Oncological long-term outcome of whole gland HIFU and open radical prostatectomy: a comparative analysis

Oncological and Functional Outcomes of Whole-Gland HIFU as the Primary Treatment for Localized Prostate Cancer: A Systematic Review

INTRODUCTION

High-intensity focused ultrasound (HIFU) is regarded as a promising alternative treatment option for localized prostate cancer (PCa) as it has been proposed to offer similar oncologic control to the standard of care, but with significantly reduced treatment-related side effects. This systematic literature review assesses the available evidence of whole-gland HIFU as primary treatment for localized PCa.

METHODS

MEDLINE (PubMed) was searched for studies investigating oncological and functional outcomes following whole-gland HIFU as primary treatment for localized PCa. Our primary outcomes for the review were biochemical disease-free survival rates (BDFS), overall and PCa-specific survival rates as well as negative biopsy rates. Our secondary outcomes were functional results and complications of the treatment.

RESULTS

A total of 375 articles were identified, of which 35 were included in the present review. All 35 articles were prospective or retrospective case series. Mean/median duration of follow-up across studies was 10.9 to 94 months, and 6618 patients were included in the review. The BDFS rate varied greatly across studies from 21.7% to 89.2% during follow-up. The 10-year PCa-specific survival rate following HIFU was 90%, 99%, and 100% in 3 studies. Negative biopsy rates post-HIFU ranged from 20% to 92.7% across studies. Common side effects to HIFU included urinary incontinence (grade 1: 0%-22.7%), erectile dysfunction (11.6%-77.1%), urinary tract infections (1.5%-47.9%), and bladder outlet obstruction mainly as urethral strictures (7%-41.2%).

CONCLUSION

Great variation in oncological and functional outcomes was seen across studies. More prospective trials are needed before whole-gland HIFU can be considered as a treatment option for localized PCa.

Primary Whole-gland Ablation for the Treatment of Clinically Localized Prostate Cancer: A Focal Therapy Society Best Practice Statement

CONTEXT

Whole-gland ablation is a feasible and effective minimally invasive treatment for localized prostate cancer (PCa). Previous systematic reviews supported evidence for favorable functional outcomes, but oncological outcomes were inconclusive owing to limited follow-up.

OBJECTIVE

To evaluate the real-world data on the mid- to long-term oncological and functional outcomes of whole-gland cryoablation and high-intensity focused ultrasound (HIFU) in patients with clinically localized PCa, and to provide expert recommendations and commentary on these findings.

EVIDENCE ACQUISITION

We performed a systematic review of PubMed, Embase, and Cochrane Library publications through February 2022 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. As endpoints, baseline clinical characteristics, and oncological and functional outcomes were assessed. To estimate the pooled prevalence of oncological, functional, and toxicity outcomes, and to quantify and explain the heterogeneity, random-effect meta-analyses and meta-regression analyses were performed.

EVIDENCE SYNTHESIS

Twenty-nine studies were identified, including 14 on cryoablation and 15 on HIFU with a median follow-up of 72 mo. Most of the studies were retrospective (n = 23), with IDEAL (idea, development, exploration, assessment, and long-term study) stage 2b (n = 20) being most common. Biochemical recurrence-free survival, cancer-specific survival, overall survival, recurrence-free survival, and metastasis-free survival rates at 10 yr were 58%, 96%, 63%, 71-79%, and 84%, respectively. Erectile function was preserved in 37% of cases, and overall pad-free continence was achieved in 96% of cases, with a 1-yr rate of 97.4-98.8%. The rates of stricture, urinary retention, urinary tract infection, rectourethral fistula, and sepsis were observed to be 11%, 9.5%, 8%, 0.7%, and 0.8%, respectively.

CONCLUSIONS

The mid- to long-term real-world data, and the safety profiles of cryoablation and HIFU are sound to support and be offered as primary treatment for appropriate patients with localized PCa. When compared with other existing treatment modalities for PCa, these ablative therapies provide nearly equivalent intermediate- to long-term oncological and toxicity outcomes, as well as excellent pad-free continence rates in the primary setting. This real-world clinical evidence provides long-term oncological and functional outcomes that enhance shared decision-making when balancing risks and expected outcomes that reflect patient preferences and values.

PATIENT SUMMARY

Cryoablation and high-intensity focused ultrasound are minimally invasive treatments available to selectively treat localized prostate cancer, considering their nearly comparable intermediate- to long term cancer control and preservation of urinary continence to other radical treatments in the primary setting. However, a well-informed decision should be made based on one's values and preferences.

Immune checkpoint inhibition: a future guided by radiology

The limitation of the function of antitumour immune cells is a common hallmark of cancers that enables their survival. As such, the potential of immune checkpoint inhibition (ICI) acts as a paradigm shift in the treatment of a range of cancers but has not yet been fully capitalised. Combining minimally and non-invasive locoregional therapies offered by radiologists with ICI is now an active field of research with the aim of furthering therapeutic capabilities in medical oncology. In parallel to this impending advancement, the "imaging toolbox" available to radiologists is also growing, enabling more refined tumour characterisation as well as greater accuracy in evaluating responses to therapy. Options range from metabolite labelling to cellular localisation to immune checkpoint screening. It is foreseeable that these novel imaging techniques will be integrated into personalised treatment algorithms. This growth in the field must include updating the current standardised imaging criteria to ensure they are fit for purpose. Such criteria is crucial to both appropriately guide clinical decision-making regarding next steps of treatment, but also provide reliable prognosis. Quantitative approaches to these novel imaging techniques are also already being investigated to further optimise personalised therapeutic decision-making. The therapeutic potential of specific ICIs and locoregional therapies could be determined before administration thus limiting unnecessary side-effects whilst maintaining efficacy. Several radiological aspects of oncological care are advancing simultaneously. Therefore, it is essential that each development is assessed for clinical use and optimised to ensure the best treatment decisions are being offered to the patient. In this review, we discuss state of the art advances in novel functional imaging techniques in the field of immuno-oncology both pre-clinically and clinically.

High intensity focused ultrasound for the treatment of solid tumors: a pilot study in canine cancer patients

PURPOSE

To investigate the safety, feasibility, and outcomes of High-Intensity Focused Ultrasound (HIFU) for the treatment of solid tumors in a spontaneous canine cancer model.

METHODS

Dogs diagnosed with subcutaneous solid tumors were recruited, staged and pretreatment biopsies were obtained. A single HIFU treatment was delivered to result in partial tumor ablation using a commercially available HIFU unit. Tumors were resected 3-6 days post HIFU and samples obtained for histopathology and immunohistochemistry. Total RNA was isolated from paired pre and post treated FFPE tumor samples, and quantitative gene expression analysis was performed using the nCounter Canine IO Panel.

RESULTS

A total of 20 dogs diagnosed with solid tumors were recruited and treated in the study. Tumors treated included Soft Tissue Sarcoma (n = 15), Mast Cell Tumor (n = 3), Osteosarcoma (n = 1), and Thyroid Carcinoma (n = 1). HIFU was well tolerated with only 1 dog experiencing a clinically significant adverse event. Pathology confirmed the presence of complete tissue ablation at the HIFU targeted site and immunohistochemistry indicated immune cell infiltration at the treated/untreated tumor border. Quantitative gene expression analysis indicated that 28 genes associated with T-cell activation were differentially expressed post-HIFU.

CONCLUSIONS

HIFU appears to be safe and feasible for the treatment of subcutaneous canine solid tumors, resulting in ablation of the targeted tissue. HIFU induced immunostimulatory changes, highlighting the canine cancer patient as an attractive model for studying the effects of focal ablation therapies on the tumor microenvironment.

Comparing the toxicity and disease control rate of radiotherapy for prostate cancer between salvage settings after high-intensity focused ultrasound therapy and initial settings

The purpose of this retrospective study was to compare the toxicity and disease control rate of radiotherapy for prostate cancer in salvage settings after high-intensity focused ultrasound (HIFU) therapy (HIFU cohort) with those in radical settings (non-HIFU cohort). From 2012 to 2020, 215 patients were identified for this study and 17 were treated in the salvage settings after HIFU. The median follow-up time was 34.5 months (range: 7-102 months, inter-quartile range [IQR]: 16-64 months). Genitourinary (GU) and gastrointestinal (GI) adverse events were evaluated in acute and late periods with Common Terminology Criteria for Adverse Events version 5, and the rates of biochemical-clinical failure free survival (BCFS) and overall survival (OS) were estimated. The cumulative incidence of late GU Grade 2 or greater toxicity after five years was significantly different between the non-HIFU and HIFU cohorts with rates of 7.3% and 26.2%, respectively (P = 0.03). Regarding GI Grade 2 or greater toxicity, there was no significant difference between the two cohorts. The 5y-BCFS was 84.2% in the non-HIFU cohort and 69.5% in the HIFU cohort with no significant difference (P = 0.10) and the 5y-OS was 95.9% and 92.3%, respectively (P = 0.47). We concluded that the possibility of increased late GU Grade 2 or greater should be considered when applying salvage radiotherapy for local recurrence after HIFU.

Long-term outcomes of whole gland high-intensity focused ultrasound for localized prostate cancer

OBJECTIVES

To report the 10-year oncologic and functional outcomes of whole-gland HIFU as first-line treatment for localized prostate cancer (PCa).

PATIENTS AND METHODS

Patients were retrospectively included between January 2005 and July 2018 from a prospectively maintained database at a single academic institution. No patient underwent androgen deprivation therapy prior to HIFU. Primary endpoint was biochemical recurrence-free survival (BRFS). Secondary oncological endpoints included salvage treatment-free survival (STFS), cancer-specific survival (CSS) and overall survival (OS).

RESULTS

A total of 97 patients met our inclusion criteria and were included in the final analysis. According to D'Amico classification, the numbers of patients with low-, intermediate-, and high-risk disease were 38 (39.2%), 52 (53.6%), and 7 (7.2%). A total of 21 (21.6%) patients received salvage treatment at a mean of 4.1 years (± 2.8) after HIFU. The 10-year OS, CSS and BRFS rates were 91.8%, 100% and 40.3% in the overall cohort, respectively. In multivariate analysis, predictive factors for biochemical recurrence were intermediate-risk group (RR = 2.065; 95% CI 1.008-4.230; p = 0.047) and PSA nadir > 0.5 ng/mL (RR = 4.963; 95% CI 2.251-10.947; p < 0.001). Symptoms related to bladder outlet obstruction were the most frequently recorded adverse events. In multivariate analysis, positive biopsy on the prostatic apex was predictor of obstructive complications (RR = 3.2, 95% CI 1.092-9.476, p = 0.034). Only four patients developed severe urinary incontinence (> 1 pad/day).

CONCLUSIONS

HIFU showed low PCa-specific mortality, but biochemical recurrence rates were highly variable among patients. Future studies are needed to improve patient selection.

Applications of Focused Ultrasound in the Treatment of Genitourinary Cancers

Simple Summary

Cancer is a prevalent disease globally, and conventional treatment options have been associated with substantial morbidity for patients. The unique acoustic properties and biological effects of focused ultrasound have been investigated for use as an alternative treatment option for various forms of cancer with lower associated morbidity than standard treatments. The objective of our review was to assess the current state and various applications of focused ultrasound for the treatment of genitourinary cancers, including prostate, kidney, bladder, penile, and testicular malignancies. Current research demonstrates that focused ultrasound-based focal therapy shows promise for the treatment of localized prostate and kidney cancer, and the effect of ultrasound on cell membranes may increase the efficacy of chemotherapeutics and radiotherapy. Focused ultrasound-based treatment modalities should continue to be investigated as an alternative or complementary treatment option for cancer patients.

Abstract

Traditional cancer treatments have been associated with substantial morbidity for patients. Focused ultrasound offers a novel modality for the treatment of various forms of cancer which may offer effective oncological control and low morbidity. We performed a review of PubMed articles assessing the current applications of focused ultrasound in the treatment of genitourinary cancers, including prostate, kidney, bladder, penile, and testicular cancer. Current research indicates that high-intensity focused ultrasound (HIFU) focal therapy offers effective short-term oncologic control of localized prostate and kidney cancer with lower associated morbidity than radical surgery. In addition, studies in mice have demonstrated that focused ultrasound treatment increases the accuracy of chemotherapeutic drug delivery, the efficacy of drug uptake, and cytotoxic effects within targeted cancer cells. Ultrasound-based therapy shows promise for the treatment of genitourinary cancers. Further research should continue to investigate focused ultrasound as an alternative cancer treatment option or as a complement to increase the efficacy of conventional treatments such as chemotherapy and radiotherapy.

First experiences and results after cryoablation of prostate cancer with histopathological evaluation and imaging-based follow-up

Aim: To share our experience after 28 cryoablation treatments for prostate cancer (PCa) with histopathology, clinical data and MRI as the follow-up methods. Methods: Clinical follow-up comprised prostate specific antigen (PSA)-measurements, PSA-density and quality-of-life-parameters. multi-parametric (mp)MRI pre- and post-cryoablation were retrospectively re-analyzed in 23 cases using Likert scores. Follow-up-histopathology was performed via MRI/ultrasound fusion-guided and/or systematic biopsy. Receiver operating characteristic curve analysis was performed. Results: 17 PCa (61%) were diagnosed within 12-month post-cryotherapy (infield and out-of-field disease). PSA levels and PSA density were not significantly different between patients with or without PCa recurrence. mpMRI can characterize the decrease in prostate volume and necrosis. Area under the curve for the detection of PCa was 81% (global Likert scores), 74-87% (T2), 78% (diffusion weighted imaging) and 57-78% (dynamic contrast enhanced imaging; Youden-selected cutoff ≥3). Conclusion: Besides histopathological evaluation and control biopsy, MRI might have the potential to accurately detect PCa after cryotherapy. Clinical data and interdisciplinary communication are required for efficient monitoring after cryoablation treatments for PCa.

Oncological Long-term Outcome After Whole-gland High-intensity Focused Ultrasound for Prostate Cancer-21-yr Follow-up

BACKGROUND

Owing to the morbidity of established radical treatment options for prostate cancer, alternative whole-gland and focal treatment strategies have emerged. High-intensity focused ultrasound (HIFU) is one of the most studied sources for tissue ablation and has been used since the 1990s.

OBJECTIVE

To provide 21-yr oncological long-term follow-up data of an unselected series of patients who underwent whole-gland HIFU for nonmetastatic prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

A total of 674 patients were treated between November 1997 and November 2012 in one university center.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The oncological outcome was assessed by biopsy failure-free survival (BFFS), salvage treatment-free survival (STFS), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS). Multivariable Cox proportional hazard regression analyses were performed to estimate the prognostic relevance of clinical variables.

RESULTS AND LIMITATIONS

In total, 560 patients were included into the evaluation and the median follow-up was 15.1 yr, with a range up to 21.4 yr. At 15 yr, CSS rates for low-, intermediate-, and high-risk patients were 95%, 89%, and 65%, respectively; MFS, STFS-1 (salvage treatment other than HIFU), STFS-2 (salvage treatment including repeat HIFU), and BFFS rates were 91%, 85%, and 58%; 77%, 63%, and 29%; 67%, 52%, and 28%; and 82%, 73%, and 47%, respectively. Preoperative high-risk category was an independent predictor of inferior OS, CSS, MFS, STFS, and BFFS.

CONCLUSIONS

Although whole-gland HIFU achieved good long-term cancer control in low- and intermediate-risk patients, high-risk patients should not be treated routinely by HIFU. Intermediate-risk patients achieve high CSS and MFS rates, but a relevant salvage treatment rate has to be reckoned with. Long-term data after whole-gland therapy might help derive implications for focal treatment sources and patient selection.

PATIENT SUMMARY

Long-term data after whole-gland high-intensity focused ultrasound (HIFU) therapy are crucial to prove its oncological efficacy, and may help derive implications for focal treatment strategies and patient selection. In this context, whole-gland HIFU achieved good long-term cancer control up to 21 yr in low- and intermediate-risk prostate cancer (PCa) patients. Owing to considerably inferior long-term cancer control, it should not routinely be used in high-risk PCa patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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