Thermal ablation trajectory calculation

A trajectory calculator for calculating a trajectory for an ablation electrode for tissue ablation during an interventional procedure, the trajectory calculator comprising:

• an image interface configured to receive interventional image data;
• a segmentation unit configured to execute a segmentation algorithm on the interventional image data to provide a set of segmentation masks, the set of segmentation masks including at least a tumor mask and a body mask;
• a processing unit configured to
• determine a set of target points based on the tumor mask,
• determine a set of skin entry points based on the body mask, and
• compute a set of trajectory candidates, wherein a trajectory candidate in the set of trajectory candidates includes at least a target point and skin entry point pair;
• a constraint interface configured to receive a set of definable constraints;
• a classifier configured to classify the set of definable constraints in at least two classes, the at least two classes including first type constraints that are mandatory and second type constraints that are not mandatory;
• wherein the processing unit is configured to define differently sized and ordered subsets of trajectory candidates, and wherein the differently sized and ordered subsets differ in conforming with the second type constraints;
• an optimizer configured to
• execute an optimization algorithm on the differently sized and ordered subsets to calculate at least one trajectory, starting with an initial subset, which conforms with all first type constraints and all second type constraints by computing a cost value based on a cost function, and
• in case no solution with 100% tumor coverage is found, iteratively execute the optimization algorithm for a next subset within the differently sized and ordered subsets, so that the second type constraints are stepwise relaxed;
• and
• an output interface configured to provide the at least one trajectory.