A system for dynamic localization of medical instruments includes an ultrasound imaging system (110) configured to image a volume where one or more medical instruments are deployed. A registration module (136) registers two images of the one or more medical instruments to compute a transform between the two images, the two images being separated in time. A planning module (142) is configured to have positions of the volume and the one or more medical instruments updated based on the transform and, in turn, update a treatment plan in accordance with the updated positions such that changes in the volume and positions of the one or more medical instruments are accounted for in the updated plan.
