Fast 3D medial axis transformation to reduce computation and complexity in radiosurgery treatment planning

The medial axis analysis of an object can be used to effectively guide and optimize radiosurgery treatment planning. In this paper, a fast Euclidean medial axis transformation in three dimensions based on dynamic grassfire simulation and ridge extraction is presented. A ridge occurs when fire fronts collapse during grassfire propagation. Iso-contours(2D) or iso-surfaces(3D) can be obtained from dynamic grassfire transforms. They are locally smooth everywhere except at ridge locations. Ridges are detected by measuring local curvature at each point. This process is invariant under spatial translations and rotations. The algorithm yields the true Euclidean skeleton of the objects and is several orders of magnitude faster than other thinning methods. In radiosurgery treatment planning, optimal shots are only placed on the medial axis of the 3D target, which reduces optimization time and complexity. An example of a treatment planning process will be presented and the relationship between skeleton disks and the dose distributions which they predict will be discussed.

Duke Scholars

Author Qingrong Jackie Wu Radiation Oncology