How to cite: Rabin Y. “Back to the Future: Cryotherapy for Focal Prostate Cancer Ablation.” Grand Rounds in Urology. October, 2025. Accessed Apr 2026. https://grandroundsinurology.com/back-to-the-future-cryotherapy-for-focal-prostate-cancer-ablation/
Summary
Yoed Rabin, MS, DSc, Professor of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, introduces cryotherapy as a century-old cancer treatment that enters its modern era with the invention of the first cryostat in 1961. He describes the “dark ages” of the 1970s and 1980s, when complications were common due to limited imaging and control. A renaissance began in the 1990s with the introduction of ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) guidance, as well as the first regulatory clearance for prostate cryosurgery. Over the past thirty-five years, his group has developed computational tools for modeling, simulation, and planning that now converge with artificial intelligence and machine learning.
He uses Moore’s Law to illustrate that computational power has increased by a factor of five orders of magnitude since the early development of cryodevices. This expansion enables real-time organ reconstruction, image fusion, thermal prediction, and robotic guidance, yet clinical practice uses only a fraction of what current computation allows.
He outlines the anatomical and thermal challenges of cryotherapy, including understanding target geometry, interpreting two-dimensional ultrasound in a three-dimensional space, predicting freezing fronts, and adjusting cryoprobe power. Tools developed in his laboratory include heat transfer simulations, physical and imaging simulators, surgical operation simulators, and intelligent planning algorithms that determine probe placement and thermal protocols.
A central concept is the defect region, defined as the mismatch between the desired target volume and the achieved lethal isotherm, typically at a temperature of approximately twenty degrees Celsius. The defect region cannot be eliminated, but it can guide procedure termination, comparison of cryoprobe layouts, optimization of thermal protocols, automated planning, and training of machine learning models.
Dr. Rabin describes a computerized cryotherapy trainer that improves planning accuracy in both surgical residents and engineering students after ninety minutes of interactive simulation. He highlights future directions, such as cryoprobe miniaturization, device scale-down, robotic cryosurgery, real-time thermal feedback, and artificial intelligence markup language (AIML)-driven planning.
Frontiers in Oncologic Prostate Care and Ablative Local Therapy (FOCAL) is an outstanding program on prostate imaging, transperineal interventions, and ablative treatments for prostate cancer and benign prostatic hyperplasia. Bringing together community-based, academic, and industry partners, FOCAL offers lectures by world-renowned faculty and hands-on training workshops on in-office transperineal interventions, fusion-guided prostate ablation and state-of-the-art BPH management with novel technologies.
ABOUT THE AUTHOR
Yoed Rabin, MS, DSc, is a Professor of Mechanical Engineering at Carnegie Mellon University in Pittsburgh, Pennsylvania. Dr. Rabin has a broad range of research interests including, areas of energy modalities in biology and medicine, including cryopreservation, cryosurgery, hyperthermia, thermal regulation of the human body, blood flow, and medical imaging.
Dr. Rabin earned his BS and MS from Ben-Gurion University in Israel. He then earned his DSc in Mechanical Engineering at the Israel Institute of Technology in Haifa. Dr. Rabin has been affiliated with a wide variety of industrial companies over the years, working on a broad range of thermal engineering applications. He has authored and co-authored over 200 publications.
