Radiotherapy system

Abstract

A radiotherapy system achieves highly-accurate respiratory-gated irradiation with less x-ray exposure by performing x-ray imaging only during the respiratory phases that are necessary for the respiratory-gated irradiation. An external respiration monitor 300 externally monitors an external respiratory index of a patient. An x-ray source 200 and an x-ray detector 210, or internal-respiration observation devices, acquire x-ray images of the patient and monitor an internal respiratory index of the patient using the positions of internal body structures indicated by the acquired x-ray images. An x-ray imaging gating device 310 gates the x-ray imaging performed by the internal-respiration observation devices with the use of the external respiratory index such that the x-ray imaging is performed while the external respiratory index is within a predetermined range. An irradiation gating device 410 gates the irradiation of a treatment beam with the use of the internal respiratory index.

Dependencies are inferred from the claim text.