PROBLEM TO BE SOLVED: To suppress the distortion of a pixel (voxel) and acquire an axial cross-sectional image with high image quality to thereby improve the accuracy of positioning and monitoring of a subject in radiotherapy.SOLUTION: Provided is a radiotherapy system, comprising: a therapeutic irradiation unit 22 mounted on a therapeutic rotation mechanism 21 and irradiating a target 110 of a subject 1 with therapeutic radiation while rotating about the subject an X-ray source 12 mounted on an X-ray source rotation mechanism 11 and irradiating the target with a monitoring X ray while rotating about the subject and a detector 13 mounted on a detector rotation mechanism and detecting the X ray which is projected from the X-ray source and transmitted through the subject while rotating about the subject in synchronization with the X-ray source rotation mechanism. In the radiotherapy system, the X-ray source and the detector rotate on a rotation axis P common therebetween, and the therapeutic rotation mechanism, the X-ray source rotation mechanism, and the detector rotation mechanism are arranged such that the rotation planes of the therapeutic irradiation unit, X-ray source, and detector are different from one another and do not interfere with one another.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2018,JPO&INPIT【課題】画素(ボクセル)の歪を抑制し、高画質のアキシャル断面像を取得して、放射線治療における被検体の位置決め、監視精度を向上させる。【解決手段】治療用回転機構21に配置され、被検体1の周囲を回転しながら被検体の標的110に治療用放射線を照射する治療用放射線照射部22と、X線源用回転機構11に配置され、被検体の周囲を回転しながら標的にモニタリング用X線を照射するX線源12と、検出器用回転機構に配置され、X線源用回転機構に同期して被検体の周囲を回転しながらX線源から照射され被検体を透過したX線を検出する検出器13と、X線源及び検出器が共通の回転軸Pを中心に回転し、且つ、治療用放射線照射部、X線源及び検出器の各回転面がそれぞれ異なり、互いに干渉しないように治療用回転機構、X線源回転機構及び検出器用回転機構が配置されている放射線治療システムを提供する。【選択図】図2
