AUTHOR=Li Fengxiang , Li Yankang , Wang Xue , Zhang Yingjie , Liu Xijun , Liu Shanshan , Wang Wei , Wang Jinzhi , Guo Yanluan , Xu Min , Li Jianbin 

TITLE=Inter-Observer and Intra-Observer Variability in Gross Tumor Volume Delineation of Primary Esophageal Carcinomas Based on Different Combinations of Diagnostic Multimodal Images

JOURNAL=Frontiers in Oncology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.817413

DOI=10.3389/fonc.2022.817413

ISSN=2234-943X

ABSTRACT=<sec><title>Background and Purpose</title><p>This study aimed to investigate inter-/intra-observer delineation variability in GTVs of primary esophageal carcinomas (ECs) based on planning CT with reference to different combinations of diagnostic multimodal images from endoscopy/EUS, esophagography and FDG-PET/CT.</p></sec><sec><title>Materials and Methods</title><p>Fifty patients with pathologically proven thoracic EC who underwent diagnostic multimodal images before concurrent chemoradiotherapy were enrolled. Five radiation oncologist independently delineated the GTVs based on planning CT only (GTV<sub>C</sub>), CT combined with endoscopy/EUS (GTV<sub>CE</sub>), CT combined with endoscopy/EUS and esophagography (X-ray) (GTV<sub>CEX</sub>), and CT combined with endoscopy/EUS, esophagography, and FDG-PET/CT (GTV<sub>CEXP</sub>). The intra-/inter-observer variability in the volume, longitudinal length, generalized CI (CI<sub>gen</sub>), and position of the GTVs were assessed.</p></sec><sec><title>Results</title><p>The intra-/inter-observer variability in the volume and longitudinal length of the GTVs showed no significant differences (<italic>p&gt;</italic>0.05). The mean intra-observer CI<sub>gen</sub> values for all observers was 0.73 ± 0.15. The mean inter-observer CI<sub>gen</sub> values for the four multimodal image combinations was 0.67 ± 0.11. The inter-observer CI<sub>gen</sub> for the four combined images was the largest, showing significant differences with those for the other three combinations. The intra-observer CI<sub>gen</sub> among different observers and inter-observer CI<sub>gen</sub> among different combinations of multimodal images showed significant differences (<italic>p</italic>&lt;0.001). The intra-observer CI<sub>gen</sub> for the senior radiotherapists was larger than that for the junior radiotherapists (<italic>p</italic>&lt;0.001).</p></sec><sec><title>Conclusion</title><p>For radiation oncologists with advanced medical imaging training and clinical experience, using diagnostic multimodal images from endoscopy/EUS, esophagography, and FDG-PET/CT could reduce the intra-/inter-observer variability and increase the accuracy of target delineation in primary esophageal carcinomas.</p></sec>