title: A simple isocenter checking procedure for radiotherapy treatment machines using the optical pointer.
abstract: Techniques are described for simple and convenient checks on the position and size of the isocenter of radiotherapy treatment machines by measuring the displacement of the optical pointer on a flat scale on the surface of the treatment couch.
mesh_terms: D006801:Humans; D008722:Methods; D010315:Particle Accelerators; D011785:Quality Assurance, Health Care; D011882:Radiotherapy, High-Energy / Q000295:instrumentation*