Reality-Based Estimation of Needle and Soft-Tissue Interaction for Accurate Haptic Feedback in Prostate Brachytherapy Simulation

Abstract

Prostate Brachytherapy is the implantation of radioactive seeds into the prostate as a treatment for prostate cancer. The success rate of the procedure is directly related to the physician’s level of experience. In addition, minor deviations in seed alignment caused by gland compression/retraction, gland edema (swelling) and needle deflections can create significant areas of over or under dosage to the gland and/or injury to surrounding nerves and organs, leading to increased morbidity. Therefore, reductions in brachytherapy complication rates will be dependent on improving the tools physicians use for training to improve the accuracy of needle guidance and deployment of ‘seeds’ within the prostate gland. Through our novel approach of using two C-ARM fluoroscopes, we propose a reality-based approach for estimating needle and soft tissue interaction for the purpose of eventually developing an accurate seed placement training simulator with haptic feedback for prostate brachytherapy. By recording implanted fiducial movement and needle-soft tissue interaction forces, we can: extract the local effective modulus during puncture events, quantify tissue deformation, obtain an approximate cutting force, and build a finite element model to provide accurate haptic feedback in the training simulator for needle insertion tasks.

This work was supported in part by National Science Foundation CAREER award IIS 0133471, NSF ITR award 0312709, and Beukenkamp Foundation.