The JINR Long-Term Development Strategic Plan up to 2030 involves the creation of the innovative centre for experimental and clinical research in proton therapy. The proton medical cyclotron MSC-230 will be the basic facility of the centre. Development of methods, technologies, modes of planning and conducting radiation therapy is underway at the Dzhelepov Laboratory of Nuclear Problems. Specialists also discuss the location of the future accelerator.

On 30 March, at the seminar “Development prospects for proton radiotherapy at DLNP JINR”, a researcher of the Scientific and Profit Division “Phasotron Department”, Candidate of Technical Sciences Alexey Agapov spoke about the state-of-the-art at the DLNP Medical-Technical Complex and considered the possibility of implementing a number of irradiation methods in the planned centre.

JINR MTC has developed a number of such methods. 3D conformal proton radiation therapy, which was used for cancer patient treatment from 2000 to 2019, is one of them. According to the speaker, the method is the best possible prototype of flash therapy – an irradiation method – at the future accelerator. An experimental test of dynamic irradiation was conducted at MTC. It is also possible to implement this technique at the MSC-230. Moreover, it is proposed to use a scanning method widely used in the world but not at MTC.

JINR pays special attention to the study of the innovative flash therapy method. The specific feature of this method is that a tumour is irradiated with ultra-high dose rates during milliseconds, leaving the surrounding healthy tissues minimally affected, unlike slower methods of irradiation. Scientists have been studying a flash therapy method at MTC since 2020. During this time, specialists have developed a radiation stand for biological object irradiation. A proton beam with the intensity of up to 70 Gy/s was obtained. It was used to irradiate a hundred of experimental mice and cell cultures in a flash mode and to create a plane parallel monitor ionisation chamber.

The creation of the innovative centre for applied research in proton therapy is a broad project that involves several laboratories of the Institute. The basic facility of the new centre will be the superconducting isochronous cyclotron MSC-230 with a proton beam of the maximum energy of 230 MeV. This energy is most suitable for proton therapy. The accelerator will be compact:3.5 m in diameter and 1.7 m in height. It will have a small magnet weight compared to its analogues. The maximum beam current will be up to 10 μA.

Such parameters will allow obtaining a dose rate of about 100 Gy/s. “Such a reverse in intensity will allow us to conduct various experiments, including the study of the flash effect,” Alexey Agapov noted.

In the photo: a researcher of the Scientific and Profit Division “Phasotron Department” Candidate of Technical Sciences A. V. Agapov

Employees of JINR MTC suggest that the best option for the proton accelerator is to be located in a separate building. The design project of the building has already been prepared for approval. In particular, the project includes a room for the preparation and storage of radiobiological preparations and two treatment booths. The first one is for research on radiobiology and proton therapy using the standard and dynamic irradiation method. The second one is for an active irradiation method without a rotary magnetic system (gantry). As long as there is no separate building, specialists are going to assemble, locate, and test the accelerator in the building No. 5 of DLNP.

As part of the project on the creation of the new proton accelerator MSC-230, new technologies are being developed at DLNP JINR. Specialists of the Laboratory have developed a method for changing the energy of the directional proton beam inside the cyclotron. This technique can change the energy of a proton beam used for flash therapy. Moreover, the task of a multiple increase in the performance of the medical proton cyclotron MSC-230 has been solved. This invention continues the idea protected by the previous patent “Device for resonance charge of capacitor”. The Federal Service for Intellectual Property (Rospatent) recognised it as one of the 100 best inventions of Russia for the second half of 2020.

JINR specialists prepared the technical design of the 230 MeV Medical Superconducting Cyclotron at the end of 2021. JINR plans to create such an accelerator in each Member State.