Ryan C. Mueller, MD, BSRT(T)

Radiation Oncology

HSHS St. Elizabeth’s Radiation Oncology Center at Cancer Care Center of O’Fallon

Dr. Ryan Mueller, radiation oncologist, joined Cancer Care Specialists of Illinois in July 2026. He primarily sees patients at the Cancer Care Center of O’Fallon and Anderson Hospital Radiation Oncology Center in Maryville. He also provides occasional services in Decatur and Effingham.

Dr. Mueller received his Doctor of Medicine from Southern Illinois University School of Medicine in 2021. Prior to becoming a physician, he was a radiation therapist at Siteman Cancer Center and Mercy Hospital in the St. Louis area. Dr. Mueller completed his internship at SIU School of Medicine and Springfield Memorial Hospital in Springfield, Illinois. He went on to complete his radiation oncology residency and served as the liaison for medical student education in radiation oncology at Washington University School of Medicine/Barnes-Jewish Hospital/St. Louis Children’s Hospital Consortium in St. Louis, Missouri.

Dr. Mueller has received several awards, including the Edward Mallinckrodt Award of Excellence, and has co-authored several publications on locally advanced non-small cell lung cancer, prostate cancer and bladder cancer. He gave a featured poster presentation at the ASTRO Annual Meeting in Washington, DC, in 2024 on Dosimetric Impact of Online Adaptive Radiotherapy on a Phase II Study of Hypofractionated Concurrent Chemoradiation for Locally Advanced Non-Small Cell Lung Cancer.

Dr. Mueller is board certified in Radiation Oncology. He has specialized skills in radiotherapy techniques, including 3D conformal radiation therapy, IMRT/VMAT, SRS/SBRT, Brachytherapy and Radiopharmaceuticals. He also holds membership in the American Society for Radiation Oncology (ASTRO), American College of Radiation Oncology (ACRO) and American College of Radiology (ACR). In his free time, he enjoys hunting, fishing, playing golf and soccer, and spending time with his family.

Radiation Oncology Residency
Washington University School of Medicine / Barnes-Jewish Hospital / St. Louis Children’s Hospital Consortium in St. Louis, MO, 2026

Internal Medicine Residency
SIU Medicine, Springfield Memorial Hospital, Springfield, IL, 2022

Education
Washington University Teaching Physician Pathway Clinician Educator Certificate, Washington University School of Medicine, 2025
M.D., Southern Illinois University School of Medicine, Springfield, IL, 2021
Certificate in Medical Spanish, Southern Illinois University-Carbondale, Carbondale, IL 2019
B.S., Radiation Therapy, Saint Louis University, St. Louis, MO, 2012

Certifications
Radiation Oncology – American Board of Radiology

Memberships
American Society for Radiation Oncology
American College of Radiation Oncology
American College of Radiology
American Registry of Radiologic Technologists
American Society of Radiologic Technologists

Awards
Edward Mallinckrodt Award of Excellence, 2012
ASTRO Poster Presentation (WUSTL SOM), 2024

Hometown
Maeystown, IL