Meeting Banner
Abstract #3422

MRI assessment of abscopal effect induced by radiation/immune checkpoint blockade combination therapy

Kota Yamashita1, Yasunori Otowa1, Kazutoshi Yamamoto1, Jeffery R. Brender1, Nallathamby Devasahayam1, Murali C. Krishna1, and Shun Kishimoto1
1Radiation Biology branch, National Cancer Institute, Bethesda, MD, United States


Radiation therapy (RT) occasionally induces regression of non-irradiated metastatic lesions, which is called abscopal effect. Immune checkpoint inhibitors enhance abscopal effects. In this study we examined the physiological changes induced by abscopal effect and identify using MRI-based imaging biomarkers which predict the successful abscopal effect. Hypoxic fraction < 10 mmHg (HF10), permeability, perfusion, and CD8+ T cell infiltration in unirradiated tumor increased after the combination of RT and PD-1 blockade therapy. Interestingly, higher permeability/perfusion and lower HF10 in irradiated tumor before treatment is associated with slower growth of the unirradiated tumor after treatment of the tumor on the contralateral side.

This abstract and the presentation materials are available to members only; a login is required.

Join Here