Abstract: Segmentation of brain tissues is gaining popularity with the advance of image guided surgical approaches. This work proposes a fast and robust practical tool for segmentation of solid tumors in radiosurgery application. For this, a cellular automata (CA) i.e. Tessellation Structure based seeded tumor segmentation method is used on MR images, which standardizes the volume of interest and seed selection. The procedure starts by establishing the connection of CA based segmentation to the graph theoretic methods to show that iterative CA framework solves the shortest path problem by modifying the state transition function from the CA. A sensitive parameter is introduced to adapt the heterogeneous tumor segmentation problem. Then a smo...