Experience of Proton Radiotherapy at the Joint Institute for Nuclear Research, Dubna

Abstract

First experiments on using proton beams for radiotherapy of malignant tumours at the 680 MeV proton synchrocyclotron of the V.P. Dzhelepov Laboratory of Nuclear Problems of the Joint Institute for Nuclear Research (DLNP JINR) have been initiated by Prof. V.P. Dzhelepov and were started in 1967. 28 patients with different types of superficially located malignancies, such as skin melanomas, metastases of cancer to peripheral nodes, larynx cancers and so on, were treated during the period of 1967–1971. Then the method of scanning rotation irradiation of deep-seated tumours was developed and started to use at DLNP JINR. 50 patients with esophagus cancer, larynx cancer and metastases of malignant tumors were treated with that technique. During the period of 1974–1984 the synchrocyclotron was modified to the Phasotron with the increase of output current. At the same time, a multi-room Medico-technical complex for hadron radiotherapy of cancer patients was constructed. It allows tumour treatment with wide and narrow horizontal beams of protons (70–660 MeV), negative pions (30–80 MeV), high-energy neutrons (mean energy 350 MeV), and with their combinations. The complex includes also the standard gamma-therapy unite Rokus-M with 60Co source for external irradiation. The unique equipment has been developed and constructed, including full-scale PET, X-ray CT for topometry of patients in sitting position, and proton CT. A new round of the development started in December 1999 when a specialized radiological department of patient capacity of 25 beds was opened in Dubna. Since 2000 regular sessions have been conducted in research of proton therapy efficiency in irradiation of patients with neoplasms located in the head, neck and other parts of the body. 1283 patients have received courses of radiotherapy at the Phasotron beams by the end of 2018. The technique of 3D conformal proton radiotherapy in which the maximum of the formed dose distribution conforms most accurately to the shape of the irradiated target has been realized and put into operation. In this way, the maximum sparing effect is achieved in normal tissues and organs surrounding the tumor. The statistical analysis of the proton treatment results of two classes of neoplasms treated with the JINR proton beam (arteriovenous malformation) of the brain and the skull base chordomas and chondrosarcomas) are presented. A new project of the development and construction of a modern superconducting cyclotron SC202 dedicated for proton radiotherapy was prepared recently by the staff of the DLNP JINR and Institute of Plasma Physics Chinese Academy of Sciences (Hefei, China). It is supposed that the accelerator will become the base of a new Proton Therapy Centre in Dubna. It will consist of two treatment rooms: the first one will be equipped with static wide horizontal proton beam and a therapeutic chair, and the second one is planned to provide with gantry for a pencil proton beam dynamic scanning and a positioner for supine patient position during irradiation.