Exhibit Hall | Forum 7
Purpose: Accurate identification of treatment catheters’ track and its relative position to patient anatomy is necessary for proper delivery of high-dose-rate (HDR) brachytherapy treatment. Most clinics have utilized transrectal ultrasound (TRUS) imaging as the primary target delineation and catheter identification technique. Using ultrasound images to identify catheters can be subjective, time-consuming, and prone to errors. This report aims to provide a clinical workflow for implementing electromagnetic tracking (EMT) in a clinical setting while providing cross-comparison of the accuracy of catheter identification using EMT, ultrasound, and computed tomography (CT) information.
Methods: A 3D Guidance trackSTAR, Mid-Range transmitter, and 6DOF sensors (NDI, Ontario, Canada) were used. This experiment was performed in an actual operating room to simulate and study the effects of electromagnetic noise from surrounding equipment. Five catheters were implanted in a prostate phantom (SIM) from JJ-MEDTECH. Three electromagnetic sensors were used; one for tracking and two for establishing the relationship between the EMT system and imaging coordinates (ultrasound and CT). Each catheter was reconstructed utilizing the tracking sensor's continuous data collection technique. We acquired a 3D ultrasound image set and CT concurrently for comparison. A routine permitting the import of EMT data into Eclipse (Varian, Palo Alto, California) for planning and representation was written. Reconstruction time and accuracy (US-based vs. EMT) are reported.
Results: Reconstruction time was 60±15s for US (mean ± 1 SD) and 9±3s for EMT per catheter. EMT reconstruction accuracy vs. CT was 0.4±0.2mm, 0.5±0.2mm, 0.3±0.2mm, 0.7±0.3mm in Ant-Pos, Lat-Mid, Sup-Inf, and 3D, respectively. While comparing EMT catheter reconstruction accuracy using ultrasound indicates mean residual error 0.5±0.3mm, 0.5±0.3mm, 0.6±0.2mm in Ant-Pos, Lat-Mid, Sup-Inf, respectively, with a mean 3D-value of 0.9mm±0.4mm.
Conclusion: Our preclinical study demonstrated EMT could accurately reconstruct the catheter track implanted in the prostate phantom and reduce planning time for US-based HDR prostate brachytherapy.
Brachytherapy, HDR, Prostate Therapy