Abstract: A pre-computed importance function providing ex ante assessment of optimal placement of a single radioactive source is used for sequential placement of multiple radioactive sources. As each source is placed, the importance function may be modified to reflect the dose implemented by that source and all sources already placed. The greedy algorithm employed by this technique makes possible optimization of additional dimensions of treatment planning including, using directional and isotropic sources, using different source isotopes, using optimum source strengths, using source locations that are not on the regular grid and using a single movable source for variable times at different locations.

Abstract: Radioactive sources for implanting in tissue to treat tumors and to provide a directional dose to allow improved dose placement, particularly at the interface between healthy and diseased tissue.

Abstract: A pre-computed importance function providing ex ante assessment of optimal placement of a single radioactive source is used for sequential placement of multiple radioactive sources. As each source is placed, the importance function may be modified to reflect the dose implemented by that source and all sources already placed. The greedy algorithm employed by this technique makes possible optimization of additional dimensions of treatment planning including, using directional and isotropic sources, using different source isotopes, using optimum source strengths, using source locations that are not on the regular grid and using a single movable source for variable times at different locations.

Abstract: A pre-computed sensitivity function providing ex ante assessment of optimal placement of a single radioactive seed, is used for sequential placement of multiple radioactive seeds. The location of each successive seed may also be constrained by an exclusion function omitting areas in the target receiving a pre-defined dose from the preexisting seeds. This technique makes possible optimization of additional dimensions of treatment planning including using a different number of needles and using mixed seed types.

Abstract: A pre-computed sensitivity function providing ex ante assessment of optimal placement of a single radioactive seed, is used for sequential placement of multiple radioactive seeds. The location of each successive seed may also be constrained by an exclusion function omitting areas in the target receiving a pre-defined dose from the preexisting seeds. This technique makes possible optimization of additional dimensions of treatment planning including using a different number of needles and using mixed seed types.

Abstract: An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable section or the base facing the absorber across a small gap. The radioactive source emits charged particles such as electrons, resulting in a buildup of charge on the absorber, drawing the absorber and source together and storing mechanical energy as the deformable element is bent. When the force between the absorber and the source is sufficient to bring the absorber into effective electrical contact with the source, discharge of the charge between the source and absorber allows the deformable element to spring back, releasing the mechanical energy stored in the element.

Abstract: An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable section or the base facing the absorber across a small gap. The radioactive source emits charged particles such as electrons, resulting in a buildup of charge on the absorber, drawing the absorber and source together and storing mechanical energy as the deformable element is bent. When the force between the absorber and the source is sufficient to bring the absorber into effective electrical contact with the source, discharge of the charge between the source and absorber allows the deformable element to spring back, releasing the mechanical energy stored in the element.