Prof. Valentin Djonov MD University of Berne, Switzerland The main scientific interest of Valentin Djonov’s group is the radio-biological effects induced by Microbeam Radiation Therapy (MRT). MRT is a preclinical radiotherapy technique using spatially fractionated X-rays to produce alternating regions of high and low dose deposition in the target tissue. This results in unique radiation/tissue interactions that expands the therapeutic index of radiation therapy by increasing tumor control, including that of radioresistant malignancies, while simultaneously exhibiting remarkable normal tissue sparing even when delivering peak doses of hundreds of Grays. This "MRT effect" appears to be governed by a new radiobiological paradigm characterized by several novel mechanisms that contribute to treatment success: (i) MRT acts as a very potent angiodisruptive and anti-angiogenic agent resulting in reduced blood supply to irradiated tumors (ii) these disrupted tumor vessels serve as a gateway for circulating immune cells to invade MRT-irradiated tumor tissue, and enhance anti-tumor immune responses (iii) this MRT-induced immune effect is characterized by a specific gene signature that implicates myeloid cell recruitment and interferon responses as key mediators of this anti-tumor response. These unique features support the clinical translation of MRT as a novel therapeutic approach for the treatment of inoperable, radioresistant lesions.