title: Improved prostate delineation in prostate HDR brachytherapy with TRUS-CT deformable registration technology: A pilot study with MRI validation.
abstract: Accurate prostate delineation is essential to ensure proper target coverage and normal-tissue sparing in prostate HDR brachytherapy. We have developed a prostate HDR brachytherapy technology that integrates intraoperative TRUS-based prostate contour into HDR treatment planning through TRUS-CT deformable registration (TCDR) to improve prostate contour accuracy. In a perspective study of 16 patients, we investigated the clinical feasibility as well as the performance of this TCDR-based HDR approach. We compared the performance of the TCDR-based approach with the conventional CT-based HDR in terms of prostate contour accuracy using MRI as the gold standard. For all patients, the average Dice prostate volume overlap was 91.1 ± 2.3% between the TCDR-based and the MRI-defined prostate volumes. In a subset of eight patients, inter and intro-observer reliability study was conducted among three experienced physicians (two radiation oncologists and one radiologist) for the TCDR-based HDR approach. Overall, a 10 to 40% improvement in prostate volume accuracy can be achieved with the TCDR-based approach as compared with the conventional CT-based prostate volumes. The TCDR-based prostate volumes match closely to the MRI-defined prostate volumes for all 3 observers (mean volume difference: 0.5 ± 7.2%, 1.8 ± 7.2%, and 3.5 ± 5.1%); while CT-based contours overestimated prostate volumes by 10.9 ± 28.7%, 13.7 ± 20.1%, and 44.7 ± 32.1%. This study has shown that the TCDR-based HDR brachytherapy is clinically feasible and can significantly improve prostate contour accuracy over the conventional CT-based prostate contour. We also demonstrated the reliability of the TCDR-based prostate delineation. This TCDR-based HDR approach has the potential to enable accurate dose planning and delivery, and potentially enhance prostate HDR treatment outcome.
authors.affiliation: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rossi
authors.affiliation: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Ashesh B
authors.initials: AB
authors.lastname: Jani
authors.affiliation: Department of Radiology and Imaging Sciences and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, Nanjing, China.
authors.forename: Zhengyang
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Curran
authors.affiliation: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors.forename: Tian
authors.initials: T
authors.lastname: Liu
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010865:Pilot Projects; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000528:radiation effects; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*
keywords: 
  CT
  ; HDR brachytherapy; TRUS‐CT registration; prostate contour; transrectal ultrasound (TRUS)