A radiation treatment system is described, including a linear accelerator (LINAC), having a housing, to emit a treatment beam to a target location and a Cerenkov emission detector, coupled to the housing of the LINAC, to capture a set of images of optical Cerenkov emission generated at the target location by charged particles of the treatment beam. A method is described including emitting the treatment beam from the LINAC to the target location and capturing, using the Cerenkov emission detector coupled to the LINAC, the set of images of optical Cerenkov emission generated at the target location by the treatment beam.
