T. Bortfeld: Colloquium / Physicists in Medicine - What We Do and Where We Are Going

After a general overview of the growing field of medical physics, I will describe my personal journey as a physicist in medicine. It started as a physics student working on computational de-blurring of microscopy images in the histopathology department of the German Cancer Research Center. As a Ph.D. student, I did some early work on what is now known as Intensity Modulated Radiation Therapy (IMRT), and later took IMRT from its early concepts to its widespread and practice-changing use today. For the remainder of my talk, I will describe the three current areas of focus in my research laboratory. First, we are developing physics-inspired models to inform the extent of the "clinical target volume" in cancer therapy, which is the area to be treated in combined modality treatments including surgery, radiation, and other modalities. Methods include differential geometry-based approaches and Eikonal equation solvers, as well as stochastic methods analogous to the Ising model. They also include deep learning methods for bypassing barrier structures. The second focus is "optimal stopping" in cancer treatment, which is a mathematical way to personalize treatment concepts based on Bayesian networks. Finally, the third focus area is the democratization of proton therapy, where we are developing more affordable and readily available proton therapy techniques. We will also touch on advanced proton/particle therapy concepts such as FLASH therapy and prompt gamma spectroscopy as well as ionizing radiation acoustic methods to determine the particle range in the patient. Dr. Bortfeld received his Ph.D. in Physics from the University of Heidelberg, Germany, in 1990. While working in medical physics at the German Cancer Research Center (DKFZ), he was instrumental in the early development of intensity-modulated radiation therapy (IMRT), including inverse planning algorithms and the delivery of IMRT with multileaf collimators (MLC). His work enabled the first clinical application of MLC-based IMRT at Memorial Sloan Kettering Cancer Center in New York in 1995. Since then, more than 30 million patients worldwide have been treated with these techniques. In 2001, Dr. Bortfeld was appointed Director of Physics Research in Radiation Oncology at Massachusetts General Hospital (MGH) in Boston, where he is now Chief of the Division of Radiation Biophysics and Andres Soriano Professor at Harvard Medical School. His current research interests include Temporal Optimization and Personalization of radiation therapy (TEMPO), the transformation of clinical target definition from an art to a science, and the democratization of proton therapy.