PMID- 34395275 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220425 IS - 2234-943X (Print) IS - 2234-943X (Electronic) IS - 2234-943X (Linking) VI - 11 DP - 2021 TI - Computed Tomography-Based Evaluation of Volume and Position Changes of the Target Region and Organs at Risk During Radiotherapy for Esophageal Cancer: A Pilot Study. PG - 702400 LID - 10.3389/fonc.2021.702400 [doi] LID - 702400 AB - OBJECTIVE: To analyze changes in volume and position of target regions and organs at risk (OARs) during radiotherapy for esophageal cancer patients. METHODS: Overall, 16 esophageal cancer patients who underwent radiotherapy, including 10 cases of intensity-modulated radiation therapy (IMRT) and six of three-dimensional conformal radiotherapy (3D-CRT), were enrolled. The prescription doses for the planning target volumes (PTVs) were as follows: PTV1, 64 Gy/32 fractions; and PTV2, 46 Gy/23 fractions. Repeat computed tomography (CT) was performed for patients after the 5th, 10th, 15th, 20th, and 25th fractions. Delineation of the gross tumor volume (GTV) and OAR volume was determined using five repeat CTs performed by the same physician. The target and OAR volumes and centroid positions were recorded and used to analyze volume change ratio (VCR), center displacement (DeltaD), and changes in the distance from the OAR centroid positions to the planned radiotherapy isocenter (distance to isocenter, DTI) during treatment. RESULTS: No patient showed significant changes in target volume (TV) after the first week of radiotherapy (five fractions). However, TV gradually decreased over the following weeks, with the rate slowing after the fourth week (40 Gy). The comparison of TV from baseline to 40 Gy (20 fractions) showed that average GTVs decreased from 130.7 +/- 63.1 cc to 92.1 +/- 47.2 cc, with a VCR of -29.21 +/- 13.96% (p<0.01), while the clinical target volume (CTV1) decreased from 276.7 +/- 98.2 cc to 246.7 +/- 87.2 cc, with a VCR of -10.34 +/- 7.58% (p<0.01). As TVs decreased, DeltaD increased and DTI decreased. After the fourth week of radiotherapy (40 Gy), centroids of GTV, CTV1, and prophylactic CTV (CTV2) showed average deviations in DeltaD of 7.6 +/- 4.0, 6.9 +/- 3.4, and 6.0 +/- 3.0 mm, respectively. The average DTI of the heart decreased by 4.53 mm (from 15.61 +/- 2.96 cm to 15.16 +/- 2.27 cm). CONCLUSION: During radiotherapy for esophageal cancer, Targets and OARs change significantly in volume and position during the 2(nd)-4(th) weeks. Image-guidance and evaluation of dosimetric changes are recommended for these fractions of treatment to appropriate adjust treatment plans. CI - Copyright (c) 2021 Liu, Peng, Li, Shen, Ma, Chen, Zhang, Fu, Qiu, Liu and Deng. FAU - Liu, Yi-Mei AU - Liu YM AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. AD - Nanfang Hospital, Southern Medical University, Guangzhou, China. FAU - Peng, Ying-Lin AU - Peng YL AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Li, Qi-Wen AU - Li QW AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Shen, Guanzhu AU - Shen G AD - Department of Radiation Oncology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. FAU - Ma, Ya-Ru AU - Ma YR AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Chen, Mei-Ning AU - Chen MN AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Zhang, Jun AU - Zhang J AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Fu, Li-Rong AU - Fu LR AD - Department of Radiation Oncology, The First Affiliated Hospital of Xiamen University, Xiamen, China. FAU - Qiu, Bo AU - Qiu B AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Liu, Hui AU - Liu H AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. FAU - Deng, Xiao-Wu AU - Deng XW AD - Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. LA - eng PT - Journal Article DEP - 20210728 PL - Switzerland TA - Front Oncol JT - Frontiers in oncology JID - 101568867 PMC - PMC8355816 OTO - NOTNLM OT - adaptive radiotherapy OT - esophageal cancer OT - geometric center deviation OT - target retraction OT - volume changed ratio COIS- The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. EDAT- 2021/08/17 06:00 MHDA- 2021/08/17 06:01 PMCR- 2021/01/01 CRDT- 2021/08/16 06:01 PHST- 2021/04/29 00:00 [received] PHST- 2021/07/12 00:00 [accepted] PHST- 2021/08/16 06:01 [entrez] PHST- 2021/08/17 06:00 [pubmed] PHST- 2021/08/17 06:01 [medline] PHST- 2021/01/01 00:00 [pmc-release] AID - 10.3389/fonc.2021.702400 [doi] PST - epublish SO - Front Oncol. 2021 Jul 28;11:702400. doi: 10.3389/fonc.2021.702400. eCollection 2021.