Even though systemic anti-tumor responses from local radiotherapy alone (abscopal responses) remain rare, it is widely recognized that ionizing radiation modulates the immune response in a variety of ways, (see Figure above). Approaches combining immunotherapy (mostly checkpoint inhibitors) and radiation are now in clinical trial stage for a number of disease sites.

Our lab develops and applies methodologies to approach a wide range of highly relevant clinical questions:

  • How does the optimal radiation regimen (sequencing / dose / fractionation) differ depending on the immunotherapeutic approach used? (see Figure above)
  • How patient-specific is the interaction? How can we assess the state of the immune system in a patient and guide optimal treatment combinations? (see Figure below)
  • Does proton therapy affect the immune response in a different way from conventional photon irradiation?

 Project Opportunities: If you’re interested in working on these or related questions, have a look at our list of open projects --> here

Team members involved in this effort:

Abdelkhalek Hammi, PhD

Wonmo Sung, PhD


RT - Immune - Tumor Model incorporating the main interactions


Simulating impact of fractionation on lymphocyte depletion and recovery


  1. Abdelkhalek H, Paganetti H and Grassberger C “Four-dimensional Blood Flow Model for Dose Calculation to Circulating Blood and Lymphocytes” Physics in Medicine and Biology 2020, in press.
  2. Sung W, Grassberger C, et al. “A Tumor-Immune Interaction Model for Hepatocellular Carcinoma based on measured Lymphocyte Counts of Patients undergoing Radiotherapy” International Journal of Radiation Oncology* Biology* Physics 105.1 (2019): S5, ASTRO abstract, Winner best translational abstract, paper under review
  3. Grassberger C et al. "Differential Association Between Circulating Lymphocyte Populations With Outcome After Radiation Therapy in Subtypes of Liver Cancer." International Journal of Radiation Oncology* Biology* Physics 101.5 (2018): 1222-1225.
  4. Grassberger C et al. "Circulating Lymphocyte Counts Early During Radiotherapy are Independently Predictive of Recurrence in Pediatric Medulloblastoma” International Journal of Radiation Oncology* Biology* Physics 105.1 (2019): S177-S178, ASTRO abstract, paper under review