March/April 2026 Issue
PEF Therapy
By Beth W. Orenstein
Radiology Today
Vol. 27 No. 2 P. 10
Pulsed electric field ablation offers a new tool for interventional oncology.
Metastatic nonsmall cell lung cancer (NSCLC) carries a grim prognosis, with a five-year survival rate of just 12%, according to the American Cancer Society. Yet over the last decade, outcomes have been gradually improving, as advances in targeted therapies and immunotherapy have extended survival for some patients. Now, another emerging approach—pulsed electric field (PEF) therapy—is drawing attention and offering new hope in lung cancer care. Early research suggests the technique may offer promising short-term outcomes when incorporated into multidisciplinary treatment strategies for patients with primary and metastatic lung malignancies.
A study published online at the end of October 2025 in the medical journal Cancers showed that Galvanize Therapeutics Inc’s Aliya System for PEF ablation achieved meaningful control of lung tumors in metastatic cancer patients. The multicenter AFFINITY clinical trial describes six-month results for 28 evaluable patients who received lung tumor ablation, followed by additional standard-of-care treatment, when deemed appropriate by physicians treating them as well as multidisciplinary team members. Originally, 31 patients were enrolled.
The AFFINITY trial demonstrated that PEF ablation, when performed at the same time as diagnostic biopsy, is safe and does not prevent patients from undergoing subsequent additional therapies. Both patients on concurrent therapy and those with no additional therapy saw high local control rates of ablated tumors: 94% in 16 patients on concurrent therapy and 100% in 12 patients who had been given no additional therapy. The results also suggest that Aliya PEF may activate a systemic immune response in patients with stage IV NSCLC or metastasis to the lung who are not candidates for surgery, potentially broadening the therapeutic landscape in advanced lung cancer.
Local Control
The PEF ablation procedure was successfully delivered in 100% of patients. The researchers report that the procedures were well tolerated, including bilateral ablations. “The six-month data showed this was safe, with 96% local control rate, which is pretty remarkable,” says Bradley B. Pua, MD, an interventional radiologist at New York-Presbyterian Hospital/Weill Cornell Medical Center and a pioneering investigator in the use of the Aliya PEF System for treating lung tumors. Pua has been performing ablation—radiofrequency ablation, cryoablation, microwave ablation—for much of his career, particularly in the lungs. “I’ve pretty much done it all,” he says.
The researchers reported that “there were no delays to standard-of-care therapy and only one percutaneous procedure-related serious adverse event (pneumothorax). “And it resolved without aftereffects,” Pua says. Moreover, he notes, pneumothorax is already considered a common risk in lung interventions.
Unlike traditional thermal ablation techniques, Aliya PEF uses short-duration, high-voltage electrical pulses to induce cell death without damaging surrounding sensitive structures. This innovative approach is delivered either percutaneously or endoscopically with a special flex needle, Galvanize’s INUMI.
“What’s unique about this technique,” Pua says, “is that it results in cell death via nonthermal mechanisms. It delivers targeted electrical pulses that destabilize the cell membrane, disrupt cellular homeostasis, and results in regulated cell death.” Because the cells are dying gradually rather than through an immediate thermal injury, Pua says, “there’s a thought that this slow release of tumor contents may be causing some sort of immune response.”
The Aliya PEF System and percutaneous needle were 510(k) cleared by the FDA for the surgical ablation of soft tissue in June 2022. Subsequently the INUMI Flex Needle was cleared in May 2024. They are not commercially available outside the United States.
Cautious Optimism
Because PEF ablation does not rely on temperature (heat or cold), it may offer meaningful safety advantages, especially in patients whose lung tumors are located in anatomically challenging areas, Pua says. Thermal ablation is often limited near nerves, major blood vessels, and critical organs due to the risk of collateral damage. Early studies suggest PEF ablation can be performed in closer proximity to these structures.
“In small studies, this has been shown to be feasible next to structures we normally can’t treat with thermal energy,” he says. “Because this is nonthermal, in theory—and now in small studies—you can perform PEF ablation next to nerves, blood vessels, and critical organs where thermal ablation isn’t safe.” This anatomical advantage may help expand the range of pulmonary lesions amenable to image-guided intervention, Pua says.
Pua notes that PEF ablation is not a replacement for thermal techniques, which remain highly effective for small, localized tumors. Thermal ablation can create substantially larger ablation zones and is well supported by long-term outcome data. “For small primary lung tumors, I would still use thermal ablation,” he says. “I see PEF as a complementary technique.”
PEF ablation’s niche may lie in patients with metastatic lung cancer, particularly those with a higher tumor burden who are not candidates for surgery and who have limited systemic therapy options. Pua is cautious when presenting the treatment option to his patients. However, he says, “I am starting to incorporate this more routinely because, for many of these patients, there simply aren’t other options.”
Pua has increasingly applied PEF ablation in patients with metastatic lung disease, including those with more than six pulmonary nodules—a population historically associated with poor outcomes. In a small subset of patients, tumors that were not directly treated have demonstrated shrinkage or stabilization following ablation of a single lesion.
“Some patients are showing stability of disease far longer than expected,” Pua says, “and, in a small number, untreated tumors are actually shrinking. If you treat a specific tumor, others that are not treated are starting to be affected. That’s something we really haven’t seen with thermal ablation.”
The results are making researchers “cautiously optimistic,” Pua says. “Oncology has been looking for the abscopal effect, where localized therapy to a single tumor causes the regression of untreated, metastatic tumors elsewhere in the body, for decades,” and this may be a step toward that holy grail, he says.
Based on unpublished personal data, Pua says, about 6% to 8% of patients have demonstrated nontarget effects, while up to 40% to 50% have experienced prolonged disease stability beyond anticipated timelines. “These observations have occurred in some cases without changes to systemic therapy,” he says.
Easy to Integrate
From a procedural standpoint, PEF ablation has been relatively easy to integrate into lung cancer practice, Pua says. It uses a 19-gauge needle, which is smaller than most ablation probes. The smaller needle can be delivered through the same coaxial system used for biopsy, eliminating the need for the patient to undergo additional punctures.
“It was remarkably straightforward to learn, and it doesn’t significantly add to procedure or anesthesia time,” Pua says.
Some thermal modalities require extensive planning around heat sinks, margins, and collateral damage. PEF’s nonthermal mechanism simplifies many procedural considerations. As a result of its ease of adoption, Pua could see it being used more broadly rather quickly, particularly in practices already comfortable with image-guided pulmonary and soft tissue interventions.
Another interventional radiologist, William H. Moore, MD, of NYU Langone, who specializes in diagnosing and treating lung conditions, with a particular focus on lung cancer, also is impressed with PEF. He finds PEF “very similar to biopsy.” He found it very easy to learn and believes “anyone with a background in interventional procedures would be able to pick this up quickly.”
Moore notes that this well-tolerated technology, suitable for hard-to-treat lesions, has expanded his patient base. “This is easier to perform and can be faster to get started with ablation than other techniques,” he says. The only limitation Moore sees is the small size of the ablation zone, about 1.2 cm per activation.
Moore authored two multicenter retrospective studies on PEF, both published in June 2025, one in the journal Lung Cancer and one in the European Journal of Radiology. They contain the largest body of evidence to date on the success of PEF. The Lung Cancer study concludes “that the use of PEF in the setting of progressive [NSCLC] was associated with increased survival compared to a matched cohort.” The European Journal of Radiology study found “percutaneous PEF is feasible to be performed across a variety of organs. Although difficult to compare with other modalities, this data suggests that PEF ablation is relatively safe.”
However, in the conclusion of both studies, Moore wrote that more research is needed. In the first, he wrote: “Prospective controlled studies are required to confirm these preliminary findings, to better understand the mechanism of action of PEF, and to identify which patient populations would best benefit from this therapy.” And in the second, he concludes: “Further prospective studies with larger sample sizes and comprehensive imaging are needed to confirm these findings and establish efficacy.”
Still Evolving
Although there is excitement about PEF’s initial outcomes in lung cancer, some thoracic interventional oncologists remain cautious about considering it a practice-changing advancement. Robert Suh, MD, of UCLA, who has 30 years of experience in lung ablation, views the technology as promising—but still very much in evolution. Suh, director of thoracic interventional services at the David Geffen School of Medicine, is an author of a study published in November 2024 in the Journal of Vascular and Interventional Radiology that was the first clinical series paper on PEF.
Suh believes that ablation is one of the best oncologic treatments for lung cancer because it is minimally invasive, often outpatient, with shorter recovery and less pain than surgery. It preserves lung function in nonsurgical candidates, even when performed multiple times. “It targets tumors precisely, avoiding systemic side effects and immunosuppression associated with chemotherapy,” he says.
For early-stage NSCLC or oligometastatic disease to the lung, “it offers high local control (up to 90% for small tumors) without risks associated with surgical resection such as infection or prolonged hospitalization, and risks accompanying general anesthesia.” Suh says ablation is “ideal for patients with poor lung function that might not withstand a lung resection and those with medical comorbidities, advanced age and frailty, or refusing surgery.”
PEF ablation, Suh says, “shows promise for immune activation, potentially enhancing systemic responses beyond local control.” However, as a standalone ablation tool, PEF has significant limitations. First, Suh says, it creates only a small zone, requiring multiple overlaps that may not reliably control even small tumors (less than 1 cm), especially since the ablation zone is not visible on CT, the main imaging modality in which lung ablation is performed. “In its current state, PEF relies more on evoking or augmenting local target or off-target immune responses rather than direct tumor eradication,” Suh says.
Moreover, Suh says, in the AFFINITY trial’s “ablation-only” subgroup (n=12), “We assume PEF achieved control based solely on imaging (four partial response, eight stable disease) but without follow-up tissue sampling, we do not know if tumors were completely ablated with some certainty. It is unlikely to have eradicated the disease in the traditional ablation sense, as no complete responses were seen and ablated tumor sizes reduced but did not disappear.”
More Research Needed
Suh believes the AFFINITY trial’s small size, heterogeneity, and short follow-up may overstate its efficacy. “Ninety-six percent control may reflect indolent disease rather than true durability,” he says. Although there is some data, questions remain regarding PEF’s efficacy for larger (greater than 2 cm) or multifocal lung tumors. “It may require general anesthesia if performed bronchoscopically, and lacks randomized comparisons to alternatives,” Suh says.
Suh also believes that while PEF is promising for further trials, especially in combination therapies, it is not ready for broad adoption, yet. Like Moore, Suh says more research is needed. While the interim six-month results show promise in safety and short-term control, “the small sample, lack of controls, and brief follow-up limit strong conclusions. Longer-term data are needed.”
The AFFINITY trial reached the 12-month follow-up time point, and the company is analyzing the data for publication, Pua says.
— Beth W. Orenstein of Northampton, Pennsylvania, is a freelance medical writer and regular contributor to Radiology Today.
