Abstract: Systems, methods and apparatus are provided through which a tumor resection planning tool in mixed reality comprises apparatuses for image registration, synchronous navigation through fused datasets, segmentation and labeling of surgery-related structures, manual correction of segmentation results, and a browser-based tool for clinical validation. In some implementations the tumor resection planning tool generates a step-by-step surgical tumor resection plan adaptable to organs such as liver, pancreas, lung, and brain. In some implementation the tumor resection planning tool displays segmented structures as 3D polygonal objects with customizable textures, transparency, and color. Risk margins offset from tumor surfaces are visualized with user-defined values. In some implementations vessel clip plan tool(s) simulate post-resection blood flow. Users can create, modify, and share resection plans, dividing organ structures based on user-defined plans.