A graduate of the University of Washington, Dr. Ahn attended medical school at the New York University School of Medicine and did his residency at UCLA Medical Center. He is board certified in therapeutic radiology with a particular interest in stereotactic radiosurgery for brain tumors and head and neck cancers. In addition, he has significant experience in MammoSite brachytherapy for early stage breast cancer. Dr. Ahn initiated the first MammoSite treatment in Ventura County in 2004. The breast brachytherapy in Thousand Oaks is now the largest in Ventura, Santa Barbara, and San Luis Obispo counties. He has published on stereotactic radiosurgery and was the recipient of the Young Oncologist Research Award 2003 from the American Radium Society. Dr. Ahn is based in the Westlake Village/Thousand Oaks centers and is co-medical director of the Los Robles Gamma Knife Center in Thousand Oaks.  Dr. Ahn is a member of the American Society for Therapeutic Radiology and Oncology (ASTRO), Los Angeles Radiological Society, American Radium Society, American Society of Clinical Oncology, and the American Society of Clinical Oncology (ASCO).

Dr. Ahn practices at the Westlake Radiation Oncology Medical Center.