Comparison of clinical efficacy and prognosis of intensity-modulated radiotherapy and three dimensional conformal radiotherapy in patients with stage Ⅱ/m esophageal cancer: a multi-center retrospective analysis in Beijing, Tianjin and Hebei province (3JECROG R-06) / 中华放射肿瘤学杂志

ABSTRACT

Objective To compare the therapeutic effects between three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in patients with stage Ⅱ/Ⅲ esophageal cancer and investigate the prognostic factors.Methods Medical record of 2 132 patients with stage Ⅱ/Ⅲ esophageal cancer who underwent definitive radiotherapy with/without chemotherapy in 10 hospitals from January 2002 to December 2016 from were retrospectively analyzed.Among these patients,37.9％ of them were aged ≥ 70 years,33.9％ with neck and upper esophageal tumors and 66.1％ with middle and lower esophageal and borderline tumors.The median gross tumor volume (GTV) and lymph node gross tumor volume (GTVnd) was 41.6 cm3.Among them,32％ were stage Ⅱ] and 68％ were stage Ⅲ.A total of 723 patients received 3DCRT and 1 409 cases received IMRT.Patients received an equivalent dose in 2 Gy (EQD2) ≥ 60 Gy accounted for 86.1％,and 41.1％ of them received concurrent chemoradiotherapy.Results The median follow-up time was 60.8 months.The 1-,3-and 5-year overall survival (OS) of all patients was 73.9％,41.7％ and 32.6％,and the 1-,3-and 5-year progression-free survival (PFS) was 62.2％,37.3％ and 32％,respectively.Multivariate analysis demonstrated that age,primary tumor location,clinical stage,tumor target volume,EQD2 and concurrent chemoradiotherapy were the independent prognostic factors for OS.Age,primary tumor location,clinical stage,tumor target volume and EQD2 were the independent prognostic factors for PFS.The OS and PFS did not significantly differ among the low-risk,low-/moderate-risk,moderate-/high-risk and high-risk groups according to age≥70 years,tumor diameter＞5 cm,tumor volume ≥41.6 cm3 and stage Ⅲ (P＜0.001).After the propensity score matching (PSM) method,neither 3DCRT nor IMRT yielded significant advantages in OS or PFS (P=0.971;P=0.658).However,IMRT tended to yield survival benefits in low-risk patients (P=0.125).Conclusions Both 3DCRT and IMRT yield relatively high OS rate in patients with stage Ⅱ/Ⅲ esophageal cancer.The prognosis model established in this investigation can properly predict the survival of patients.Low-risk patients tend to obtain survival benefits from IMRT.