TEST OF PRODUCTION OF 198Au RADIOISOTOPE BY MEANS OF TYPICAL MEDICAL LINEAR ACCELERATORS USED IN TELERADIOTHERAPY.

The test of production of the 198Au radioisotope by means of Varian medical linear accelerators used in teleradiotherapy was carried out. The targets made of the natural gold (100% of the 197Au isotope) were irradiated with high-energy therapeutic 20 MV X-ray beam. 198Au was produced in the simple capture reaction 197Au(n;)198Au. The obtained specific activities in the saturation state are relatively low, not exceeding the value of 510.4 kBq/g, because only the high-energy part of the spectrum of 20 MV X-ray beam covers the energy range of the neutron production cross section. Low activity of the 198Au radioisotope produced by medical linear accelerators makes this technique not suitable for a massive production of 198Au for nuclear medicine, but the produced amount of 198Au is sufficient for laboratory tests of new drugs for possible clinical applications. [ABSTRACT FROM AUTHOR]