A straightforward implantation method of radioactive sources by means of the Leksell frame

Stereotactic brachytherapy of cerebral gliomas often involves insertion of catheters through the tumor bed. We adopted the hexagonal tube configuration around a central tube. Such a configuration is applicable to most commonly occurring brain tumors. In order to perform a low-cost, accurate and straightforward implantation, a robust mathematical derivation of all relevant formulas is used to transform CT coordinates to Leksell frame coordinates, including derivations for the two stereotactic angles. The coordinates of the seven tubes (which are essential if no template is available) and the length of the radioactive source are also derived, and an example is presented. The calculations have been implemented on a personal computer (Intel processor 386 or higher). Additional options, such as choosing other stereotactic angles than the calculated ones and rotating the tube configuration around the central tube, are integrated into the program.