Radiation therapy is the use of ionizing radiation in controlling and treating cancer. Nowadays, various radiation therapy methods are used for more than half of all patients suffering from cancer as partial or whole treatment program. External radiation therapy is one of the radiation therapy methods which is widely applicable and is used for different cancer types. Different radiation types are used in this method, including gamma – and X-radiation (photons), electron beam, protons and heavy ions (e.g. carbon ions). The sources of gamma radiation are radioactive nuclides (usually 60Co) whereas accelerators, which have different types, are used to produce other radiations. Nowadays, a common application of accelerators is their use in treating cancer. Tumor tissues, which are located in different body regions, can be treated easily by means of accelerators. For this aim, electron, photon, proton and carbon ion beams are applied. Linear accelerators are devices that are able to produce electron beams with energies between 5 to 18 MeV. These accelerators, which are very common, are used in electron mode, as well as in X-mode. Using other methods like proton/ion therapy is more efficient for treating tumors that are located adjacent to critical organs. It allows delivering a high dose to the tumor while sparing healthy tissues and organ at risk in tumor’s vicinity, which is the final goal in radiation therapy. Cyclotrons and synchrotrons are the most common accelerators that are applied for this purpose. Normally, cyclotrons are used only for protons and their therapeutic beam radius is within a few centimeters. Although their extracted energy is constant, but using additional equipment makes it possible to achieve different energies from this type of accelerator. Synchrotrons are other circular accelerators which are suitable for proton therapy and other ions therapies as well. They are able to accelerate protons and other ions as well. Their beam radius is within a few centimeter and changing the final beam energy is easily achievable in these types accelerators. To date, 71 centers use proton/ion beams for treating cancer worldwide and 54 centers are under construction or are planned to be constructed.
Iran National Ion Therapy Center will be as the first cancer therapy center, which uses proton and carbon beams for cancer treatment, is equipped by synchrotron accelerator. Construction of Iran National Ion Therapy Center, IRnitc, launched with a groundbreaking ceremony on May 2017. The ceremony was held in the presence of Vice President, Minister of foreign affairs of Iran, Minister of Health and Medical Education, Austrian Ambassador, MedAustron Supervisory Board and MedAustron Managing Director.
The Iran national ion therapy center will be able to deliver 25000 fractions to more than 1200 patients per year. The design and construction phases of this center are in progress with the collaboration MedAustron, the Austrian center for ion therapy, and the nominal capacity will be reached within the next six years. Beside the three treatment rooms, a research room offers opportunities to carry out researches in the fields like medical radiation physics, radiation physics and practical physics.