consult a urologist, and that PSA levels should be checked every 3 months in the first year after PSA.

Impact of prostate biopsy technique on outcomes of the precision prostatectomy procedure

Objective

To assess the impact of iterative changes in preoperative and postoperative biopsy techniques on the outcomes of men undergoing the precision prostatectomy procedure. Precision prostatectomy is a novel surgical treatment for prostate cancer that aims to maximally preserve erectogenic nerves via partial preservation of the prostate capsule.

Design

Retrospective.

Setting

Single tertiary care center.

Participants

This study included 120 patients who consented to undergo prostate cancer treatment with the precision prostatectomy procedure. Patients were originally enrolled in one of two separate prospective protocols studying precision prostatectomy.

Interventions

Preoperatively, 60 patients were screened with transrectal (TR) biopsy and 60 were screened by transperineal (TP) biopsy. Ultimately, 117 patients underwent precision prostatectomy. Of the 43 postoperative biopsies, 19 were TR; 17 were TP with ultrasound; and 7 were TP with microultrasound (mUS).

Main outcome measures

Preoperatively, we evaluated whether the transition to TP biopsy was associated with differences in postoperative treatment failure defined as a neoplasm-positive postoperative biopsy. Postoperative biopsies were compared with respect to their ability to sample the remnant tissue, specifically percentage of cores positive for prostate tissue.

Results

Preoperatively, 9/60 (15%) positive postoperative biopsies occurred in the TR group and 6/60 (10%) in the TP group; Kaplan-Meier survival estimates did not differ between groups (p=0.69 by log rank). Postoperatively, the numbers of cores positive for prostate tissue were 99/160 (62%), 63/107 (59%), and 36/39 (92%) in the TR biopsy, TP with ultrasound, and TP with mUS groups, respectively; this difference was statistically significant versus the rate in the TR and standard TP groups (p=0.0003 and 0.0002).

Conclusion

We found no significant improvement in patient screening, preoperatively—though limited by small sample size and relatively short follow-up. The incorporation of high-frequency mUS for postoperative biopsies improved the ability to sample the remnant tissue with a higher efficiency.

Near-Infrared Photoimmunotherapy (NIR-PIT) in Urologic Cancers

Near-infrared photoimmunotherapy (NIR-PIT) is a novel molecularly-targeted therapy that selectively kills cancer cells by systemically injecting an antibody-photoabsorber conjugate (APC) that binds to cancer cells, followed by the application of NIR light that drives photochemical transformations of the APC. APCs are synthesized by selecting a monoclonal antibody that binds to a receptor on a cancer cell and conjugating it to IRDye700DX silica-phthalocyanine dye. Approximately 24 h after APC administration, NIR light is delivered to the tumor, resulting in nearly-immediate necrotic cell death of cancer cells while causing no harm to normal tissues. In addition, NIR-PIT induces a strong immunologic effect, activating anti-cancer immunity that can be further boosted when combined with either immune checkpoint inhibitors or immune suppressive cell-targeted (e.g., regulatory T cells) NIR-PIT. Currently, a global phase III study of NIR-PIT in recurrent head and neck squamous cell carcinoma is ongoing. The first APC and NIR laser systems were approved for clinical use in September 2020 in Japan. In the near future, the clinical applications of NIR-PIT will expand to other cancers, including urologic cancers. In this review, we provide an overview of NIR-PIT and its possible applications in urologic cancers.

mpMRI-US Fusion-Guided Targeted Cryotherapy in Patients with Primary Localized Prostate Cancer: A Prospective Analysis of Oncological and Functional Outcomes

Simple Summary

Targeted cryotherapy is an emerging treatment for prostate cancer (PCa). mpMRI is a powerful tool for image fusion techniques that deliver incremental precision in diagnostic and treatment of PCa. Fusion targeted cryotherapy (FTC) arises from the simultaneous application of both these procedures. Recurrence is a concern after any type of PCa treatment, especially after targeted treatments. In this article we investigate the recurrence rate after FTC and the role of Prostate-Specific Antigen (PSA) as a predictor of recurrences. Our research provides new evidence on the feasibility of FCT by providing new insights on patient management.

Abstract

Targeted therapy (TT) for prostate cancer (PCa) aims to ablate the malignant lesion with an adequate margin of safety in order to obtain similar oncological outcomes, but with less toxicity than radical treatments. The main aim of this study was to evaluate the recurrence rate (RR) in patients with primary localized PCa undergoing mpMRI/US fusion targeted cryotherapy (FTC). A secondary objective was to evaluate prostate-specific antigen (PSA) as a predictor of recurrences. We designed a prospective single-center single-cohort study. Patients with primary localized PCa, mono or multifocal lesions, PSA ≤ 15 ng/mL, and a Gleason score (GS) ≤ 4 + 3 undergoing FTC were enrolled. RR was chosen as the primary outcome. Recurrence was defined as the presence of clinically significant prostate cancer in the treated areas. PSA values measured at different times were tested as predictors of recurrence. Continuous variables were assessed with the Bayesian t-test and categorical assessments with the chix-squared test. Univariate and logistic regression assessment were used for predictions. A total of 75 cases were included in the study. Ten subjects developed a recurrence (RR: 15.2%), while fifty-six (84.8%) patients showed a recurrence-free status. A %PSA drop of 31.5% during the first 12 months after treatment predicted a recurrence with a sensitivity of 53.8% and a specificity of 79.2%. A PSA drop of 55.3% 12 months after treatment predicted a recurrence with a sensitivity of 91.7% and a specificity of 51.9%. FTC for primary localized PCa seems to be associated with a low but not negligible percentage of recurrences. Serum PSA levels may have a role indicating RR.

Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer: A Systematic Review

Purpose: MRI-guided transurethral ultrasound ablation (TULSA) uses real-time MR thermometry feedback to target prostate disease. We systematically review the literature to synthesize efficacy, functional, and safety outcomes and assess the influence of planned ablation fraction on outcome. Materials and Methods: PubMed, Embase, and the Cochrane Library were searched from inception to June 2021 following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies reporting at least one efficacy, functional, or safety outcome after a single TULSA treatment were included. The relationship of freedom from salvage treatment and potency preservation with planned ablation volume was modeled. Results: Two hundred twenty-four patients were treated in 10 studies with up to a 5-year follow-up, mainly for primary localized prostate cancer (PCa) plus smaller cohorts with recurrent PCa, and locally advanced PCa (LAPC). The prostate-specific antigen decline from baseline up to 2 years, including focal to whole-gland ablation plans, was 54% to 97%. The rate of salvage treatment after one TULSA treatment for primary PCa was 7% to 17%. Continence and potency preservation were from 92% to 100% and from 75% to 98%. Urinary symptoms were stable in men with good voiding function at baseline, and 85% of men with concurrent PCa and lower urinary tract symptoms met the criteria for improvement. Symptom relief in a small cohort of men with LAPC was observed. Grade III adverse events were incurred by 13/224 men (6%), with no rectal injury/fistula or Grade IV complication. The planned ablation fraction was linearly related to salvage-free survival. The relationship between potency preservation and planned ablation fraction followed a sigmoid curve. Conclusions: As an alternative to conventional treatments, TULSA is safe and effective for prostate tissue ablation in men with primary PCa. There is also evidence that TULSA delivers effective relief of urinary symptoms while treating PCa in a single, low-morbidity procedure. The likelihood of freedom from additional treatment or potency preservation is associated with the planned ablation fraction.

Assessment after focal therapy: what is the latest?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current evidence for focal laser ablation and vascular-targeted photodynamic therapy for localized prostate cancer: review of literature published in the last 2 years

PURPOSE OF REVIEW

Currently, a significant number of patients are diagnosed with unilateral and apparently unifocal low or intermediate-risk prostate cancer (PCa). These patients are suitable for focal therapy, thus preventing radical treatment side effects without affecting cancer control. Among focal therapy energy sources, laser-based technologies have shown promising outcomes. We aimed to summarize recent data on focal laser ablation (FLA) and vascular-targeted photodynamic therapy (VTP) for PCa.

RECENT FINDINGS

We selected eight studies reporting data on 1155 patients with PCa who underwent laser-based focal therapy. Five studies were on FLA and three on VTP (six prospective and two retrospective series); four reported both oncologic and functional outcomes whereas in three only oncologic and one only functional outcomes were discussed. Follow-up protocols and durations varied widely among the studies. PCa recurrence rates ranged between 20 and 56%. Urinary and erectile function were preserved after treatment, and complications were mild and transient. A lack of high-quality data on long-term oncological outcomes still remains, thus further highlighting the need for prospective controlled studies.

SUMMARY

FLA and VTP are well tolerated procedures with excellent functional outcomes. However, both procedures showed a significant rate of PCa recurrence, thus demonstrating a certain grade of oncologic control failure of the procedure and/or nonoptimal patients' selection.

Role of multiparametric MRI in long-term surveillance following focal laser ablation of prostate cancer

OBJECTIVE

Determine the multiparametric magnetic resonance imaging (mpMRI) appearance of the prostate following focal laser ablation (FLA) for PCa and to identify imaging characteristics associated with recurrent disease.

METHODS

Retrospective analysis of patients who underwent FLA for low-intermediate risk PCa between 2010 and 2014 was performed. Early (median 4 months) and late mpMRI (median 49 months) follow-up were qualitatively assessed for T₂-weighted, dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) appearances and also compared to corresponding PSA values and biopsy results.

RESULTS

55 cancers were treated in 54 men (mean age 61.0 years). Early mpMRI was performed in 30 (54.5%) patients while late follow-up mpMRI in 42 (84%). Ill-defined scarring with and without atrophy at the treatment site were the most common appearances. In patients with paired MRI and biopsy, one of four patients with clinically significant PCa on biopsy (≥GG2 or≥6 mm GG1) showed hyperenhancement or restricted diffusion at early follow-up. At late follow-up, positive biopsies were seen in 5/8 (63%) cases with hyperenhancement and 5/6 (83%) cases with restricted diffusion at the treatment site. PSA change was not associated with biopsy results at either time point.

CONCLUSION

mpMRI is able to document the morphological and temporal changes following focal therapy. It has limited ability to detect recurrent disease in early months following treatment. Late-term mpMRI is sensitive at identifying patients with recurrent disease. Small sample size is, however, a limitation of the study.

ADVANCES IN KNOWLEDGE

Implementing MRI in follow-up after FT may be useful in predicting residual or recurrent PCa and therefore provide reliable outcome data.

Prevalence and outcomes of focal ablation versus prostatectomy for elderly patients with prostate cancer: a population-based study

Background

Despite rapid advances in the treatment of prostate cancer (PCa), the optimal treatment for elderly patients with PCa remains unclear due to a lack of high-quality evidence. This study aimed to evaluate whether surgical procedures are beneficial for PCa patients aged 75 years and older and compare the effects of focal ablation and prostatectomy.

Methods

Male patients aged 75 years and older who were diagnosed with Tis-T2/N0/M0 PCa between 2000 and 2017 were retrospectively identified from the Surveillance, Epidemiology, and End Results program database. Cox regression models were used to test for statistical differences between the overall survival (OS) and disease-specific survival (DSS).

Results

A total of 114,506 patients aged 75 years and older with PCa were included in this study, among which 60,131 died during the study period. The most prevalent surgical procedure for these patients was focal ablation. The local excision rate increased with advancing age, while the prostatectomy rate decreased sharply with age. The proportion of the elderly patients who underwent a focal ablation also increased with the age at diagnosis. The survival rate of patients aged 75 years and older who underwent a focal ablation was significantly worse than that for those who did not undergo any surgical procedures (OS: HR, 1.32, P<0.001; DSS: HR, 1.58, P<0.001). Although only a few of the patients underwent prostatectomy, the procedure was still related to improved OS and DSS (OS: HR, 0.60, P< 0.001; DSS: HR, 0.37, P<0.001) rates.

Conclusions

Focal ablation has gradually replaced prostatectomy as the most common surgical procedure for elderly patients with PCa in the United States. However, our results revealed that the procedure might not provide benefits for elderly patients with PCa; instead, we found that focal ablation resulted in increased negative effects on patient prognoses. Elderly patients should have the same opportunity to be treated with standard surgical interventions as younger patients.

MR Imaging in Real Time Guiding of Therapies in Prostate Cancer

Magnetic resonance imaging (MRI)-guided therapy for prostate cancer (PCa) aims to reduce the treatment-associated comorbidity of existing radical treatment, including radical prostatectomy and radiotherapy. Although active surveillance has been used as a conservative method to reduce overtreatment, there is a growing demand for less morbidity and personalized (focal) treatment. The development of multiparametric MRI was of real importance in improving the detection, localization and staging of PCa. Moreover, MRI has been useful for lesion targeting within the prostate, as it is used in the guidance of prostate biopsies, by means of cognitive registration, MRI-ultrasound fusion guidance or direct in-bore MRI-guidance. With regard to PCa therapies, MRI is used for precise probe placement into the lesion and to accurately monitor the treatment in real-time. Moreover, advances in MR-compatible thermal ablation allow for noninvasive real-time temperature mapping during treatment. In this review, we present an overview of the current status of MRI-guided therapies in PCa, focusing on cryoablation, focal laser ablation, high intensity focused ultrasound and transurethral ultrasound ablation. We explain the important role of MRI in the evaluation of the completeness of the ablation and during follow-up. Finally, we will discuss the challenges and future development inherent to these new technologies.

Focal therapy for localized prostate cancer - Current status

Focal therapy (FT) has recently gained popularity for the treatment of localized prostate cancer (PCa). FT achieves cancer control by targeting the lesions or the regions of the cancer and avoids damage to the surrounding tissues thus minimizing side effects which are common to the radical treatment, such as urinary continence and sexual function, and bowel-related side effects. Various ablative methods are used to deliver energy to the cancerous tissue. We review the different modalities of treatment and the current state of FT for PCa.

Minimally Invasive Procedures in the Diagnosis and Treatment of Localized Prostate Cancer: an Interventional Radiologist's Perspective

PURPOSE OF REVIEW

Minimal invasive procedures, including targeted biopsy (TB) and focal therapy (FT), are increasingly used in diagnosis and treatment of localized prostate cancer. Here, we review the current role of these procedures, from a perspective of an interventional radiologist.

RECENT FINDINGS

TB is an established part of current guidelines for diagnosis of PCa. Several modalities of FT are gaining prevalence in recent years, as a tissue-preserving alternative for definitive treatment of localized PCa. FT is currently at early research stages, offered to selected patients in clinical trials settings. TB and FT are minimally invasive procedures used by multidisciplinary teams for diagnosis and treatment of localized PCa.

Evolution of Focal Therapy in Prostate Cancer: Past, Present, and Future

Organ sparing approaches for the management of localized prostate cancer were developed in part to overcome the morbidity associated with standard, whole gland treatment options. The first description of focal therapy was now over two decades ago and since that time much has changed. The evolution of patient selection, the approach to ablation, and surveillance after focal therapy have mirrored the technologic advancements in the field as well as the improved understanding of the biology of low-grade, low-risk prostate cancer. This review presents the evidence for the basis of focal therapy from the past to the present and future endeavors.

Future perspective of focal therapy for localized prostate cancer

Objective

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

Methods

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

Results

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

Conclusion

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

Detailing Sexual Outcomes After Focal Therapy for Localised Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Focal therapy has emerged as a promising option to treat well-selected men with localised prostate cancer while preserving healthy prostate tissue and key structures, such as the urethral sphincter and neurovascular bundles. However, how this tissue preservation may translate into improved outcomes, particularly into improved sexual outcomes, is still an active research field.

OBJECTIVE

We conducted a systematic review and meta-analysis of the literature to summarise the existing evidence, in order to provide patients with updated data on what to expect after treatment and help identify gaps in current knowledge that may warrant future research.

EVIDENCE ACQUISITION

A systematic literature search was conducted on Medline, EMBASE, Scopus, and Web of Science. The search strategy was defined using the "litsearchr" function in R based on a preliminary "naïve" search using the following terms on Medline: (("focal therapy" OR "focal treatment") AND ("prostate cancer") AND ("sexual function" OR "erectile function")). A total of 42 studies, comprising 3117 patients treated and 2352 with available sexual outcomes, were included in the qualitative data synthesis and 26 in a random-effect meta-analysis.

EVIDENCE SYNTHESIS

The five-item International Index of Erectile Function (IIEF-5) was the most frequently used questionnaire (30/42 studies), with completion rates ranging from 24% to 100% at 18-24 mo. A decrease was noted at 3 mo (IIEF-5 decrease estimate -3.70 [95% confidence interval -4.43, -2.96]), with improvements at 6 mo (-2.18 [-2.91, -1.46]) and 12 mo (-2.14 [-2.96, -1.32]). Studies in which patients had an altered baseline sexual function were more likely to report a significant and durable postoperative decrease in erectile function scores. The patient-reported outcome questionnaires used were not designed for a diverse population. Functional outcomes were not the primary endpoint and have not been reported consistently in most studies considered.

CONCLUSIONS

Focal therapy led to changes in erectile function in most cases under the significance threshold of the patient-reported outcome questionnaires used. However, patients should be counselled according to their baseline erectile function. More research is warranted to detail aspects other than erectile function, such as ejaculation or orgasm. The early postoperative period appears key to study sexual changes after focal therapy, while only a moderate decrease is expected at 12 mo.

PATIENT SUMMARY

We reviewed the published literature detailing the sexual consequences of focal therapy for localised prostate cancer using patient-reported outcome questionnaires. Patients were likely to describe a significant decrease in their erectile function at 3 mo, with improvements noted at 6 and 12 mo. The results obtained may not be reproducible in a more diverse population, and further research is warranted to better study aspects other than erectile function, such as ejaculation or orgasm.

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.