Robotic Path-finding in Inverse Treatment Planning with Continuous Dose Delivery for Stereotactic Radiosurgery

Abstract

Continuous dose delivery, or continuous path (CP) treatment, in stereotactic radiosurgery has been proven to improve the total treatment time, dose conformity, and dose distribution homogeneity over traditional step-and-shoot delivery. We develop several automated planning methods using robotic path-finding techniques to design CP treatments for SRS with Gamma Knife Perfexion. Using simultaneous localization and mapping (SLAM), we construct paths through the target that pass sufficiently close to a set of pre-selected isocentre locations. To solve SLAM, both the traditional extended Kalman filter (EKF) and incremental smoothing and mapping (iSAM) algorithms are investigated. Steering decision algorithms using heuristic scoring methods and robotic exploration techniques, specifically, frontiers, are investigated. Once a path is found, shot delivery from each sector is optimized along the path using inverse planning optimization. The SLAM methods consistently improve dose metrics and beam-on time compared to the clinical and an earlier graph-based Hamiltonian path CP planning approach.M.A.S