Comparative study between simultaneous integrated and sequential boost using intensity-modulated radiotherapy for esophageal carcinoma

Abstract

Objective To compare the clinical efficacy between simultaneous integrated boost (SIB) and sequential boost (SB) using intensity-modulated radiotherapy (IMRT), and investigate the long-term clinical efficacy and adverse events of SIB-IMRT in combination with chemotherapy in the treatment of esophageal cancer. Methods Clinical data of 330 patients diagnosed with esophageal cancer undergoing radical chemoradiotherapy in Fourth Hospital of Hebei University from January 2006 to December 2015 were respectively analyzed. All patients were assigned into the SIB-IMRT (n=135) and SB-IMRT groups (n=195). All patients received definitive radiotherapy with elective nodal irradiation (ENI). After the propensity score matching (PSM), 105 patients were enrolled in each group. Kaplan-Meier method was used to survival analysis. Cox model was used to multivariate prognostic analysis. Results Prior to PSM, the 1-, 3-and 5-year local control rates were 80.1%, 58.3%, 46.7% and 72.1%, 44.9%, 40.5% in the SIB-IMRT and SB-IMRT groups (P=0.050), and the 1-, 3-and 5-year OS rates were 81.4%, 51.9%, 43.5% and 80.5%, 37.9%, 22.3%(P=0.014), respectively. After the PSM, the 1-, 3-and 5-year LC rates were 80.2%, 54.2%, 43.9% and 75.5%, 47.2%, 41.2%(P=0.264), and the 1-, 3-and 5-year OS rates were 78.9%, 49.0%, 40.8% and 83.3%, 41.7%, 24.8%(P=0.265), respectively. Multivariate analysis demonstrated that TNM staging was an independent prognostic factor in the SIB-IMRT group, whereas TNM staging and chemotherapy served as the independent prognostic factors in the SB-IMRT group. Stratified analysis revealed that the LC rate in the SIB-IMRT was significantly higher than that in the SB-IMRT group when radiotherapy alone was performed (P=0.018). The OS rate in the SIB-IMRT group was equally higher compared with that in the SB-IMRT group. Conclusions The LC and OS rates are almost identical after SB-IMRT and SIB-IMRT in the treatment of esophageal cancer, whereas the prognostic survival in the SIB-IMRT group is significantly longer compared with that in the SB-IMRT group during radiotherapy alone. The findings remain to be validated by multi-center investigations with a large sample size. Key words: Esophageal neoplasms/intensity-modulated radiotherapy; Simultaneous integrated boost; Sequential boost; Prognosis