Abstract: The present relates to device for ultra-high dose rate radiation treatment to a patient, comprising: —a radiation source for providing a radiation beam, and —a linear accelerator for accelerating said radiation beam until a predetermined energy, and —a beam delivery module for delivery the accelerated radiation beam. The device is arranged for generating an accelerated radiation beam having a predetermined energy between about 50 MeV and about 250 MeV, to deliver rate radiation dose of at least 10 Gy, during an overall time less than about 200 ms in order to generate a radiation field for treating a target volume of at least about 30 cm3, with said ultra-high dose rate radiation dose and/or a target volume located at least about 5 cm deep in the tissue of the patient with said ultra-high dose rate radiation dose.