Current Residents
Class of 2025
David Arsanious, MD
I grew up in Toledo, OH, and received my undergraduate degree from The Ohio State University where I majored in Molecular Genetics. After graduating, I moved to Burlington, VT to attend medical school at the Robert Larner, M.D. College of Medicine at the University of Vermont. Following medical school, I completed two years of Neurosurgery residency before deciding to change my specialty and enter the Radiation Oncology residency program at Penn. During my time in Neurosurgery, my research focused on Gamma Knife Radiosurgery for arteriovenous malformations, neurofibromatosis type 2-associated meningiomas, and glioblastoma. In my free time, I enjoy traveling, photography, and discovering new foods.
Monica Chelius, MD
I grew up in the greater Philadelphia area and received my undergraduate degree from Duke University, where I majored in Evolutionary Biology, minored in music, and was a die hard Duke Basketball fan. After graduation I worked as a research associate in MSKCC’s radiation oncology department on the lymphoma service. Working with this team spurred my interest in radiation oncology, where I worked on a range of projects including toxicity and outcomes analyses of very low dose radiation in indolent lymphomas, Langerhan's Cell Histiocytosis, and NK/T-cell lymphoma.
I then moved to Hanover N.H. and received my M.D. from Dartmouth. Prior to joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. Outside of the hospital, I enjoy hiking with my husband and our husky (Rio), skiing, trying out new recipes and inviting any family and friends over who are willing to try them.
Michelle Iocolano, MD
Chief Resident
I grew up in Queens, New York, and received my undergraduate degree in Psychology from the State University of New York at Geneseo. I then completed a Masters's degree in Psychology at the New School for Social Research. Following graduate school, I joined the Department of Psychology and Behavioral Sciences at Memorial Sloan Kettering Cancer Center (MSKCC), where I investigated methods by which various media and technology can be utilized to improve quality of life during and after cancer treatment. I then enrolled in the Stony Brook School of Medicine during which time I completed a research fellowship at MSKCC studying outcomes of postoperative radiation treatment on patients with locally advanced non-small-cell lung cancer. Prior to joining Penn’s Radiation Oncology Department, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. I have an interest in clinical trial development, locally advanced non-small cell lung cancer and novel applications of virtual reality to improve the patient experience. Outside of work, I enjoy trying new restaurants and spending time with my husband and our greyhounds, Norman and Charlie.
Cecilia Jiang, MD
I grew up in Edison, NJ, and later attended the University of Chicago, where I studied Biological Sciences. Afterward, I spent a year working as a hospitalist scribe at home before venturing south to Emory University School of Medicine. During that time, I was involved in clinical research projects on radiation treatment outcomes in prostate cancer, metastatic melanoma, and pancreatic cancer. Before joining Penn's Radiation Oncology Department, I completed my internship year at the Hospital of the University of Pennsylvania. Outside of work, I enjoy picnicking at the park, trying croissants from local bakeries, and visiting used bookstores.
Emily MacDuffie, MD
I was born in Ambler, Pennsylvania but grew up in beautiful Cape Elizabeth, Maine. I returned to Pennsylvania to attend Swarthmore College where I majored in Biology. Prior to attending medical school at Brown University, I lived in Botswana studying cervical cancer in patients with HIV as well as worked in a lab focusing on growth signaling in ovarian cancer. I continued these interests through medical school, dedicating a year as a Howard Hughes Medical Institute fellow to explore the impact of aneuploidy on oncogenesis. I completed my internship in the Department of Medicine at the Hospital of the University of Pennsylvania before joining the Department of Radiation Oncology. My academic interests include global oncology, virally-associated cancers, and palliative radiation. Outside of work, I enjoy running in the Wissahickon with my dog Bea, baking treats for friends and colleagues, and exploring Philly’s fantastic food scene with my husband.
Class of 2026
Zayne Belal, MD
I grew up in Baytown, TX and later attended the University of Southern California where I played Water Polo and finished a Degree in Social Sciences & Economics. I returned to Texas and completed another degree in Physics (emphasis in Health Physics) at Texas Southern University (TSU). During my time at TSU, I completed a summer internship at PENN in the Radiation Physics Department where we studied Proton beam characteristics using acoustic measurements. Following Graduation, I worked as a research assistant at MD Anderson Cancer Center in the Radiation Physics Department where we investigated radiation induced lymphopenia. I then completed medical school at Texas Tech University Health Sciences Center in Lubbock, TX. Before Joining Penn’s Radiation Oncology Department, I completed my internship year at the Hospital of the University of Pennsylvania. Outside of work, I enjoy grilling with friends and family, Movies/TV, and exploring Philadelphia’s wonderful food scene.
Cole Friedes, MD
Chief Resident
I grew up in Jacksonville, FL and received my undergraduate degree from Florida State University, where I studied biochemistry. I then pursued my medical degree at the University of Central Florida, in sunny Orlando. During medical school I spent a dedicated year of research with the Thoracic Department of Radiation Oncology at the Johns Hopkins School of Medicine. During that time I focused on the role of local ablative therapies in the treatment of oligoprogressive and oligometastatic lung cancers and mitigating patient reported financial toxicity. Prior to joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. My research interests include prospective clinical trials, thoracic malignancies, and treatment of low-volume metastatic disease. When not at work you can find me playing chess, exploring the fantastic Philly restaurant scene, learning about wine, cooking, playing disc golf, and relaxing with my wife.
Casey Hollawell, MD
I'm originally from Orefield, PA, a small town about an hour and a half north of Philadelphia. I stayed fairly local for college at Lehigh University where I studied biology and minored in business. I moved to Philadelphia after graduating college for a post-bac program at Temple University School of Medicine, where I then stayed for the following four years for Medical School. During that time, I began research in radiation oncology, primarily focusing on hypofractionation in the treatment of retroperitoneal sarcomas. I was able to work with my mentor in clinic as well and fell in love with the specialty. Prior to joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. Outside of the hospital, I love trying new restaurants within Philadelphia's abundant food scene, traveling (mostly to try new food!), and trying new exercise classes.
Abigail Pepin, MD
I grew up in Colorado and completed my undergraduate training at George Washington University, where I majored in Chemistry and Environmental Studies. During undergrad, I worked in a medicinal chemistry lab to develop novel agents to combat tuberculosis and malaria. After graduation, I enrolled in the George Washington University School of Medicine and Health Sciences. While living in Washington, D.C., I worked with the Georgetown University Department of Radiation Medicine on a number of projects investigating toxicity and quality of life in men undergoing radiation therapy for treatment of their prostate cancer. Prior to starting Radiation Oncology training, I completed my intern year in Internal Medicine at the Hospital of the University of Pennsylvania. My academic interests include patient-reported outcomes and quality of life metrics, palliative radiation, and hereditary cancers. In my free time, I enjoy travelling, skiing, spending time with my cat, cooking, and binging Netflix shows.
Class of 2027
Jonathan Baron, MD
I was born and raised in Hidalgo, Mexico and moved to Green Bay, Wisconsin for high school. I received my undergraduate degree from Princeton University, where I studied molecular biology. I then pursued my medical degree at the University of Pennsylvania. During my time in medical school, I became involved in radiation oncology research with the lymphoma research team. I was involved in projects that explored the role of bridging radiation before CAR-T cell therapy and the role of low dose radiotherapy for orbital lymphomas. Prior to joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. When not at work you can find me playing and watching soccer, listening to reggaetón, exploring the Philly food scene, and watching movies/ TV shows with my wife.
Melanie Berger, MD
I grew up between Baltimore and Washington D.C. in Clarksville, Maryland. I then moved to Williamsburg, Virginia and studied Chemistry at the College of William & Mary. After college, I returned to Maryland and spent a year working as an emergency medicine scribe before beginning medical school at the University of Maryland School of Medicine (UMSOM). While at UMSOM, I found the field of radiation oncology and conducted clinical research projects on gynecologic brachytherapy and esophageal cancer outcomes. Outside of the hospital, I enjoy attending local trivia nights, starting (and usually finishing) new knitting and crochet projects, playing intramural softball, and running along the Schuylkill.
Ian Messing, MD
I grew up in Miami, FL and followed a nontraditional path to medicine. I received my undergraduate and Master's degrees in finance and accounting from the University of Miami. My first career was in Public Accounting, focused on international taxation and merger and acquisition tax planning. After a change of heart I decided to pursue a career in medicine. I enrolled in a Post-Baccalaureate program at the University of Miami, followed by a medical degree at the George Washington University School of Medicine and Health Sciences in Washington, DC. I completed my internship in the Department of Medicine at the Hospital of the University of Pennsylvania before joining the Department of Radiation Oncology. My academic interests include health economics, palliative radiation, and patient-reported quality of life metrics and outcomes. During my free time I enjoy running, golfing, exploring new restaurants, rooting for the University of Miami Hurricanes, and playing with my two cats, Fennel and Chai.
Matthew Riina, MD
I grew up in Trumbull, CT and received my undergraduate degree from Northeastern University where I majored in Behavioral Neuroscience and had the opportunity to conduct drug discovery and development research with Moderna Therapeutics and the Dana-Farber Cancer Institute. I remained with my lab at DFCI for a year after graduation, focusing on developing cytometry-based assays to characterize the effects of novel cancer immunotherapeutics. I then went on to obtain my medical degree from Tufts University School of Medicine. Prior to joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. When not at work you can find me spending time with family, grilling, golfing, or embarking on an overly ambitious DIY project.
Class of 2028
Lauren Linkowski, MD
I grew up in Pittsburgh, PA, and received my undergraduate degree at the University of Georgia (go dawgs!), where I studied Nutritional Sciences. Later, I moved south to attend medical school at the University of South Florida in Tampa. I was connected with Moffitt Cancer Center and the Department of Radiation Oncology at USF. Through Moffitt, I found wonderful faculty members who inspired my love for the field and supported my variety of interests. With these mentors, I spent time researching MR-guided radiation therapy and trimodal therapy for muscle-invasive bladder cancer. Before joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. Outside the hospital, I love trying new workout classes with friends, reading for my book club, and spending too much money on Philly's coffee and bakery scene.
Hefei Liu, MD
I was ten years old when I immigrated to Philadelphia, PA, and grew up here for most of my life. As an undergrad, I graduated from Villanova University with a degree in Chemistry. Then, I attended medical school at the Medical College of Wisconsin in Milwaukee, where I completed a Master’s Degree in Clinical and Translational Sciences in addition to my medical degree. During my time in medical school, I also briefly worked at Varian Medical Systems, exploring artificial intelligence and emerging new technologies in radiation oncology, where my research interests lie. Before starting my radiation oncology residency here, I completed an internship in internal medicine at the University of Pennsylvania Hospital. Outside work, I love playing tennis, pickleball, golf, hanging out with my significant other, traveling, discovering restaurants, and getting better at guitar and ukulele.
Sidharth Ramesh, MD
I was born and raised in Minneapolis, MN. I made a brief pit stop at Penn studying biology before completing the remainder of my undergraduate and medical education at the University of Missouri - Kansas City, ultimately returning to Penn to begin radiation oncology residency. I initially found the field when I spent a summer as a research intern in Moffitt Cancer Center’s Department of Integrated Mathematical Oncology in Tampa Bay, FL, modeling NSCLC response to alternative XRT fractionation schedules. Before joining the Department of Radiation Oncology, I completed an internship in Internal Medicine at the Hospital of the University of Pennsylvania. Outside work, I enjoy standup comedy, supporting Minnesota sports teams, watching the English Premier League, and playing pickleball.
Avinash Ramkissoon, MD
I grew up outside of Toronto, Canada in a household with two brothers. I studied Chemical Biology during undergrad, then completed a master's degree in public health. Before medicine, I worked as an epidemiologist for Cancer Care Ontario investigating radon exposure and cancer incidence rates, which sparked an interest in learning more about cancer and how we use radiation in medicine. I moved to Detroit for medical school at Wayne State University, and then matched to Hospital of the University of Pennsylvania for Radiation Oncology residency. Prior to joining the Department of Radiation Oncology, I completed an intern year with the Department of Internal Medicine at the Hospital of the University of Pennsylvania. Outside of the hospital, I enjoy spending time with my wife exploring Philadelphia's cafes and bars, cooking, cycling, restoring vintage cars, and playing board games.
Michael Schad, MD
I grew up in Toronto, Canada, and moved to the US after high school, where I completed my bachelor's in mechanical engineering at the University of Virginia. While working as an engineer post-graduation, a few influential experiences pivoted my career from engineering to medicine. Along the way, I worked at the University of Virginia Department of Radiation Oncology as a research assistant, focusing on genitourinary and gynecologic malignancies. I also worked for a startup company helping to design and bring to market a new vaginal brachytherapy packing system, BrachyGelTM. I then completed my medical degree at the University of Pittsburgh School of Medicine, where I continued much of my prior research. Before joining the Department of Radiation of Oncology, I completed an internal medicine internship at the University of Pennsylvania Hospital. Outside of medicine, I enjoy spending time with my wife and daughter, running, exploring Philly neighborhoods, trying new foods, and watching shows.