Prostate cancer treatment often involves a difficult choice between effective cancer control and preserving a patient’s quality of life. Traditional whole-gland treatments, such as surgery and radiation, have long-established track records but carry risks of significant side effects. This inherent conflict has driven a search for less invasive options that precisely eliminate cancer while minimizing collateral damage to the surrounding healthy tissue. One technology emerging in this area is Irreversible Electroporation, commercially known as Nanoknife, which offers a targeted approach to managing localized prostate tumors.
Understanding Irreversible Electroporation (Nanoknife)
Irreversible Electroporation (IRE), or Nanoknife, is a non-thermal ablation method that uses electrical energy to destroy cancer cells. Unlike treatments that rely on extreme heat or cold, IRE utilizes high-voltage direct current pulses delivered through thin needle electrodes. These pulses generate a strong electrical field across the targeted tissue, causing permanent, nanoscale pores to form in the cell membranes.
This poration process disrupts the cell’s internal stability, leading to programmed cell death, or apoptosis. This mechanism is selective, primarily affecting cell membranes while theoretically sparing surrounding non-cellular structures. Connective tissues, such as the collagen matrix and neurovascular bundles, are often preserved. This preservation of the tissue scaffold is thought to be the reason for lower rates of functional side effects compared to thermal ablation techniques like cryotherapy or high-intensity focused ultrasound.
How Nanoknife Targets Prostate Cancer (Focal Therapy)
The application of IRE in the prostate is typically performed as a focal therapy, meaning the treatment is precisely limited to the cancerous area. The goal is to ablate the primary tumor, often called the index lesion, while leaving the rest of the prostate gland intact. This strategy aims to achieve cancer control with a lower risk of the side effects associated with treating the entire organ.
The procedure relies on advanced imaging techniques to map the tumor and guide the placement of the electrodes. Multiparametric Magnetic Resonance Imaging (mpMRI) is used before the procedure to delineate the exact location and size of the tumor. During the intervention, real-time ultrasound or MRI-ultrasound fusion technology provides the precision needed to position the needle electrodes around the tumor.
These electrodes are placed transperineally, passing through the skin behind the scrotum and into the prostate. The number and configuration of the needles are carefully selected to ensure the electrical field covers the entire target lesion and a small surrounding margin of tissue. This planning is designed to destroy all cancer cells in the defined area while maximizing the sparing of adjacent healthy structures.
Clinical Data on Treatment Success and Recurrence
The success of Nanoknife for prostate cancer is generally measured by oncological outcomes, such as the absence of cancer in the treated area and the stability of Prostate-Specific Antigen (PSA) levels. In a key clinical trial involving patients with intermediate-risk prostate cancer, 84% of men were free from clinically significant disease in the treated area at 12 months, based on post-treatment biopsy results. Other studies have reported up to a 97% rate in the successful eradication of the index lesion after treatment.
A primary indicator of success is the long-term freedom from needing more aggressive treatments, like radical prostatectomy or radiation. Available clinical data show that failure-free survival rates—meaning no need for salvage therapy—are approximately 91% at three years and 84% at five years in men with localized disease. This suggests that Nanoknife provides durable cancer control for a significant portion of carefully selected patients.
Post-treatment monitoring includes tracking PSA levels, which are expected to decrease as the cancerous tissue is destroyed. In clinical studies, 95% of patients experienced a reduction in their PSA level by the 12-month mark. Because IRE is a focal treatment, recurrence remains a concern, primarily in the untreated areas of the prostate. Recurrence rates in the remaining prostate tissue are reported to be less than 20% at five years of follow-up, necessitating continued active surveillance with regular MRI scans and biopsies. Long-term data extending beyond ten years is still limited compared to established whole-gland therapies.
Patient Suitability and Functional Outcomes
Patient suitability for Nanoknife is highly specific, as the procedure is best suited for focal therapy. The ideal candidate typically has localized prostate cancer that is either low or intermediate-risk, corresponding to Gleason scores of 6 or 7 (such as 3+4 or 4+3). Tumors must be clearly identifiable on imaging, generally with a maximum size around 15 millimeters, and the PSA level is often required to be below 15 ng/mL. Patients with tumors extending significantly outside the prostate or with high-risk disease are usually better served by traditional radical treatments.
A primary appeal of Nanoknife is its potential to preserve a patient’s quality of life by minimizing damage to surrounding organs and nerve bundles. Functional outcomes related to urinary continence and sexual health are often significantly better than those reported for surgery or radiation. Clinical data indicate that the preservation of urinary continence is exceptionally high, with rates ranging from 95% to nearly 100% of patients remaining pad-free.
Preservation of erectile function is also a significant benefit, with studies reporting that 80% to 88% of men with good baseline function maintain sufficient potency for sexual activity after the procedure. This high rate is attributed to the non-thermal nature of IRE, which allows for the sparing of the delicate neurovascular bundles responsible for erectile function. While the risk of side effects is low, temporary urinary issues or mild discomfort can occur immediately following the procedure.