Development of technology for supplementary therapy of oncological diseases. Use of high Z elements in radiotherapy

Ph.D. in Med., Assistant professor,
Leading Researcher, Laboratory of methods and technologies of radiation therapy, Department of Medical Radiation Technologies.

The key to improving the effectiveness of radiation therapy is the “contrast”, which is to maximize the dose of ionizing radiation delivered to the tumor while minimizing the dose received by healthy tissues. Radiation therapy uses mainly “geometric” radiation targeting to a tumor. Increasing the targeting accuracy allows increasing both the radiation dose absorbed by the tumor and the effective dose, at the same time reducing the physical dose of radiation to closely located critical organs. However, it is difficult to determine “geometrically” accurately the boundaries of the tumor and critical organs. In addition, “geometric” targeting is possible only for photon radiation, which limits the applicability for tumors with low radiosensitivity.
It is proposed to use “physico-biological” targeting to ensure high contrast during irradiation. In this case, the process is divided into two stages: 1) a drug is injected into the body/tumor, containing a chemical element with a large Z, which accumulates in the tumor, 2) irradiation of the tumor. Due to the high cross section of the interaction (neutrons or photons) with the drug, the energy release in tumor tissues is significantly higher than in healthy tissues. With this technology "targeting" is performed by an increased concentration of the drug in the tumor.
The implementation of the approach requires not only an understanding of how and when a “supplementary element” enters the tumor cell and/or its organelles, but also an experimental verification of the pharmacokinetic model of accumulation of elements with large Z in various cells and tissues of humans and animals.