Abstract: The invention provides a radiotherapeutical or radiosurgical system comprising at least two high-intensity radiation sources configured to rotate around a common rotation axis and a ring-shaped imaging device. A three-source configuration is considered as the most cost-effective and will be used as an example for illustration. The configuration of these high-intensity radiation sources and use of a unique compact MLC for each of the radiation sources make it possible for the system to rapidly deliver high-conformal non-coplanar stereotactic radiation treatment in one gantry rotation without any couch rotation. Therefore the invention can deliver high precision and high-conformal non-coplanar stereotactic radiation treatment to any part of the body in an extremely short time (0.1-20 seconds), which may exhibit numerous advantages over the prior art, such as reduction of radiation damage to the circulating immune cells in blood and mitigation of patient motion-induced problems, among others.