2211 - Efficacy and Safety of Different Dose Patterns in Concurrent Integrated Radiotherapy for Esophageal Cancer: A Multicenter Real-World Study
Presenter(s)
J. Dong1, S. Wen2, Y. Zhang3, J. Chen4, X. Wang5, C. Wang6, Y. Liu7, P. Qian7, J. Z. Cao8, Q. Hou8, Y. Xu9, Z. Lin9, X. Ye10, M. Hou11, Y. Gui11, L. Wang12, W. Zhou13, Z. Zeng14, Y. Song15, H. Luo15, J. Lv16, J. Wen2, X. Liu2, and W. Shen2; 1Tangshan Gongren Hospital, Tangshan, Hebei, China, 2The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China, 3Anyang Cancer Hospital, Anyang, Henan, China, 4Peace hospital of Changzhi Medical College, Changzhi, Hebei, China, 5Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, China, 6Anyang Tumor Hospital, Anyang, Henan, China, 7Nanjing Medical University Affiliated Cancer Hospital, Nanjing, Jiangsu, China, 8Cancer Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China, 9Fujian Cancer Hospital, Fuzhou, Fujian, China, 10Department of Radiation Oncology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China, 11Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, China, 12Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China, 13Chongqing University Cancer Hospital, Chongqing, Chongqing, China, 14the second affliated hospital of Nanchang University, Nanchang, China, 15Huai’an First People’s Hospital, Huai'an, Jiangsu, China, 16Sichuan Clinical Research Center for Cancer,Sichuan Hospital Cancer & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu, China
Purpose/Objective(s): This multicenter study aimed to compare the efficacy and safety of the simultaneous integrated boost (SIB) regimen with two involved-field irradiation (IFI) regimens (IFI-50 and IFI-60 Gy) in patients with unresectable locally advanced esophageal squamous cell carcinoma (ESCC) receiving chemoradiotherapy plus immunotherapy.
Materials/Methods: We conducted a retrospective analysis of 595 patients with locally advanced ESCC from 12 cancer centers across China. Patients were categorized into three radiotherapy groups: 1. IFI-50: involved-field irradiation delivering 50–50.4 Gy in 25–28 fractions to the planning target volume (PTV) or nodal PTV (PTV-N); 2. IFI-60: involved-field irradiation delivering 60 Gy in 30 fractions to PTV/PTV-N; 3. SIB: simultaneous integrated boost delivering 60–61.6 Gy to the primary gross tumor volume and 50.4–54 Gy to PTV/PTV-N in 28–30 fractions. Propensity score matching (PSM) was performed using the nearest neighbor method in a 1:1:1 ratio with a caliper width of 0.2. The primary endpoints of the study were overall survival (OS) and progression-free survival (PFS).
Results: The PSM cohort comprised three groups, each including 126 patients, with no statistically significant differences in baseline clinicopathological data (P > 0.05), and all covariate standardized mean difference values were below 0.1. Survival analysis results suggested that the SIB group demonstrated significantly superior OS compared with both IFI groups (vs. IFI-50, ?² = 16.150, P < 0.001; vs. IFI-60, ?² = 6.943, P = 0.008), and the IFI-50 group exhibited significantly worse PFS than both the SIB (?² = 7.235, P = 0.007) and the IFI-60 (?² = 4.612, P = 0.032) groups. Multivariate Cox analysis confirmed the SIB regimen was an independent favorable prognostic factor for OS (HR = 0.499, 95% CI = 0.308-0.809, P = 0.005) and PFS (HR = 0.633, 95% CI = 0.436-0.918, P = 0.016) compared with the IFI-50 regimen. Notably, in the immunotherapy followed by concurrent chemoradiotherapy (IC-CRT) group, patients receiving SIB demonstrated significantly better OS (?² = 9.425, P = 0.009), while patients receiving IFI-50 exhibited significantly poorer PFS (?² = 7.880, P = 0.019). No significant differences were observed among the three groups for OS and PFS within the concurrent immunochemoradiotherapy group (OS, ?² = 3.855, P = 0.146; PFS, ?² = 3.686, P = 0.158) or in the immunotherapy consolidation following concurrent chemoradiotherapy group (OS, ?² = 3.846, P = 0.146; PFS, ?² = 0.437, P = 0.804). Additionally, no significant differences in treatment-related toxicities were observed among the three groups (P > 0.05).
Conclusion: Uniformly escalating the radiotherapy dose to 60 Gy is not an effective strategy for patients with locally advanced ESCC. Among IC-CRT patients, the SIB regimen demonstrates the most significant survival advantage, providing crucial evidence for optimizing radiotherapy strategies in the era of “radio-immunotherapy synergy”.