Verification of Guiding Needle Placement by Registered Ultrasound Image During Combined Intracavitary/Interstitial Gynecologic Brachytherapy

Abstract

Jing Zeng,1,2 Ziqi Liu,3 Shan Jiang,3 Qingsong Pang,1 Ping Wang1 1Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin, People’s Republic of China; 2Department of Gynecologic Oncology, Tianjin Central Hospital of Gynecology and Obstetrics, Affiliated Hospital of Nankai University, Tianjin, People’s Republic of China; 3School of Mechanical Engineering, Tianjin University, Tianjin, People’s Republic of ChinaCorrespondence: Ping WangTianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin, 300060, People’s Republic of ChinaEmail [email protected]: Our previous research demonstrated that under ideal conditions, rigid registration between MRI images and US images had high accuracy for real-time image guidance. The work presented in this paper focused on the application of the previously established procedures to a new context, including preoperative CT images.Materials and Methods: We used a template to calibrate the US probe and completed the registration between preoperative CT images and US images. Marker experiments on the accuracy of real-time needle trajectories in CT images were performed using micro electromagnetic sensors. Pelvic phantom experiments were carried out to test the registration accuracy between CT and US images, in addition to registration accuracy between US images and real-time needle trajectories (real-time space model).Results: The US probe calibration error in CT images was 0.879 ± 0.149 mm. The difference of registration between US images and CT images was 0.935 ± 0.166 mm in the axial plane (n = 30) and 0.916 ± 0.143 mm in the sagittal plane (n =12). The difference of registration between US images and the needle’s real-time trajectories was 0.951 ± 0.202 mm.Conclusion: Under ideal conditions, rigid registration between CT images and US images had high accuracy for real-time image guidance.Keywords: registered ultrasound image, gynecologic brachytherapy, rigid registration, image-guidance

Keywords

• registered ultrasound image
• gynecologic brachytherapy
• rigid registration
• image-guidance