Developing Needle-Tracking Techniques with Real-Time Transrectal Ultrasound Guidance in GYN Hybrid HDR Brachytherapy

Abstract

Introduction:In interstitial gynecological (GYN) high-dose rate (HDR) brachytherapy, the lack of real-time imaging during procedures is a recognized limitation, often resulting in inaccuracies in needle placement. Traditionally, clinicians rely on a combination of pre-treatment MRI scans and clinical examinations to guide needle placement, but this approach can lead to suboptimal outcomes. To address these challenges and improve the clinical workflow, this research introduces the utilization of a 3D-printed pelvic phantom designed to evaluate the feasibility and efficacy of intraoperative 3D transrectal-ultrasound (TRUS) guidance for needle insertion. Materials and Methods: This research developed needle-tracking techniques utilizing real-time TRUS guidance specifically tailored for GYN malignancies within the context of hybrid HDR brachytherapy. Leveraging the Eigen Health system, originally designed for prostate biopsy, we adapted its real-time imaging capabilities for GYN applications. To facilitate this, anatomical phantoms that replicate female pelvic anatomy were created and optimized. These phantoms served as the cornerstone for a series of feasibility tests that examined the integration of TRUS guidance into brachytherapy workflows. Additionally, comprehensive quality assurance (QA) protocols were established to ensure the reliability of needle tracking and characterization in relation to our ground-truth CT images. The system's MR/TRUS deformable registration algorithm was evaluated through two different experiments. Results: The execution of feasibility tests yielded promising results, demonstrating the Eigen Health system's compatibility with existing brachytherapy workflows and its potential to significantly improve needle placement accuracy. The study also highlighted the system's adaptability to accommodate multiple needle insertions and implement rod-based planning. Through quality assurance evaluations of the reliability and precision of needle characterization, a scaling issue within the needle-tracking system was discovered. Furthermore, the MR-3DUS surface-based elastic registration process was thoroughly examined, with uncertainty variables acknowledged, the preliminary results of this experiment showed that the system can adapt to anatomical variation. Conclusion: The integration of real-time TRUS guidance into GYN HDR brachytherapy significantly improves needle placement accuracy, promising enhanced treatment efficacy and minimized complications. This research contributes valuable insights to medical physics and cancer treatment, paving the way for future clinical trials and potential integration into standard brachytherapy protocols.