A.Vasidov, E.A.Markelova and S.Khujaev
Nuclear Chemistry Laboratory, Institute of Nuclear Physics, Tashkent, Uzbekistan
The important problem of modern oncology is the direct action of low energy γ-quanta in range 20-40 KeV on tumor tissue with minimal damage of healthy cells. Such irradiators are 125I, 103Pd and 131Cs radionuclides in titanium microcapsules, and they are injected in tumor under observation of ultrasonic device or single-photon scintillation tomograph in amount 60-100 pieces. The fabrication of X-ray sources in titanium or glass capsules in our conditions is related with some technical difficulties and availability of high-tech equipment. That's why the aim of this work was the elaboration of production technology of 131Cs and spherical hermetic biocompatible and biodegrading biopolymer X-ray sources by simplified and cheap methods.
As result of many years investigations the following method were elaborated – the dissolution of high active barium oxide with the use of microwave radiation and extraction of 131Cs with high radionuclide purity;- the full sorption of 131Cs ions in chitosan ferment modified with additions of potassium ferricyanide and transition element chlorides; - forming of spherical biopolymer sources by doser transmitting viscous drops through air layer and two-layer sedimentation bath from alkali solution and xylene. The impermeability of granules obtained was made by their treatment with glutaraldehydes.
Keywords: 131Cs, brachytherapy, chitosan.