Focal therapy with high-intensity focused ultrasound for prostate cancer: 3-year outcomes from a prospective trial

Established focal therapy-HIFU, IRE, or cryotherapy-where are we now?-a systematic review and meta-analysis

INTRODUCTION

Focal Therapy (FT) is a treatment option for the treatment of limited volume clinically significant prostate cancer (csPCa). We aim to systematically review outcomes of established FT modalities to assess the contemporary baseline and identify gaps in evidence that will aid in further trial and study design.

METHODS

We conducted a systematic review and meta-analysis of all primary studies reporting outcomes of FT using cryotherapy, high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE). We described patient inclusion criteria, selection tools, treatment parameters, and surveillance protocols, and pooled overall survival (OS), cancer-specific survival (CSS), metastasis-free survival (MFS), biochemical progression (BP), biopsy, secondary treatment, sexual, and urinary function outcomes. Composite failure was defined as salvage whole gland ablation, radical treatment, hormonal therapy or transition to watchful waiting.

SYNTHESIS

We identified 49 unique cohorts of men undergoing FT between 2008 and 2024 (21 cryotherapy, 20 HIFU, and 8 IRE). Median follow-up ranged from 6 to 63 months. Pooled OS was 98.0%, CSS 99.3%, and MFS 98.5%. Pooled BP was 9.4%/year. Biopsy was mandated post-FT within 24 months in 36/49 (73.5%) cohorts, with pooled csPCa (GG ≥ 2) rates of 22.2% overall, 8.9% infield, and 12.3% outfield. The pooled rate of secondary FT was 5.0%, radical treatment 10.5%, and composite failure 14.1%. Of 35 studies reporting sexual function, 45.7% reported a low, 48.6% moderate, and 5.7% severe impact. For 34 cohorts reporting urinary function, 97.1% reported a low impact. No differences were noted between cryotherapy, HIFU, or IRE in any of the outcomes.

CONCLUSION

FT with cryotherapy, HIFU, and IRE is associated with good short-intermediate term oncological and functional outcomes. However, outcome reporting is heterogeneous and often incomplete. Long-term follow-up and standardized reporting are required to better define and report FT outcomes.

Surveillance after Focal Therapy - a Comprehensive Review

BACKGROUND

to date, no standardized, evidence-based follow-up schemes exist for the monitoring of patients who underwent focal therapy (FT) and expert centers rely mainly on their own experience and/or institutional protocols. We aimed to perform a comprehensive review of the most advantageous follow-up strategies and their rationale after FT for prostate cancer (PCa).

METHODS

a narrative review of the literature was conducted to investigate different follow-up protocols of FT for PCa. Outcomes of interest were post-ablation oncological and functional outcomes and complications.

RESULTS

Oncological success after FT was generally defined as the biopsy-confirmed absence of clinically significant PCa in the treated zone. De novo PCa in the untreated area usually reflects an inaccurate patient selection and should be treated as primary PCa. During follow-up, oncological outcomes should be evaluated with periodic PSA, multiparametric MRI and prostate biopsy. The use of PSA derivatives and new biomarkers is still controversial and therefore not recommended. The first MRI after FT should be performed between 6-12 months to avoid ablation-related artifacts and diagnostic delay in case of FT failure. Other imaging modalities, such as PSMA PET/CT scan, are promising but still need to be validated in the post-FT setting. A 12-month "for-protocol" prostate biopsy, including targeted and systematic biopsy, was generally considered the preferred biopsy method to rule out tumor persistence/recurrence. Subsequent mpMRIs and biopsies should follow a risk-adapted approach depending on the clinical scenario. Functional outcomes should be periodically assessed using validated questionnaires within the first year, when typically recover to a new baseline. Complications, despite uncommon, should be strictly monitored mainly in the first month.

CONCLUSIONS

FT follow-up is a multifaceted process involving clinical, radiological, and histological assessment. Studies evaluating the impact of different follow-up strategies and ideal timings are needed to produce standardized protocols following FT.

Therapeutic ultrasound transducer technology and monitoring techniques: a review with clinical examples

The exponential growth of therapeutic ultrasound applications demonstrates the power of the technology to leverage the combinations of transducer technology and treatment monitoring techniques to effectively control the preferred bioeffect to elicit the desired clinical effect.Objective: This review provides an overview of the most commonly used bioeffects in therapeutic ultrasound and describes existing transducer technologies and monitoring techniques to ensure treatment safety and efficacy.Methods and materials: Literature reviews were conducted to identify key choices that essential in terms of transducer design, treatment parameters and procedure monitoring for therapeutic ultrasound applications. Effective combinations of these options are illustrated through descriptions of several clinical indications, including uterine fibroids, prostate disease, liver cancer, and brain cancer, that have been successful in leveraging therapeutic ultrasound to provide effective patient treatments.Results: Despite technological constraints, there are multiple ways to achieve a desired bioeffect with therapeutic ultrasound in a target tissue. Visualizations of the interplay of monitoring modality, bioeffect, and applied acoustic parameters are presented that demonstrate the interconnectedness of the field of therapeutic ultrasound. While the clinical indications explored in this review are at different points in the clinical evaluation path, based on the ever expanding research being conducted in preclinical realms, it is clear that additional clinical applications of therapeutic ultrasound that utilize a myriad of bioeffects will continue to grow and improve in the coming years.Conclusions: Therapeutic ultrasound will continue to improve in the next decades as the combination of transducer technology and treatment monitoring techniques will continue to evolve and be translated in clinical settings, leading to more personalized and efficient therapeutic ultrasound mediated therapies.