Patent ID: 8497480

Claim:
A particle radiotherapy apparatus comprising a detector ring with an annular arrangement of radiation detectors that are formed by laminating, in one direction, a scintillator with a plane of incidence for receiving radiation and converting the radiation into fluorescence, a light guide for receiving and transmitting the fluorescence, and a photodetector for detecting the fluorescence, and comprising, in addition thereto, an elongated top board inserted in an opening of the detector ring, and a particle beam emitting device for emitting a particle beam, the particle radiotherapy apparatus further comprising: a first ring having a central axis corresponding to a predetermined axis parallel to a direction of extension of the top board; a second ring having a central axis corresponding to the predetermined axis; a ring rotating device for rotating the first ring and the second ring about the predetermined axis; and a ring rotation control device for controlling the ring rotating device; wherein one end of the detector ring is supported by the first ring; the detector ring is tilted relative to the first ring, and extends from the one end toward the second ring, traversing the top board; the other end of the detector ring is supported by the second ring; and the detector ring makes rotating movement relative to the top board, in a state of being tilted relative to the first ring, with rotation of the first ring and the second ring.