A system for navigation support, comprising: - an image data input; - a data processor; - a marker detecting arrangement; and - an output interface; wherein the marker detecting arrangement is configured to detect a current spatial location of a set of markers assigned to the subject; wherein the image data input is configured to receive a plurality of acquired 2D X-ray images of a subject's body from different angles; wherein the set of markers are visible in the X-ray images; wherein the data processor is configured to: - reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is positioned outside the volume covered by the reconstructed 3D volume of the subject2D X-ray images; and - identify at least said part of the markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determine a spatial location of the markers in relation to the 3D volume of the subject; and - register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the current spatial location of the markers as detected by the marker detecting arrangement and the determined spatial location of the markers in relation to the 3D volume of the subject; wherein the output interface is configured to provide the registered reconstructed 3D volume for navigation support. - an image data input; - a data processor; - a marker detecting arrangement; and - an output interface; wherein the marker detecting arrangement is configured to detect a current spatial location of a set of markers assigned to the subject; wherein the image data input is configured to receive a plurality of acquired 2D X-ray images of a subject's body from different angles; wherein the set of markers are visible in the X-ray images; wherein the data processor is configured to: - reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is positioned outside the volume covered by the reconstructed 3D volume of the subject2D X-ray images; and - identify at least said part of the markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determine a spatial location of the markers in relation to the 3D volume of the subject; and - register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the current spatial location of the markers as detected by the marker detecting arrangement and the determined spatial location of the markers in relation to the 3D volume of the subject; wherein the output interface is configured to provide the registered reconstructed 3D volume for navigation support. wherein the marker detecting arrangement is configured to detect a current spatial location of a set of markers assigned to the subject; wherein the image data input is configured to receive a plurality of acquired 2D X-ray images of a subject's body from different angles; wherein the set of markers are visible in the X-ray images; wherein the data processor is configured to: - reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is positioned outside the volume covered by the reconstructed 3D volume of the subject2D X-ray images; and - identify at least said part of the markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determine a spatial location of the markers in relation to the 3D volume of the subject; and - register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the current spatial location of the markers as detected by the marker detecting arrangement and the determined spatial location of the markers in relation to the 3D volume of the subject; - reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is positioned outside the volume covered by the reconstructed 3D volume of the subject2D X-ray images; and - identify at least said part of the markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determine a spatial location of the markers in relation to the 3D volume of the subject; and - register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the current spatial location of the markers as detected by the marker detecting arrangement and the determined spatial location of the markers in relation to the 3D volume of the subject; wherein the output interface is configured to provide the registered reconstructed 3D volume for navigation support.