Patent attributes
A method and apparatus for position detection, and a radiotherapy system are provided. The radiotherapy system includes: a treatment couch, a positioning apparatus, an optical tracking system and a computer; the positioning apparatus disposed on the treatment couch, and at least one reference point provided on the positioning apparatus; the optical tracking system disposed above the treatment couch and configured to detect relative positioning between a mark point set on a treated part of a patient and the reference point, determine deviation between the relative and reference positions, and send the deviation to the computer. The computer is configured to determine whether to adjust a position of the treatment couch based on the deviation and deviation range. The system provided by the present disclosure avoids the influence of patient movement on the accuracy of treatment, and prevents a treatment beam from damaging normal tissues of the patient.