TY - JOUR AU - Ren, Jianxin AU - Gong, Guanzhong AU - Yao, Xinsen AU - Yin, Yong PY - 2019 TI - Dosimetric comparison of dose accumulation between rigid registration and deformation registration in intensity-modulated radiation therapy for large volume non-small cell lung cancer JF - Translational Cancer Research; Vol 8, No 8 (December 31, 2019): Translational Cancer Research Y2 - 2019 KW - N2 - Background: To evaluate the cumulative dose to the target volumes and organs at risk (OARs) after replanning during intensity-modulated radiation therapy (IMRT) for large volume non-small cell lung cancer (NSCLC) based on rigid registration and deformation registration technologies. Methods: Thirty patients with large volume NSCLC who were treated with IMRT were selected, and two four-dimensional computed tomography (4DCT) scans were acquired before radiotherapy and after 20 fractions of radiotherapy. The initial treatment plan (Plan 1 ) based on the average density projection CT (CT 1-avg ) of the first 4DCT images and the second treatment plan (Plan 2 ) based on CT 2-avg of the second 4DCT images were calculated. Then, the dose distributions of Plan 2 and Plan 1 were accumulated based on rigid and deformation registration technologies to obtain Plan rig and Plan def , respectively. Finally, the volume changes of the gross tumor volume (GTV) and OARs between the two CT scans, and the dose-volume parameters among Plan 1 , Plan 2 , Plan rig and Plan def were compared. Results: Compared with those on the first CT, the mean GTV and heart volume on the second CT decreased by 44.2% and 5.5%, respectively, while the mean volumes of the ipsilateral lung, contralateral lung and total lung increased by 5.2%, 6.2% and 5.8%, respectively. The differences in the above volume parameters between the two CT scans were statistically significant (P 1 , the D 95 , D 98 and V 100% values of the IGTV (GTV fusion of 10 CT phases) and planning target volume (PTV) in Plan 2 did not change significantly (P>0.05), and those of Plan rig and Plan def decreased slightly (P 2 , Plan rig and Plan def were significantly lower than those in Plan 1 (P 30 and the mean dose to the heart in Plan 2 , Plan rig and Plan def decreased by 27.3%, 16.5%, and 15.3% and 15.2%, 6.6%, and 5.6% compared to those in Plan 1 , respectively; V 20 and the mean dose to the total lung in Plan 2 , Plan rig and Plan def decreased by 15.6%, 4.5%, and 3.7% and 15.7%, 6.2%, and 5.1% compared to those in Plan 1 , respectively. Some dose-volume parameters (including D 95 and D 98 to the target volume, V 40 of the heart, V 20 and the mean dose to the ipsilateral lung and the total lung) of Plan def were slightly higher than those in Plan rig (P Conclusions: The dose-volume parameters of OARs in Plan 2 were noticeably different from those in Plan 1 , so all of these parameters have large deviations in evaluating the actual dose to the OARs. And, the dose-volume parameters obtained by deformation registration can better predict the actual dose than those obtained by rigid registration. UR - https://tcr.amegroups.org/article/view/33658