Dosimetry in intrathecal radiogold therapy. 3

By means of the concept of 'specifically absorbed fractions' the absorbed dose depth distribution in the 'continuous slowing down approximation' was calculated for planes and circular cylinder surfaces which were homogeneously charged with 198Au microcolloid. The results enable the determination of the absorbed dose in the spinal and cerebral liquor space after the installation of 198Au microcolloid with known activity distribution. The highest dose values occur in the nerve radices. The thickness of the colloid film on the surfaces of the source organ has no essential influence on the calculated values for the volumes usually instilled for intrathecal therapy. (author)