Background:There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China.We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage Ⅰ EC using in-house made multi-channel applicators (IH-MCA) in a single institution.Methods:Three hundred and ninety patients with stage Ⅰ IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015.All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after extal beam radiotherapy (EBRT).The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT.Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment.The Kaplan-Meier method was used to calculate survival rate.Results:Follow-up rate was 92.8％ and the median follow-up time was 48 months (range 4-172 months).The 5-year overall survival (OS),progression-free survival,local recurrence,and distant metastasis rates for all patients were 96.3％,92.1％,2.9％,and 4.8％ respectively.Two patients had isolated relapse in vagina outside the irradiated volume.The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio:0.368,95％ confidence interval [CI]:0.131-1.035,P =0.048;hazard ratio:0.576,95％ CI:0.347--0.958,P =0.026,).Conclusions:For patients with IR to HR stage Ⅰ EC,adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates.Age and grade were the prognostic factors correlated with OS.