TY - JOUR

T1 - Accuracy and consistency of intensity-based deformable image registration in 4DCT for tumor motion estimation in liver radiotherapy planning

AU - Tascon-Vidarte, Jose D.

AU - Stick, Line Bjerregaard

AU - Josipovic, Mirjana

AU - Risum, Signe

AU - Jomier, Julien

AU - Erleben, Kenny

AU - Vogelius, Ivan Richter

AU - Darkner, Sune

N1 - Publisher Copyright: © 2022 Tascón-Vidarte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

PY - 2022/7

Y1 - 2022/7

N2 - We investigate the accuracy of intensity-based deformable image registration (DIR) for tumor localization in liver stereotactic body radiotherapy (SBRT). We included 4DCT scans to capture the breathing motion of eight patients receiving SBRT for liver metastases within a retrospective clinical study. Each patient had three fiducial markers implanted. The liver and the tumor were delineated in the mid-ventilation phase, and their positions in the other phases were estimated with deformable image registration. We tested referenced and sequential registrations strategies. The fiducial markers were the gold standard to evaluate registration accuracy. The registration errors related to measured versus estimated fiducial markers showed a mean value less than 1.6mm. The positions of some fiducial markers appeared not stable on the 4DCT throughout the respiratory phases. Markers' center of mass tends to be a more reliable measurement. Distance errors of tumor location based on registration versus markers center of mass were less than 2mm. There were no statistically significant differences between the reference and the sequential registration, i.e., consistency and errors were comparable to resolution errors. We demonstrated that intensitybased DIR is accurate up to resolution level for locating the tumor in the liver during breathing motion.

AB - We investigate the accuracy of intensity-based deformable image registration (DIR) for tumor localization in liver stereotactic body radiotherapy (SBRT). We included 4DCT scans to capture the breathing motion of eight patients receiving SBRT for liver metastases within a retrospective clinical study. Each patient had three fiducial markers implanted. The liver and the tumor were delineated in the mid-ventilation phase, and their positions in the other phases were estimated with deformable image registration. We tested referenced and sequential registrations strategies. The fiducial markers were the gold standard to evaluate registration accuracy. The registration errors related to measured versus estimated fiducial markers showed a mean value less than 1.6mm. The positions of some fiducial markers appeared not stable on the 4DCT throughout the respiratory phases. Markers' center of mass tends to be a more reliable measurement. Distance errors of tumor location based on registration versus markers center of mass were less than 2mm. There were no statistically significant differences between the reference and the sequential registration, i.e., consistency and errors were comparable to resolution errors. We demonstrated that intensitybased DIR is accurate up to resolution level for locating the tumor in the liver during breathing motion.

UR - http://www.scopus.com/inward/record.url?scp=85133713246&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0271064

DO - 10.1371/journal.pone.0271064

M3 - Journal article

C2 - 35802593

AN - SCOPUS:85133713246

VL - 17

SP - 1

EP - 15

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 7 July

M1 - e0271064

ER -