A New CT Prostate Segmentation for CT-Based HDR Brachytherapy

• Type of Material: Conference Paper
• Authors: Xiaofeng Yang, Emory University; Peter Rossi, Emory University; Tomi Ogunleye, Emory University; Ashesh Jani, Emory University; Walter Curran, Emory University; Tian Liu, Emory University
• Language: English
• Date: 2014-01-01
• Publisher: Emory University Libraries
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 SPIE.
• Final Published Version (URL): http://dx.doi.org/10.1117/12.2043695
• Title of Journal or Parent Work: MEDICAL IMAGING 2014: IMAGE-GUIDED PROCEDURES, ROBOTIC INTERVENTIONS, AND MODELING
• Conference or Event Name: Conference on Medical Imaging - Image-Guided Procedures, Robotic Interventions, and Modeling
• Volume: 9036
• Start Page: 90362K
• End Page: 90362K
• Grant/Funding Information: This research is supported in part by the Department of Defense (DoD) Prostate Cancer Research Program (PCRP) Award W81XWH-13-1-0269 and National Cancer Institute (NCI) Grant CA114313.
• Keywords: MRI; Prostate; ultrasound-guided; Engineering; REGISTRATION; CT; Optics; transrectal ultrasound (TRUS); Robotics; Physical Sciences; Technology; Science & Technology; HDR; RADIOTHERAPY; segmentation; Engineering, Biomedical; Life Sciences & Biomedicine; brachytherapy; Radiology, Nuclear Medicine & Medical Imaging; TRANSRECTAL ULTRASOUND; CANCER; VOLUME
• Research Categories: Engineering, Biomedical; Health Sciences, Oncology; Health Sciences, Radiology

Abstract

High-dose-rate (HDR) brachytherapy has become a popular treatment modality for localized prostate cancer. Prostate HDR treatment involves placing 10 to 20 catheters (needles) into the prostate gland, and then delivering radiation dose to the cancerous regions through these catheters. These catheters are often inserted with transrectal ultrasound (TRUS) guidance and the HDR treatment plan is based on the CT images. The main challenge for CT-based HDR planning is to accurately segment prostate volume in CT images due to the poor soft tissue contrast and additional artifacts introduced by the catheters. To overcome these limitations, we propose a novel approach to segment the prostate in CT images through TRUS-CT deformable registration based on the catheter locations. In this approach, the HDR catheters are reconstructed from the intra-operative TRUS and planning CT images, and then used as landmarks for the TRUS-CT image registration. The prostate contour generated from the TRUS images captured during the ultrasound-guided HDR procedure was used to segment the prostate on the CT images through deformable registration. We conducted two studies. A prostate-phantom study demonstrated a submillimeter accuracy of our method. A pilot study of 5 prostate-cancer patients was conducted to further test its clinical feasibility. All patients had 3 gold markers implanted in the prostate that were used to evaluate the registration accuracy, as well as previous diagnostic MR images that were used as the gold standard to assess the prostate segmentation. For the 5 patients, the mean gold-marker displacement was 1.2 mm; the prostate volume difference between our approach and the MRI was 7.2%, and the Dice volume overlap was over 91%. Our proposed method could improve prostate delineation, enable accurate dose planning and delivery, and potentially enhance prostate HDR treatment outcome.