An implementation of a virtual reality interstitial brachytherapy system

This paper presents an implementation of a virtual reality (VR) interstitial brachytherapy system, and some results related to the accuracies associated with its use. Brachytherapy is a cancer treatment modality whereby applicators are inserted into the patient to act as channels to deliver radioactive sources to the diseased tissue. There are two major shortcomings associated with current brachytherapy procedures: (i) the lack of visual feedback during the insertion of the applicators leads to suboptimal implants, and in turn to inferior treatments, and (ii) the very lengthy planning component of the treatment. We have constructed a VR prototype in which applicators are inserted into a phantom by a user completely immersed in the virtual world, The virtual world consists of: (i) phantom geometry represented in VR image format, which is aligned with the actual phantom, (ii) an electromagnetic tracking device with two receivers, one attached to the applicators and the other to the user's head, and (iii) a variety of tools to aid the user with the insertion of the applicators. Preliminary results suggest that the tracking device is accurate to approximately 1.5 mm for positional measurements, and 1.0 degree for orientational measurements.