ИСТИНА

ProtonVDA has developed a highly efficient and inexpensive proton tomography system based on solid state photomultipliers and fiber detectors [1] (fig. 1). One of the main advantages of this system is a lower, compared with similar X-ray imaging systems, equivalent dose that is received by the patient. This feature is explained by the accurate reconstruction of the tracks of individual protons passing through the patient’s body, as well as by using a special mode of operation of the accelerator with extremely low intensity of the extracted proton beam during the entire tomogra-phy time. The purpose of this work is to show the possibility of using the developed proton tomography system as part of the Russian proton therapy complex (PTC) «Prometheus» [2,3,4], which has been working in clinical mode for more than 3 years. This complex based on a synchrotron capable of accelerating protons to an energy up to 330 MeV (fig. 2). This fact makes proton tomography of entire patient body possible. The use of a synchrotron will significantly simplify the design of the scanner, and makes it cheaper. A special tomographic accelerator operation mode was developed and tested. It will increase the percentage of useful proton events registration that are used for further proton track recon-struction. This mode will increase the efficiency of the tomography setup and reducing the dose. The report presents the results of the first testing of the tomographic beam extraction mode at the PTC «Prometheus» synchrotron (fig. 2); examples of reconstructed proton scanner tomograms for physical objects and tissue-equivalent phantoms in case of irradiation with a proton cyclotron beam.