A systematic review of salvage focal therapies for localised non-metastatic radiorecurrent prostate cancer

Salvage high-intensity focused ultrasound (S-HIFU) for recurrence after primary radiotherapy of prostate cancer

OBJECTIVES

To evaluate functional and oncological outcomes of salvage high-intensity focal ultrasound (S-HIFU) after external beam radiotherapy (EBRT) failure in prostate cancer (PCa) patients.

METHODS

This single-center study included patients who underwent S-HIFU for local recurrence after EBRT between 2006 and 2023. Cancer-specific survival, metastasis-free survival and progression-free survival were illustrated using Kaplan-Meier curves. Disease progression was defined by one of the following criteria: increase of 2ng/mL or more above the PSA nadir, positive post-S-HIFU biopsy or initiation of androgen deprivation therapy (ADT). Multivariable Cox proportional hazards model was used to identify predictors of disease progression after S-HIFU.

RESULTS

A total of 52 S-HIFU sessions for 48 patients were performed. Median time between EBRT and S-HIFU was 6.5 years. Median PSA before S-HIFU was 3.2ng/mL and median PSA nadir after S-HIFU was 0.58ng/mL. A total of 39 (81.3%) complications was recorded, including 3 (6.3%) high grade complications according to the Clavien-Dindo classification. After a median follow-up period of 6 years, 14 (29.2%) patients developed metastatic disease. Eighteen (37.5%) patients had no recurrence, whereas 30 (62.5%) patients received ADT for disease progression. The estimated 5-yr cancer-specific survival (CSS), metastasis-free survival (MFS) and progression-free survival rates (PFSR) were 100%, 79.9% (95% CI 67-92) and 41.2% (95% CI 74-96), respectively. The estimated 10-yr CSS, MFS and PFSR were 80% (95% CI 45-100), 50.7% (95% CI 19.4-82.1) and 14% (95% CI 10.8-45), respectively. The hazard of progression increased with the intermediate (HR 3.8; 95% CI 0.99 to 15; p=0.049) and high pre-EBRT d'Amico-s risk group (HR 4.1; 95% CI 0.98 to 16.2; p=0.050). Also, the time between EBRT and S-HIFU was significantly associated with risk of progression (HR 0.61; 95% CI 0.43 to 0.86; p=0.004). No significant difference linked to the disease progression (DP) risk was found between focal vs whole-gland treatment (p=0.70).

CONCLUSION

Physicians should consider HIFU as a local salvage treatment after failed EBRT, thus avoiding or delaying palliative androgen deprivation therapy. Further studies are needed to improve patient selection for this therapy.

LEVEL OF EVIDENCE: 4

Evaluation of Recurrent Disease after Radiation Therapy for Patients Considering Local Salvage Therapy: Past vs. Contemporary Management

Recurrent prostate cancer after primary treatment with radiation therapy is a common problem. Patients with localized recurrence may benefit from salvage therapy, but careful patient selection is crucial because not all patients will benefit from local salvage therapy, and salvage therapy has increased morbidity compared to primary treatments for prostate cancer. This review aims to provide an overview of the evaluation of patients with recurrent disease after radiation therapy and how it is continuing to evolve with increasing data on outcomes, as well as improving technologies and techniques. Our enhanced understanding of treatment outcomes and risk stratification has influenced the identification of patients who may benefit from local salvage treatment. Advances in imaging and biopsy techniques have enhanced the accuracy of locating the recurrence, which affects treatment decisions. Additionally, the growing interest in image-targeted ablative therapies that have less morbidity and complications than whole-gland therapies for suitable patients influences the evaluation process for those considering focal salvage therapy. Although significant changes have been made in the diagnostic evaluation of patients with recurrent disease after radiation therapy, it remains unclear whether these changes will ultimately improve patient outcomes.

Ultrasound targeted microbubble destruction using docetaxel and Rose Bengal loaded Microbubbles for targeted Chemo-Sonodynamic therapy treatment of prostate cancer

Docetaxel (DTX) chemotherapy is commonly used in the treatment of patients with advanced prostate cancer demonstrating modest improvements in survival. As these patients are often elderly and the chemotherapy treatment is not targeted, it is often poorly tolerated. More targeted approaches that increase therapeutic efficacy yet reduce the amount of toxic chemotherapy administered are needed. In this manuscript, we investigate the potential of ultrasound targeted microbubble destruction (UTMD) to deliver a combination of docetaxel chemotherapy and Rose Bengal mediated sonodynamic therapy (SDT) in pre-clinical prostate cancer models. A Rose Bengal modified phospholipid was synthesized and used as a component lipid to prepare a microbubble (MB) formulation that was also loaded with DTX. The DTX-MB-RB formulation was used in the UTMD mediated treatment of androgen sensitive and androgen resistant 3D spheroid and murine models of prostate cancer. Results from the 3D spheroid experiments showed UTMD mediated DTX-MB-RB chemo-sonodynamic therapy to be significantly more effective at reducing cell viability than UTMD mediated DTX or SDT treatment alone. In an androgen sensitive murine model of prostate cancer, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was as effective as androgen deprivation therapy (ADT) at controlling tumour growth. However, when both treatments were combined, a significant improvement in tumour growth delay was observed. In an androgen resistant murine model, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was significantly more effective than standard DTX monotherapy. Indeed, the DTX dose administered using the DTX-MB-RB formulation was 91% less than standard DTX monotherapy. As a result, UTMD mediated DTX-MB-RB treatment was well tolerated while animals treated with DTX monotherapy displayed significant weight loss which was attributed to acute toxic effects. These results highlight the potential of UTMD mediated DTX-MB-RB chemo-sonodynamic therapy as a targeted, well tolerated alternative treatment for advanced prostate cancer.

External validation of a risk model predicting failure of salvage focal ablation for prostate cancer

OBJECTIVES

To externally validate a published model predicting failure within 2 years after salvage focal ablation in men with localised radiorecurrent prostate cancer using a prospective, UK multicentre dataset.

PATIENTS AND METHODS

Patients with biopsy-confirmed ≤T3bN0M0 cancer after previous external beam radiotherapy or brachytherapy were included from the FOcal RECurrent Assessment and Salvage Treatment (FORECAST) trial (NCT01883128; 2014-2018; six centres), and from the high-intensity focussed ultrasound (HIFU) Evaluation and Assessment of Treatment (HEAT) and International Cryotherapy Evaluation (ICE) UK-based registries (2006-2022; nine centres). Eligible patients underwent either salvage focal HIFU or cryotherapy, with the choice based predominantly on anatomical factors. Per the original multivariable Cox regression model, the predicted outcome was a composite failure outcome. Model performance was assessed at 2 years post-salvage with discrimination (concordance index [C-index]), calibration (calibration curve and slope), and decision curve analysis. For the latter, two clinically-reasonable risk threshold ranges of 0.14-0.52 and 0.26-0.36 were considered, corresponding to previously published pooled 2-year recurrence-free survival rates for salvage local treatments.

RESULTS

A total of 168 patients were included, of whom 84/168 (50%) experienced the primary outcome in all follow-ups, and 72/168 (43%) within 2 years. The C-index was 0.65 (95% confidence interval 0.58-0.71). On graphical inspection, there was close agreement between predicted and observed failure. The calibration slope was 1.01. In decision curve analysis, there was incremental net benefit vs a 'treat all' strategy at risk thresholds of ≥0.23. The net benefit was therefore higher across the majority of the 0.14-0.52 risk threshold range, and all of the 0.26-0.36 range.

CONCLUSION

In external validation using prospective, multicentre data, this model demonstrated modest discrimination but good calibration and clinical utility for predicting failure of salvage focal ablation within 2 years. This model could be reasonably used to improve selection of appropriate treatment candidates for salvage focal ablation, and its use should be considered when discussing salvage options with patients. Further validation in larger, international cohorts with longer follow-up is recommended.

MRI-Guided Salvage Focal Cryoablation: A 10-Year Single-Center Experience in 114 Patients with Localized Recurrent Prostate Cancer

Patients with localized recurrent prostate cancer (PCa) are eligible for androgen-deprivation therapy, salvage radical prostatectomy (RP) or radiation therapy. These treatments are associated with serious side-effects, illustrating the need for alternative local treatment options with lower morbidity rates. All patients who underwent magnetic resonance imaging (MRI)-guided salvage focal cryoablation (SFC) with localized recurrent PCa between 2011-2021 (n = 114) were included. Two subgroups were formed: patients without (n = 99) and with prior RP (n = 15). We assessed the recurrence- (RFS) and treatment-free survival (TFS), measured from date of treatment to date of recurrence or initiation of additional salvage treatment, using Kaplan-Meier plots. Complications were reported using the Clavien-Dindo (CD) scale. Overall 1-year and 5-year RFS were 76.0% and 25.1%, and overall 1-year and 5-year TFS were 91.5% and 58.2%, respectively. Patients without prior RP showed a significantly higher 1-year (78.5% vs. 52.5%) and 5-year RFS (28.1% vs. 0.0%; p = 0.03), and a trend towards a higher 1-year (92.6% vs. 79.0%) and 5-year TFS (60.2% vs. 23.0%; p = 0.10) compared to those with prior RP. A total of 46 complications occurred in 37 patients, and the overall complication rate was 32.4% (37/114 patients). The majority (41/46; 89.1%) of complications were minor (CD 1-2). Overall (31.3 vs. 40.0%) and major (3.0 vs. 13.3%) complication rates were lower in patients without compared to those with prior RP, respectively. MRI-guided SFC is an effective and safe therapy for patients with recurrent PCa, and has proved to delay and potentially prevent the initiation of salvage treatments. Patients with locally recurrent PCa after prior RP had an increased risk of recurrence, a shortened time to additional treatment, and more complications compared to those without prior RP, which should be considered when selecting patients for SFC.

Recurrence characteristics after focal salvage HDR brachytherapy in prostate cancer

BACKGROUND AND PURPOSE

Radiorecurrent prostate cancer is often confined to the prostate, predominantly near the index lesion. The purpose of this study was to look at recurrence characteristics in patients treated with focal salvage high dose-rate (HDR) brachytherapy.

MATERIALS AND METHODS

Patients treated with MRI-guided HDR brachytherapy, with a single fraction of 19 Gy from July 2013 to October 2021 as focal salvage treatment, were prospectively included in the current study. Imaging data were collected regarding the occurrence of local, regional and distant recurrences, including location of local recurrences (LR) in relation to the HDR radiotherapy field.

RESULTS

One hundred seventy-five patients were included after focal salvage HDR brachytherapy (median follow-up 36 months (IQR 23-50)). Three-years biochemical recurrence-free survival, LR-free survival, in-field LR-free survival, out-of-field LR-free survival, any-recurrence-free survival and ADT-free survival were 43% (95%CI 34%-52%), 51% (41%-61%), 70% (61%-80%), 92% (88%-97%), 42% (32%-52%) and 86% (80%-92%), respectively. Larger GTV-size and shorter PSA doubling time were associated with in-field LR in multivariable analysis.

CONCLUSION

After focal salvage HDR brachytherapy with a dose of 1x19 Gy for local prostate cancer recurrence, subsequent recurrences are mostly local and in-field.

Narrative review-focal therapy: are we ready to change the prostate cancer treatment paradigm?

Background and Objective

Prostate cancer (PCa) has seen improved detection methods with a subsequent rise in disease prevalence, making novel prostate cancer treatment options an exciting yet controversial topic. Current treatment modalities encompass traditional approaches, namely surgery (radical prostatectomy) and radiation therapy. While heralded as a standard of care, these modalities may come with significant risk profiles, primarily sexual (erectile dysfunction) and urinary incontinence. Advances in technology and imaging, specifically multi-parametric MRI, have afforded great leaps in targeted focal therapy as a primary treatment option for localized PCa. This review identifies and highlights published data for novel and emerging PCa focal therapy (FT) modalities.

Methods

Our study identified and reviewed the current literature for relevant investigations related to primary FT modalities as they apply to the treatment of prostate cancer. After an internal review, relevant studies (published in English, between 2000-April 2022) were included for analysis and summarization.

Key Content and Findings

We provide a concise review of several novel focal therapy modalities that offer realistic potential for primary treatment of localized prostate cancer. Our narrative includes studies that primarily include their respective results, specifically focusing on those that reported both oncologic and quality-of-life outcomes after focal therapy. While still in its cumulative infancy, we discuss the current limitations, future directions, and advancements that hopefully push focal therapy into the limelight.

Conclusions

While many of the mentioned focal therapies for PCa have shown promising pathologic and quality of life outcomes, further clinical evidence is required to change overall management guidelines and recommendations. The advantages of FT in avoiding sexual and urinary side-effects of radical surgery or radiation are apparent; however, it is necessary to recognize the need for further long-term evidence that is durable over time and comparable to current gold-standard treatment options.

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.

The SAFE Pilot Trial—SAlvage Focal Irreversible Electroporation—For Recurrent Localized Prostate Cancer: Rationale and Study Protocol

Introduction

Currently, the majority of prostate cancer (PCa) recurrences after non-surgical first-line treatment are managed with androgen-deprivation therapy (ADT). Salvage radical prostatectomy (sRP) is a curative alternative to ADT but yields significant morbidity. Preliminary evidence from focal salvage treatments shows similar oncological control but lower morbidity compared to sRP. Among available ablative focal energies, irreversible electroporation (IRE) is a treatment modality that proved promising, especially in treating apical lesions, where PCa most often recurs. Our aim is to test the safety of salvage IRE for recurrent PCa.

Methods

We performed a single-arm pilot feasibility study (IDEAL stage 2a): SAFE, SAlvage Focal irreversible Electroporation for recurrent localized PCa. Twenty patients with biopsy-proven PCa recurrence after primary non-surgical (radiation or ablation) treatment were included. All men will undergo mpMRI ± targeted biopsies, pre-operative PSMA-PET staging before inclusion and sIRE. Outcomes will be evaluated through internationally validated questionnaires and morbidity scales. All men will undergo a control biopsy at one year.

Results

Primary objectives were the evaluation of the safety of sIRE (and patients’ quality of life) after treatment. Secondary objectives were the evaluation of functional outcomes, namely, continence and erectile function changes and evaluation of short-term oncological efficacy.

Conclusions

SAFE is the second pilot study to evaluate sIRE and the first one performed according to the most recent diagnostic and staging imaging standards. sIRE may provide a curative option for recurrent PCa together with lower comorbidities compared to sRP.

Clinical and pathologic characteristics to select patients for focal therapy or partial gland ablation of nonmetastatic prostate cancer

PURPOSE OF REVIEW

Focal therapy or partial gland ablation for nonmetastatic prostate cancer is gaining popularity not just as an alternative to active surveillance, but as an acceptable alternative to whole gland therapy in appropriate cases. This review summarizes recent evidence to help select patients for optimal outcomes.

RECENT FINDINGS

Recommendations by expert panels have become less conservative with each meeting. As experience with older modalities for focal therapy grows, newer modalities continue to be introduced. We are now in a position to offer personalized treatment pathway considering nuances of each focal therapy modality.

SUMMARY

The ideal case for focal therapy should be an MRI visible significant lesion (PIRADS score ≥ 3), with a positive biopsy for significant cancer (Gleason grade group 2-3) in the corresponding targeted biopsy area, and insignificant or absent disease in the nontarget random biopsy areas. Multifocal disease can also be selectively treated. Salvage focal ablation is an attractive treatment option for radio-recurrent or index focal therapy failure cases.

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.

Defining radio-recurrent intra-prostatic target volumes using PSMA-targeted PET/CT and multi-parametric MRI

Purpose

Our purpose was to evaluate intra-prostatic cancer volumes for salvage radiotherapy in men with recurrent prostate cancer confined to the prostate post-primary radiotherapy using mpMRI and 18F-DCFPyL PET/CT (PET).

Methods

Men with biochemical failure post-primary radiotherapy were enrolled in a multi-centre trial investigating mpMRI and PET. All men with isolated intra-prostatic recurrence are included in this secondary analysis. The intra-prostatic gross tumour volume (GTV) was manually delineated on mpMRI and was also delineated on PET using three methods: 1. manually, 2. using a 30% threshold of maximum intra-prostatic standard uptake value (SUVmax), and 3. using a 67% threshold of this SUVmax. Clinical target volumes (CTV) including expansions on each GTV were generated. Conformity indices were performed between the mpMRI CTV and each PET CTV. Correlation with biopsy and clinical outcomes were performed.

Results

Of the 36 men included, 30 (83%) had disease in two quadrants or less using the combination of mpMRI and PET. Mean target volume (union of CTV on mpMRI and CTV manually delineated on PET) was 12.2 cc (49% of prostate gland volume). 12/36 (33%) men had a biopsy. Per-patient sensitivity was 91% for mpMRI and 82% for PET.

Conclusions

mpMRI and PET provide complementary information for delineation of intra-prostatic recurrent disease. Union of CTV on mpMRI and PET is often less than 50% of the prostate, suggesting this imaging could help define a target for focal salvage therapy.

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.

Oncologic outcome of salvage high-intensity focused ultrasound (HIFU) in radiorecurrent prostate cancer. A systematic review

INTRODUCTION

External Beam Radiation Therapy (EBRT) is one of the option available for the treatment of clinically localized prostate cancer. In patients with radiorecurrent localized prostate cancer, Androgen Deprivation Therapy (ADT) is one of the most common therapeutic strategies. However, in the last decades, other salvage treatment options have been investigated, such as brachytherapy, cryoablation and High Intensity Focused Ultrasound (Hifu).

MATERIAL AND METHODS

The oncologic outcome of Hifu in a salvage setting after EBRT failure was investigated. We reviewed the literature from 2005 to 2020 in order to report the oncologic outcome of the technique.

RESULTS

A total of 1241 patients were analyzed, with a mean age of 68.6 years and a PSA value of 5.87 ng/mL before treatment. Mean follow-up was 24.3 months after treatment, ranging from 3 to 168 months.

CONCLUSION

Our review of the literature revealed that salvage Hifu is effective in the treatment of radiorecurrent clinically localized prostate cancer, with an overall survival of 85.2% at 5 years.

Focal Therapy for Prostate Cancer: Complications and Their Treatment

Focal therapy is a modern alternative to selectively treat a specific part of the prostate harboring clinically significant disease while preserving the rest of the gland. The aim of this therapeutic approach is to retain the oncological benefit of active treatment and to minimize the side-effects of common radical treatments. The oncological effectiveness of focal therapy is yet to be proven in long-term robust trials. In contrast, the toxicity profile is well-established in randomized controlled trials and multiple robust prospective cohort studies. This narrative review summarizes the relevant evidence on complications and their management after focal therapy. When compared to whole gland treatments, focal therapy provides a substantial benefit in terms of adverse events reduction and preservation of genito-urinary function. The most common complications occur in the peri-operative period. Urinary tract infection and acute urinary retention can occur in up to 17% of patients, while dysuria and haematuria are more common. Urinary incontinence following focal therapy is very rare (0-5%), and the vast majority of patients recover in few weeks. Erectile dysfunction can occur after focal therapy in 0-46%: the baseline function and the ablation template are the most important factors predicting post-operative erectile dysfunction. Focal therapy in the salvage setting after external beam radiotherapy has a significantly higher rate of complications. Up to one man in 10 will present a severe complication.

The clinical guiding value of a radiomics model for androgen deprivation therapy for prostate cancer

OBJECTIVE

Three models were used to evaluate prostate cancer after androgen deprivation therapy (ADT) and to determine the value of detecting residual lesions after treatment.

METHODS

We retrospectively analysed patients with prostate cancer who received ADT from January 2018 to June 2019. Patients were divided into ADT responder and ADT non-responder groups, and clinical risk factors were determined. Regions of interest were manually contoured on each slice on fat-saturated-T2-weighted imaging, and radiomic features were extracted. Uni- and multivariate logistic regression were used to establish radiomics, clinical and combined models.

RESULTS

There were 23 ADT non-responders and 20 ADT responders. In the clinical model, total prostate-specific antigen concentration and T stage were independent predictors of efficacy (area under the curve (AUC) = 0.774). The characteristics, MinIntensity and Correlation_ angle135_offset4 indicated an effective clinical model (AUC = 0.807). GLCMEntropy_ AllDirection_offset1_SD was the best feature to differentiate residual lesions from the central gland (CG) (Lesion-CG model, AUC = 0.955). Correlation_angle135_offset4, GLCMEntropy_ AllDirection_offset4_SD and GLCMEntropy_AllDirection_offset7_SD differentiated residual lesions from the peripheral zone (PZ) (Lesion-PZ model, AUC = 0.855). The AUC for the combined model was 0.904.

CONCLUSIONS

Our models can guide the clinical treatment of patients with different ADT responses. Furthermore, the radiomics model can detect prostate cancer that is non-responsive to ADT.

Development and internal validation of multivariable prediction models for biochemical failure after MRI-guided focal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

Background and purpose

Magnetic resonance-guided focal salvage high-dose-rate brachytherapy (FS-HDR-BT) for radiorecurrent prostate cancer (PCa) shows low toxicity rates. However, biochemical failure (BF) after treatment occurs frequently. We developed two prediction models for BF (Phoenix definition) with the aim of enhancing patient counselling before FS-HDR-BT and during follow-up.

Materials and methods

A prospective cohort of 150 radiorecurrent PCa patients treated with FS-HDR-BT between 2013 and 2020 was used for model development and internal validation. Multivariable Cox Proportional Hazards regression was applied. For model 1, only pre-salvage variables were included as candidate predictors. For model 2, additional (post-)salvage characteristics were tested. After calibration, nomograms and webtools were constructed. Finally, three risk groups were identified.

Results

Sixty-one patients (41%) experienced BF. At baseline (model 1), age, gross tumour volume, pre-salvage PSA, and pre-salvage PSA doubling time (PSADT) were predictive of BF. During follow-up (model 2), age, pre-salvage PSA and PSADT, seminal vesicle involvement, post-salvage time to PSA nadir, and percentage PSA reduction were predictive of BF. The adjusted C-statistics were 0.73 (95% CI: 0.66-0.81) and 0.84 (95% CI: 0.78-0.90), respectively, with acceptable calibration. Estimated 2-year biochemical disease-free survival for the low-, intermediate-, and high-risk groups were 84%, 70%, and 31% (model 1), and 100%, 71%, and 5% (model 2).

Conclusion

Two models are provided for prediction of BF in patients with radiorecurrent PCa treated with FS-HDR-BT. Based on pre- and post-salvage characteristics, we are able to identify patients with a high risk of BF. These findings can aid patient counselling for FS-HDR-BT.

Salvage ablation for locally recurrent prostate cancer

PURPOSE OF REVIEW

This review aims to summarize the latest evidence for the use of salvage ablation of localized prostate cancer recurrences after primary therapy radiotherapy or prostatectomy.

RECENT FINDINGS

Savage ablation represents a treatment option in select patients with localized recurrences following primary therapy of prostate cancer. Following radiotherapy, salvage cryotherapy and high-intensity focused ultrasound (HIFU) demonstrate encouraging oncologic outcomes. Biochemical recurrence-free survival ranged from 71% at 2 years to 44.2% at 10 years for cryotherapy and from 51% at 5 years to 28.7% at 10 years for HIFU. Rates of adverse effects appear to be more favorable with ablation compared to salvage surgery. Focal salvage ablation may offer a further balance between oncologic control and adverse effects. Following radical prostatectomy, recent data on the use of salvage ablation of local recurrences are less robust with only a few small studies published in the last 2 years.

SUMMARY

Salvage ablation is an option for localized disease recurrences following primary treatment. Its role is most established for postradiation recurrence. It can also be utilized in postprostatectomy recurrence, although published data is more limited. Future studies are needed to further explore the role of ablation in both cohorts.

Oncologic outcome of salvage high-intensity focused ultrasound (HIFU) in radiorecurrent prostate cancer. A systematic review

INTRODUCTION

External Beam Radiation Therapy (EBRT) is one of the option available for the treatment of clinically localized prostate cancer. In patients with radiorecurrent localized prostate cancer, Androgen Deprivation Therapy (ADT) is one of the most common therapeutic strategies. However, in the last decades, other salvage treatment options have been investigated, such as brachytherapy, cryoablation and High Intensity Focused Ultrasound (Hifu).

MATERIAL AND METHODS

The oncologic outcome of Hifu in a salvage setting after EBRT failure was investigated. We reviewed the literature from 2005 to 2020 in order to report the oncologic outcome of the technique.

RESULTS

A total of 1241 patients were analyzed, with a mean age of 68.6 years and a PSA value of 5.87 ng/mL before treatment. Mean follow-up was 24.3 months after treatment, ranging from 3 to 168 months.

CONCLUSION

Our review of the literature revealed that salvage Hifu is effective in the treatment of radiorecurrent clinically localized prostate cancer, with an overall survival of 85.2% at 5 years.

Health-related quality of life after ultrafocal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer: reporting the patient’s perspective

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We analyzed patient-reported quality of life in 100 patients who underwent ultrafocal salvage HDR-brachytherapy.

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Patient-reported bowel symptoms were neglible.

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Urinary complaints increased and sexual functioning declined over time.

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Lower impact is predicted for patients with favorable function at baseline and lower dose to the urethra.

Purpose

For patients with a localized prostate cancer recurrence after radiotherapy, focal salvage treatment offers a less toxic alternative to whole-gland treatments, with the potential of preserving health-related quality of life (HR-QoL). With a focus on the patient’s perspective of treatment, this study aims to describe HR-QoL after ultrafocal salvage high-dose-rate brachytherapy (HDR-BT), and to explore predictive factors affecting HR-QoL.

Material and methods

We included 100 patients treated with ultrafocal salvage HDR-BT. Prostate cancer-related HR-QoL was assessed by the EORTC QLQ-PR25 questionnaire. Domains were urinary symptoms, bowel symptoms and sexual activity/functioning. For each domain, a mixed effects model was made to estimate HR-QoL trends over time. For domains showing clinically relevant change (≥10 points difference), the mixed effects model was used to explore potential predictors (age, baseline HR-QoL score, T-stage, tumor location, CTV size, dose to organs at risk and history of ADT).

Results

Median follow-up was 20 months (IQR 13–30). Mean questionnaire response rate was 86% (range 72–100%). Median baseline scores were 12 (urinary), 0 (bowel) and 67/50 (sexual activity/functioning). Urinary symptoms and sexual functioning showed clinically relevant deterioration over time (maximum difference of 11 and 12 points, respectively). Worse baseline score and higher administered dose to the urethra (≥16 Gy) were predictive of increased urinary symptoms (p < 0.01 and p = 0.03). Better baseline score was predictive of better sexual functioning (p < 0.01).

Conclusion

Ultrafocal salvage HDR-BT has negligible impact on bowel symptoms but does affect urinary symptoms and sexual functioning. Lower impact is predicted for patients with favorable urinary and sexual function at baseline. Urethral dose constraints should be closely monitored.