Objective:The aim of the study was to retrospectively evaluate the outcomes and important prognostic factors for patients with high-grade gliomas(HGG)treated with conventionalradiotherapy(RT)followed by IMRT as a boost in comrnbination with chemotherapy.Methods:From November 2004 to November 2006,112 consecutive patients with high-grade rngliomas were treated with radiotherapy,which included initial conventional radiotherapy and an IMRT boost to a total dose rnof 57.5-62.5 Gy,with 27-29 fractions delivered over 37-45 days.All cases received 3-6 cycles of chemotherapy,63 cases rnreceived temozolomide,and another 49 cases received methyl-CCNU and teniposide.The acute and late treatment toxicities and the patterns of treatment failure were recorded.The overall survival(OS)rate and progression-free survival(PFS)rate were calculated,and the prognostic factors were analyzed.Results:Most of the acute radiation reactions were grade 1 or 2.No grade 4 acute reactions were noted.Three cases developed radiation necrosis.Grades Ⅰ,Ⅱ,and Ⅲ myelosuppressions were observed in 5,32,and 12 cases of 49 patients treated with teniposide and methyl-CCNU,respectively.Grades Ⅰ and Ⅱmyelosuppressions were observed in 15 and 3 of the 63 patients who were treated with temozolomide,respectively.The 57 cases(50.9%)had recurred locally,and 13 cases(11.6%)had intracranial dissemination.The OS rates at 1,2,and 3 years were 78.9%,54.7%,and 30.8%,respectively.The PFS rates at 1,2,and 3 years were 63.8%,38.9%,and 10.5%,respectively.A multivariate analysis showed that only tumor location and KPS were prognostic factors of OS.These same two variables and histopathology were statistically significant predictive factors in a multivariate analysis for PFS.Conclusion:Radiation toxicities were not found to be increased in this retrospective study with 112 consecutive patients of combined modality therapy including an IMRT boost treatment for HGG.Higher rate of local regional dissemination within the brain was observed than before.Tumor location,histopathology and KPS were important prognostic factors.