Abstract: A radiotherapy control apparatus includes a fluoroscopic image acquisition unit to acquire fluoroscopic images of markers in a patient from a single fluoroscopic imaging device, a projection line calculation unit to identify projected positions of the markers on the fluoroscopic image and calculate equations of projection lines linking these projected positions and a focus position of the imaging device, an inter-marker distance acquisition unit to acquire a distance between each pair of the markers, a marker position calculation unit to calculate current positions of the markers based on the equations and the distances, and a therapeutic radiation emission determination unit to determine whether to emit therapeutic radiation based on the current positions of the markers.

Abstract: [Problem to be Solved] To provide a radiotherapy control apparatus and radiotherapy control program capable of calculating the current positions of markers implanted in a patient by means of a single fluoroscopic imaging device and reducing a radiation exposure dose inflicted on the patient by radiographic radiation used for fluoroscopic observation during radiotherapy. [Solution] The present invention includes a fluoroscopic image acquisition unit 41 adapted to acquire a fluoroscopic image of three or more markers from a single fluoroscopic imaging device 12, a projection line calculation unit 38 adapted to calculate equations of respective projection lines, an inter-marker distance acquisition unit 42 adapted to acquire each distance between each pair of the markers, a marker position calculation unit 43 adapted to calculate current positions of the respective markers, and a therapeutic radiation emission determination unit 44 adapted to determine whether to emit therapeutic radiation.