Dr. J. Isabelle Choi

J. Isabelle Choi, MD, is a radiation oncologist with specialized expertise in the treatment of early-stage, locally advanced, and recurrent breast cancer. She practices at the intersection of advanced radiation technology and personalized cancer care, utilizing highly conformal photon therapy techniques and pencil beam scanning proton therapy in her clinical work. Her proficiency in proton therapy enables her to identify patients who stand to benefit from this precise form of external beam radiation, which delivers targeted doses to tumors while sparing surrounding healthy tissue. Dr. Choi's path to oncology was shaped by a personal experience with a family member's cancer diagnosis, which deepened her commitment to supporting patients through one of the most difficult chapters of their lives and inspired her to pursue a career in radiation oncology.

Dr. Choi's research is focused on reducing treatment-related side effects, refining radiation delivery techniques for breast cancer, and identifying optimal salvage strategies for recurrent disease. She serves as principal investigator of a national, multicenter, prospective randomized trial examining a shorter proton therapy regimen for breast cancer patients, and leads an institutional prospective clinical trial studying outcomes of repeat radiation therapy for patients with recurrent or new primary cancers. Her work carries significant implications for how proton therapy can be applied across a range of breast cancer presentations, with a strong emphasis on outcomes that matter to patients.

Across her national and international leadership roles, Dr. Choi chairs or co-chairs breast cancer committees at the American Radium Society, Proton Collaborative Group, Particle Therapy Co-Operative Group, and American College of Radiation Oncology, advancing radiotherapy education and research on a broad scale. In her clinical practice, she brings an empathetic, holistic approach to care, collaborating with multidisciplinary oncology teams to develop evidence-based treatment plans tailored to each patient's individual priorities and circumstances. Her combined dedication to clinical innovation, patient-centered care, and leadership continues to shape the evolving standards of radiation therapy for breast cancer.