Mapping is an important task for mobile robots in general and in Safety, Security, and Rescue Robotics (SSRR) in particular - often maps are even a core mission deliverable for SSRR applications. The assessment of the quality of maps in a simple, efficient and automated way is hence of high interest. But it is not trivial and an ongoing research topic. Here, an overview of advances with a new approach on map evaluation is presented. This structure-based method makes use of a Topology Graph, a topological, abstracted representation of the map. The Topology Graph is constructed by generating and processing a Voronoi Diagram from a 2D grid map. Having a ground truth map, the Topology Graphs of both maps are matched using both similarity metrics on the vertices as well as structural matching of subgraph isomorphisms.