Proton beam therapy complex at 1000 MeV proton beam

Synchrocyclotron SC 1000 with the proton energy of 1000 MeV based in Leningrad Nuclear Physics Institute was put into operation in 1970. As it turned out, it could be used not only in order to conduct research in field of fundamental physics, but also for medical purposes. Synchrocyclotron SC 1000 medical proton beam with fixed energy of 1000 MeV was put into operation in January 1973 and since 1975 it has been used for medical purposes. A unique "fly-through" method based on irradiation of specific brain sections with protons with fixed energy of 1000 MeV was developed and used for treatment of patients. Low scattering of protons penetrating through an irradiated object combined with the rotation technique of irradiation allows one to provide a very high ratio of the dose in the irradiated zone to the dose at the object's surface. It allows one to irradiate tumors in immediate proximity to the life-critical organs. At the installation for stereotaxic proton therapy, the beam is centered precisely at the target zone. The main element of the installation, the patient's table, provides oscillation in the horizontal plane within the range of ±40°. The anteriour part of the table represents a head-fixation device performing oscillation about the X-axis within ±36°. The crossover of both oscillation axes, vertical and horizontal, as well as the irradiation beam axis perpendicular to them both, is the center of rotation (isocenter). Since 1975 until 2013, 1394 patients were treated with the course of proton therapy at the PNPI synchrocyclotron. 477 cases were the patients with pituitary adenomas, 502 cases – the patients with arteriovenous malformations, 350 patients experienced treatment for the purposes of pain management. In 151 cases the treatment was repeated. 1394 patients are almost 26% of all the patients who experienced proton therapy in Russia and 2% of the patients treated using this therapy in the world. The treatment was performed without damaging the skull and brain tissues. None of the patients had any life-critical complications or complications causing disability. All this proves the efficiency of the method and validity of its application. The results of clinical application of 1000 MeV proton beam in treatment of intracranial abnormal and normal structures allow us to promote further development of this field. Stereotaxic therapy with a narrow high-energy proton beam is a method alternative to surgical treatment. (author)