Efficacy and Prognostic Analysis of 315 Stage I-IVa Esophageal Cancer Patients Treated with Simultaneous Integrated Boost-Intensity-Modulated Radiation Therapy

Purpose: Use of simulated integrated boost-intensity-modulated radiation therapy (SIBIMRT) is rarely reported in the treatment of esophageal cancer. This study was performed to observe the curative effect and prognostic factors associated with concurrent chemoradiotherapy for esophageal cancer using modern radiotherapy (RT) techniques. Patients and Methods: In total, 315 patients with esophageal squamous cell carcinoma who received SIB-IMRT between 2015 and 2018 were included in this retrospective study. Median doses were planning target volume (PTV) 5400 cGy, 30 times (180cGy/fraction); planning gross tumor volume (PGTV) 6000 cGy, 30 times (200 cGy/fraction), once a day and 5 times a week. The entire period of RT was 6 weeks. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse reactions were observed. Univariate analysis was performed, and factors with P<0.15 were included in multivariate analysis. Cox regression analysis was used for multivariate prognostic analysis. P<0.05 was considered statistically significant. The incidence of adverse reactions under single chemotherapy concurrent chemoradiotherapy (sCCRT) and double chemotherapy concurrent chemoradiotherapy (dCCRT) was analyzed. Results: Two-year, 3-year OS and PFS of the entire group were 49.5%, 40.2% and 40.3%, 34.0%, and the median survival time was 23.5 months. Univariate and multivariate analyses showed that T-stage (P=0.049), N-stage (P=0.024), clinical stage (P=0.041), short-term efficacy (P<0.001), and use of concurrent chemotherapy (P<0.001) were the influencing factors for OS. ORR was 87.6%. Adverse reactions were significantly increased with increasing chemotherapy dose. Conclusion: The adverse reactions of SIB-IMRT in esophageal cancer can be tolerated. T-stage, N-stage, clinical stage, short-term curative effect, and concurrent chemotherapy are the prognostic factors affecting survival. Because it has lower toxicity and is as effective as dCCRT, sCCRT should be considered in the management of esophageal cancer.