Reflecting on his more than 20 years as a member of the teaching faculty in the Department of Electrical and Computer Engineering (ECE) at the University of Wisconsin-Madison, Eric Hoffman is grateful for the opportunity he had to teach and advise countless undergraduate ECE students and proud to have been in a department with a vibrant applied research portfolio.
He’s especially thankful for cancer treatment technology developed by UW-Madison researchers, including ECE colleagues just a few doors down from his office in Engineering Hall.
Over the last 25 years, Daniel van der Weide, the Grainger Institute for Engineering Professor, Nader Behdad, the Harvey D. Spangler Professor, and Susan Hagness, former ECE Department Chair and the Philip Dunham Reed Emeritus Professor of Electrical and Computer Engineering and Maria Stuchly Professor Emeritus of Electrical Engineering, and other colleagues and students across the UW-Madison campus, including the School of Medicine and Public Health, have pioneered and refined elements of microwave ablation therapy, a technique in which a specialized, minimally invasive antenna or probe heats up and destroys tumors using microwave-frequency electromagnetic energy.
Ablation was one of Hoffman’s key treatments when in 2022 he was diagnosed with stage IV colon cancer, which had metastasized to his liver and lungs.
Hoffman
For nearly two years, Hoffman underwent an array of therapies to treat 24 tumor sites, including surgery, radiation and a type of chemotherapy called 5-FU, which was developed at UW-Madison. But the most frequent therapy was microwave ablation.
“I’d heard a couple of little stories about ECE’s work on ablation, but to be honest, that area of electrical engineering—electromagnetics—was always kind of a ‘black magic’ field to me. I focus on circuit design,” he says. “But my oncologist had actually worked with Susan and pointed out the connection, telling me how ECE had contributed significantly to the field.”
Although ablation therapy is now a routine part of cancer treatment, it took decades of innovation to mature the technique, which is still advancing. Radio-frequency ablation using medium-frequency electrical currents was first used in the 1990s to destroy certain small tumors.
Clinicians began asking for an energy source to treat larger tumors. Microwaves were a promising candidate. Among the considerations were determining the kinds of probes that could deliver the microwave energy to the tumor, how to limit damage to surrounding healthy tissue, and how to control the size and shape of the region of microwave power absorption, known as the ablation zone.
That’s why Fred Lee, a professor of radiology at UW-Madison, approached van der Weide for help in the early 2000s. Along with Chris Brace, then an electrical engineering graduate student and now a professor of radiology and biomedical engineering at UW-Madison, van der Weide drew on his background in ultrafast microwave measurement and near-field sensing to explore ways to precisely deliver controlled doses of microwave energy.
Brace, van der Weide, and other UW-Madison medical researchers developed new probe designs and control and imaging systems that could deliver microwaves directly to tumors without damaging the surrounding tissue. This work led to a Madison-based spinoff company called NeuWave; founded in 2008, it commercialized a next-generation microwave ablation platform quickly adopted by the oncology community.
In 2016, Ethicon, the surgical arm of Johnson & Johnson, acquired the company, which has delivered the UW-Madison-engineered technology to more than 100,000 patients worldwide. In 2026, French company Quantum Surgical acquired the brand, incorporating it into its AI and robotics-focused medical technologies.
Hagness and Behdad have also made major advances. Early on, researchers believed ablation could only be conducted with low-frequency microwaves using thicker-diameter antennas equipped with a device called a balun that prevents microwaves from damaging healthy tissue along the probe’s length. Through modeling and experimentation, however, Hagness and Behdad showed that high-frequency microwaves were effective for ablation and that innovations in antenna design could eliminate the need for the balun. Together, they and their students developed a new, ultrathin, flexible, balun-free probe. Importantly, the probe can thread through a blood vessel, allowing it to reach tumors in sensitive areas that rigid probes might damage.
UW-Madison researchers (left to right) Chris Brace in the Departments of Biomedical Engineering and Radiology, Paul Laeseke in Biomedical Engineering and Radiology, Daniel van der Weide in Electrical and Computer Engineering, and Fred Lee Jr., in Biomedical Engineering, Radiology, and Urology, founded Neuwave Medical, Inc., a company that produces equipment for microwave ablation therapy.
More recently, Hagness, ECE Assistant Professor Chu Ma, and their students have been developing a new approach for monitoring microwave ablation in real-time in place of CT or MRI. “These and related research activities have proven to be an outstanding training ground for our PhD students who graduate with a deep multi-physics background that is relevant not only to the healthcare industry but other cutting-edge technology sectors,” says Hagness. “For example, one of recent graduates is now at Los Alamos National Lab and another is at TypeOne Energy.”
Van der Weide thinks the cross-disciplinary work on ablation showcases applied research at its best. “Microwave ablation is a powerful example of how engineering at UW-Madison can move from fundamental theory to global clinical impact,” he says. “The pathway from lab to market was made possible by a culture of collaboration across engineering and medicine—and by a strong institutional commitment to real-world translation.”
Hagness, who recently took a position as dean of the engineering school at Case Western Reserve University, says the ablation project has been particularly gratifying. “To witness the translation of a new technology out of the lab and into the clinic, and in the process so dramatically impact the life of a colleague, has been extraordinarily meaningful to our community,” she says. “This is a shining example of the Wisconsin Idea.”
For Hoffman, that commitment made a real impact: Minimally invasive ablation reduced the risk of collateral damage to Hoffman’s heart when targeting a tumor on his lung. “With microwave ablation, my surgeons felt more confident that the damage could be kept under control,” he says.
If he had been diagnosed just five years earlier, Hoffman’s oncologist told him, he likely wouldn’t have survived. Now—due in part to UW-Madison advances in microwave ablation—Hoffman is not only cancer-free, but also newly retired and ready to head into the next chapter of his life.
“I’ve had chemo, of course, and radiation, and they’ve all been effective. But ablation has been the most frequently used technique on me,” he says. “And I’ve got to say, the results have been amazing.”
Top image: Ablation probes developed by NeuWave Medical Inc. Submitted photo.