Karolyn Hopfensperger

Karolyn Hopfensperger, PhD

Clinical Assistant Professor

B2C432 University Hospital

1500 E Medical Center Dr.

Ann Arbor, MI 48109-5010


Administrative Contact


Dr. Hopfensperger received her PhD in Biomedical Engineering at the University of Iowa. She completed her Therapeutic Medical Physics residency at Huntsman Cancer Institute at the University of Iowa. She joined the Medical Physics faculty at Michigan Medicine in 2023.

Areas of Interest

  • Novel brachytherapy applicators and isotopes
  • Monte Carlo analysis
  • Out-of-field dose measurement
  • Clinical trials
  • Education and outreach


  • Certification: American Board of Radiology, Therapeutic Medical Physics, 2023
  • Residency: CAMPEP-Accredited Therapeutic Medical Physics Residency Program, Huntsman Cancer Institute, University of Utah, 2022
  • PhD: Biomedical Engineering, University of Iowa, 2020
  • BS:  Electrical Engineering, University of Wyoming, 2015

Published Articles or Reviews

Selected from 7 Publications

  1. Hopfensperger K.M., Li X., Paxton A., Sarkar V., Su F., Price R.G., Salter B.J., and St. James S. “Measurements of Fetal Dose with Mevion S250i Proton Therapy System with HYPERSCAN” J Appl Clin Med Phys. 2023;e13957.
  2. Adams Q., Hopfensperger K.M., Kim Y., Wu X., Flynn R.T. “169Yb-Based Rotating Shield Brachytherapy for Prostate Cancer” Med Phys. 2020 Dec;47(12):6430-6439.
  3. Hopfensperger K.M., Adams Q., Kim Y., Wu X., Xu W., Patwardhan K., Thammavong B., Flynn R.T. “Needle-Free Cervical Cancer Treatment Using Helical Multi-Shield Intracavitary Rotating Shield Brachytherapy with the 169Yb Isotope” Med Phys. 2020 May;47(5):2061-2071.
  4. Flynn R.T., Adams Q.E., Hopfensperger K.M., Wu X., Xu W., Kim Y. “Efficient 169Yb High-Dose-Rate Brachytherapy Source Production using Re-Activation” Med Phys. 2019 May 27;46(7):2935-2943.