SU-E-T-154: Establishment and Implement of 3D Image Guided Brachytherapy Planning System

Abstract

Purpose: Cannot observe the dose intuitionally is a limitation of the existing 2D pre‐implantation dose planning. Meanwhile, a navigation module is essential to improve the accuracy and efficiency of the implantation. Hence a 3D Image Guided Brachytherapy Planning System conducting dose planning and intra‐operative navigation based on 3D multi‐organs reconstruction is developed. Methods: Multi‐organs including the tumor are reconstructed in one sweep of all the segmented images using the multiorgans reconstruction method. The reconstructed organs group establishs a three‐dimensional visualized operative environment. The 3D dose maps of the three‐dimentional conformal localized dose planning are calculated with Monte Carlo method while the corresponding isodose lines and isodose surfaces are displayed in a stereo view. The real‐time intra‐operative navigation is based on an electromagnetic tracking system (ETS) and the fusion between MRI and ultrasound images. Applying Least Square Method, the coordinate registration between 3D models and patient is realized by the ETS which is calibrated by a laser tracker. The system is validated by working on eight patients with prostate cancer. The navigation has passed the precision measurement in the laboratory. Results: The traditional marching cubes (MC) method reconstructs one organ at one time and assembles them together. Compared to MC, presented multi‐organs reconstruction method has superiorities in reserving the integrality and connectivity of reconstructed organs. The 3D conformal localized dose planning, realizing the “exfoliation display” of different isodose surfaces, helps make sure the dose distribution has encompassed the nidus and avoid the injury of healthy tissues. During the navigation, surgeons could observe the coordinate of instruments real‐timely employing the ETS. After the calibration, accuracy error of the needle position is less than 2.5mm according to the experiments. Conclusion: The speed and quality of 3D reconstruction, the efficiency in dose planning and accuracy in navigation all can be improved simultaneously.

Design, analysis and control of a novel tendon-driven magnetic resonance–guided robotic system for minimally invasive breast surgery

“…As shown in Figure 6, the workflow description is as follows— Step 1 : the structure of breast tissue and tumor position are acquired from the nuclear magnetic resonance (NMR) device before the acupuncture operation, and then the MR image data containing these information will be sent to IGBT software, 17 in which image segmentation and 3D reconstruction will be completed to make a virtual organ model. Step 2 : insertion trajectory planning based on the virtual model will be done to obtain a secure insertion route to avoid puncturing other tissues.…”