PV QA 3 - Poster Viewing Q&A 3
TU_28_3087 - A Multicentral Quality Assurance Study of Target Volume Delineation for A Prospective, Random, Multicenter Study: 3JECOG P-01
Tuesday, October 23
1:00 PM - 2:30 PM
Location: Innovation Hub, Exhibit Hall 3
A Multicentral Quality Assurance Study of Target Volume Delineation for A Prospective, Random, Multicenter Study: 3JECOG P-01
X. Chang1, Z. Xiao1, X. Wang2, Y. Tian3, W. Zhang4, J. Q. Chen5, K. X. Zhang6, G. Li7, X. Qiao8, C. Han9, Y. T. Wang10, M. L. Liu11, X. C. Sun12, X. S. Gao13, Y. Shi14, F. Zhang15, Z. L. Yu16, J. Yang17, Y. D. Zhao18, and H. Ge19; 1Department of Radiation Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 3National Cancer Center/ Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 4Tianjin Medical University Cancer Hospital & Institute, Tianjin, China, 5Fujian Cancer Hospital, Fuzhou, Fujian Province, China, 6TengZhou Central People’s hospital, Tengzhou, Shandong Province, China, 7Beijing Hospital, Beijing, China, 8Fourth Hospital of Hebei Medical University, Shijiazhuang, China, 9Department of Radiation Oncology , the Fourth Hospital of Hebei Medical University, Shijiazhuang, China, 10PLA Army General Hospital, Beijing, China, 11Affiliated Hospital of Hebei University, Baoding, China, 12Jiangsu Province Hospital, Jiangsu Province, China, 13Department of Radiation Oncology, Peking University First Hospital, Beijing, China, 14Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, 15Department of radiation oncology, Peking Union Medical College Hospital. Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China, 16The Affiliated Hospital of Inner MONGOLIA Medical University, Inner MONGOLIA, China, 17Department of Oncology, The first Affiliated Hospital of Xinxiang Medical University, Weihui, China, 18Anyang Tumor Hospital, Henan Province, China, 19The Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, China
Purpose/Objective(s): 3JECOG P-01 is a prospective, random, multicenter study of simultaneous integrated boost intensity modulated radiation therapy (SIB-IMRT) with S1 in elderly patients with esophageal cancer (EC). The purpose of our study is to discover the difference in target delineation among different hospitals, and explore a possible method to achieve higher quality assurance.
Materials/Methods: Three representative EC patients，including upper, middle, and lower thoracic portions, were selected and sent to each hospital to be contoured based on their own contouring principles for the first time. Subsequently, a contouring protocol, revised at the second Multicenter Conference, was sent to each center for the second time of contouring.After completion, an experienced physicist was invited to accomplish all radiotherapy plans. The degree of target dispersion was quantified using standard deviation (St.D) for both target volumes and dosimetric parameters, as well as spatial conformability (SC) for the spatial overlap of multicenter target volumes.
Results: We defined the first contouring volumes as the routine group and the second as the protocol group. A total of 16 radiation oncologists were involved in this study, of which 9 provided both groups of target volumes. For distal case, degree of target dispersion in clinical target volume (CTV) and mean lung dose (MLD) was large between the two groups, with St.D of 80.54, and 114.07 in the routine group , comparing individually with 65.84 and 65.39 in the protocol group. Besides, SC in PTV and gross tumor volumes（GTV）showed an significant enhancement, from 0.42 and 0.40 to 0.56 (P=0.009) and 0.74 (P=0.005).Similar results were observed in upper and middle cases, in that SC in GTV enhanced significantly, and St.d in dosimtric parameters was reduced to a certain extent. This is in contrast to SC in CTV, which did not achieve significant increase.
Conclusion: Significant intercentral variation was observed in SIB-IMRT fields for elder EC patients, especially for those cases with distant lymph node metastasis. A clear contouring protocol, evidently necessary for mandatory quality assurance, can ensure that the degree of dispersion in target volumes, as well as its relative dosimetric parameters, are controlled. Ultimately this will ensure a solid foundation for the reliability of the research results.
Author Disclosure: X. Chang: None. Z. Xiao: None. G. Li: None. C. Han: None.