Case study: Pulsed electric field ablation for salvage prostate cancer ablation

Abstract

Pulsed Electric Field (PEF) ablation is an emerging non-thermal ablation device with previous uses in lung, liver and sarcoma cancers. We present a case of prostate cancer recurrence post-radiation managed with PEF ablation. Under transperineal guidance, targeted PEF was delivered to the area of concern on previous biopsies and PSMA. In follow up the patient had a marked decline in PSA levels and resolution on follow-up PSMA. The patient experienced no significant side effects, preserving urinary continence and sexual function. These outcomes underscore PEF ablation’s potential as a safe and effective salvage therapy with minimal impact on quality of life.

1 Introduction

Prostate cancer recurrence after radiation therapy presents a significant clinical challenge. Traditional salvage treatments include radical prostatectomy, androgen deprivation therapy (ADT), cryotherapy, high-intensity focused ultrasound (HIFU), and stereotactic body radiation therapy (SBRT). However, each of these options comes with significant morbidity, including risks of urinary incontinence, erectile dysfunction, and damage to surrounding organs.

The emergence of novel ablation techniques that do not rely on ionizing radiation or extreme temperatures treat cancer has started to shift the paradigm and expectations for morbidity profiles for focal ablation. These include histotripsy, irreversible electroporation (IRE), and Aliya® pulsed electric fields (PEF). Histotripsy relies on cavitation bubble impacts to destroy cells, but has not been tested in the prostate space, and thus is not described further in this article.

The use of IRE has been evaluated extensively in the preclinical and clinical prostate space, with the greatest level of data The Aliya system (Galvanize Therapeutics, CA, USA) delivers high-voltage, short-duration electrical pulses locally to tumors, disrupting cell membranes and causing cell death without significant thermal damage. Unlike traditional thermal ablation therapies, both technologies provide evidence for the ability to provide focal ablation while preserving surrounding critical structures such as neurovascular bundles and the urethral sphincter.

Aliya PEF received clearance in June 2022 for the surgical ablation of soft tissue. Data for its safety and technical use are described in a case study, which illustrates the use of Aliya PEF in a patient with advanced prostate cancer and rising PSA, demonstrating local tumor control and systemic PSA resolution.

Here, we present our first experience with Aliya PEF for prostate ablation. This case study illustrates the application of Aliya PEF in a patient with biochemical recurrence post-radiation therapy, highlighting its efficacy in reducing PSA levels and preserving quality of life.

2 Case presentation

2.1 Patient history

Patient: 66-year-old male.

Initial Diagnosis: Prostate adenocarcinoma, Gleason 3 + 3 (Grade Group 1) in 2002.

Initial Treatment.

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December 2002: Brachytherapy
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January 2003: 45Gy IMRT
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No androgen deprivation therapy (ADT) was administered
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Achieved undetectable PSA post-treatment

Post-Treatment Course.

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The patient remained in biochemical remission with undetectable PSA for several years
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Developed urethral strictures as a late radiation side effect, requiring periodic dilations
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PSA remained stable until 2019, when a gradual rise was noted

PSA Trend.

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2009–2015: PSA remained low (<0.1 ng/mL)
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2019: PSA increased to 0.256 ng/mL
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2021: PSA reached 0.98 ng/mL, continuing to rise
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2023: PSA climbed to 1.63 ng/mL
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July 2024: PSA at 2.23 ng/mL
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August 2024: PSA at 2.38 ng/mL

2.2 Clinical evaluation

Due to the rising PSA, the patient was referred to medical oncology for evaluation of biochemical recurrence. He remained asymptomatic, with no bone pain, hematuria, or obstructive voiding symptoms. His Eastern Cooperative Oncology Group (ECOG) performance status was 0.

A PSMA PET scan (September 2024) revealed.

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Focal PSMA uptake in the left seminal vesicle, suspicious for local recurrence
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Presacral PSMA-avid focus, indeterminate but likely representing sympathetic ganglia

Given the absence of widespread metastatic disease and the localized nature of recurrence, the patient was considered a candidate for salvage focal therapy rather than systemic treatment.

Following Aliya PEF treatment, the patient’s PSA showed a significant decline.

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Pre-IRE PSA (August 2024): 2.38 ng/mL
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Post-IRE PSA (October 2024): 1.02 ng/mL (57 % reduction)
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Follow-up PSA (January 2025): 0.62 ng/mL

A PSMA PET scan (December 2024) showed significant reduction in PSMA uptake at the treated seminal vesicle site, indicating successful tumor ablation with no evidence of new lesions.

The patient reported no new urinary or sexual dysfunction and remains asymptomatic at follow-up. Figs. 1 and 2 demonstrates the ultrasound and needle position.