Our primary research focus is the investigation of photodynamic therapy (PDT) for the treatment of solid malignancies. PDT involves the local illumination of tumors that have accumulated a photosensitizer following exogenous administration of the photosensitizer or its precursor.  The light-excited photosensitizer interacts with oxygen in the treated tissues (tumor) to produce reactive oxygen species that damage the tissue and its associated stroma, including the supporting vascular network.  Insomuch as oxygen is a substrate in the photochemical reactions initiated by PDT, it is both required for and consumed by PDT.   However, in addition to oxygen consumption by the photochemical process, impairment of oxygen delivery through PDT-created vascular damage, or the simultaneous occurrence of both of these processes can lead to the development of response-limiting hypoxia during therapy.  Our research is centered on defining the intratumor and intertumor distributions of microenvironmental factors essential to PDT, such as oxygenation, vascularization, perfusion, and photosensitizer concentration, toward the goal of identifying approaches to improve PDT response through manipulation of microenvironmental targets or physiological processes.   

Dr. Theresa Busch received her Ph.D. in Biophysics in the Roswell Park Cancer Institute Graduate Division, University of Buffalo, State University of NY (SUNY).   She completed a postdoctoral fellowship at the University of Pennsylvania, and she is presently a Research Assistant Professor in the Department of Radiation Oncology, School of Medicine, University of Pennsylvania.   Dr. Busch has performed extensive research on the biological effects of photodynamic therapy (PDT) on normal and malignant tissues.  Her particular research interests include the effects of PDT on tumor hypoxia and blood flow, as well as mechanisms of controlling PDT-created oxygen depletion toward the goal of improving treatment outcome. These interests extend to the clinic, where she has performed studies on photosensitizer uptake and the presence of hypoxia in the tumor and normal tissues of patients to receive PDT.  She has a long-standing publication record in these areas, including a number of invited works in the form of reviews, editorials or book chapters.   Furthermore, several of her publications have appeared as featured articles in the journals Cancer Research or Clinical Cancer Research.  In one recent manuscript (Clinical Cancer Research), Dr. Busch and her colleagues reported the results of one of the largest clinical studies to date on photosensitizer (Photofrin) levels in patient tissues.   In addition to leading an active translational research program in PDT, Dr. Busch served as the Director of the Radiation Oncology Research Seminar Series from 2001-2006. As the director of this series she invited and oversaw the visits of locally, nationally, and internationally renowned guest lecturers in radiation biology or related fields. Currently, she is the coordinator of Cancer Biology, a lecture series for medical residents in radiation oncology. She has mentored many students, ranging from undergraduate to medical level, in PDT-related research projects.  She also has served as a member of a special NIH study section assembled to review SBIR/STTR proposals (2002-2003), as well as an ad hoc member of Radiation Study Section.