Applying the x-ray, gamma-ray and the corpuscular ray to the affected part, changing the position of the aforementioned detector ring with the open die PET device and the radiation beam detector which includes the multiple detector rings which become with the shift possibility, multi ring in case of the beam monitoring in order to detect the annihilation radiation which it occurs at the time of radiation cancer remedying which it does, with radiation lighting, shift die radiotherapy PET compound device which has with the lighting possible radiation lighting device from between the aforementioned detector rings, after irradiating the radiation beam from between the detector rings, it does radiation measurement.X線、ガンマ線や粒子線を患部に照射して行う放射線がん治療において、放射線照射によって生じる消滅放射線を検出するためのビームモニタリングに際して、シフト可能な、マルチリングでなる複数の検出器リングを含む開放型PET装置と、前記検出器リングの間から放射線ビームを照射可能な放射線照射装置とを備えた検出器シフト型放射線治療・PET複合装置により、前記検出器リングの位置を変えて、検出器リングの間から放射線ビームを照射した後、放射線計測を行なう。
