PT  - JOURNAL ARTICLE
AU  - UEDA, YOSHIHIRO
AU  - TSUJII, MARI
AU  - OHIRA, SHINGO
AU  - SUMIDA, IORI
AU  - MIYAZAKI, MASAYOSHI
AU  - TESHIMA, TERUKI
TI  - Residual Set Up Errors of the Surrogate-guided Registration Using Four-dimensional CT Images and Breath Holding Ones in Respiratory Gated Radiotherapy for Liver Cancer
AID  - 10.21873/invivo.12478
DP  - 2021 Jul 01
TA  - In Vivo
PG  - 2089--2098
VI  - 35
IP  - 4
4099  - http://iv.iiarjournals.org/content/35/4/2089.short
4100  - http://iv.iiarjournals.org/content/35/4/2089.full
SO  - In Vivo2021 Jul 01; 35
AB  - Background/Aim: To evaluate the surrogate-guided registration accuracy of two computed tomography (CT) image sets, expiratory phase four-dimensional (Ex4D) CT and breath-holding CT (BHCT), in respiratory-gated radiotherapy for liver cancer. Materials and Methods: The surrogate-guided registration errors were defined as the differences between the diaphragm- and fiducial-guided registrations or the differences between upper and lower fiducial registrations in three directions: left–right (LR), anterior–posterior (AP), and cranio–caudal (CC). Results: The mean±SDs of the absolute errors for diaphragm-guided registration were 1.9±1.3, 2.7±1.8, and 2.6±1.7 mm with Ex4D and 1.8±1.8, 2.6±1.9, and 1.8±1.7 mm with BHCT in the LR, AP and CC directions, respectively (CC direction, p<0.01). In the fiducial-guided registration, there were no significant differences in any direction. In registration with Ex4D, there were positive correlations between registration errors and the respiratory irregularity during 4D scanning (correlation coefficient; diaphragm: 0.65, fiducial: 0.54). Conclusion: BHCT has the advantage of accurate surrogate-guided registration compared with Ex4D.