Treatment planning for a radiosurgical system with general kinematics

In radiosurgery a beam of radiation is used as an ablative surgical instrument to destroy brain tumors. Treatment planning consists of computing a sequence of beam configurations for delivering a necrotic dose to the tumor, without damaging healthy tissue or particularly critical structures. In current systems, kinematic limitations severely constrain beam motion. This often results in inappropriate dose distributions. A new radiosurgical system has been implemented to overcome this disadvantage. In this system, a compact radiation source of high energy is moved by a 6-dof robotic arm. We describe algorithms for computing a motion with specified characteristics for this new system. Treatment plans used at test sites with earlier systems are compared to plans computed with the described algorithms. The experience reported shows that full kinematic flexibility combined with treatment planning algorithms allows for better protection of healthy tissue and higher dosage in tumors