PURPOSE: To evaluate the toxicity and efficacy of chemoradiotherapy with temozolomide (TMZ) administered in an intensified 1-week on/1-week off schedule plus indomethacin in patients with newly diagnosed glioblastoma. PATIENTS AND METHODS: A total of 41 adult patients (median Karnofsky performance status, 90%; median age, 56 years) were treated with preirradiation TMZ at 150 mg/m(2) (1 week on/1 week off), involved-field radiotherapy combined with concomitant low-dose TMZ (50 mg/m(2)), maintenance TMZ starting at 150 mg/m(2) using a 1-week on/1-week off schedule, plus maintenance indomethacin (25 mg twice daily). RESULTS: The median follow-up interval was 21.7 months. Grade 4 hematologic toxicity was observed in 15 patients (36.6%). Treatment-related nonhematologic Grade 4-5 toxicity was reported for 2 patients (4.9%). The median progression-free survival was 7.6 months (95% confidence interval, 6.2-10.4). The 1-year survival rate was 73.2% (95% confidence interval, 56.8-84.2%). The presence of O(6)-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation in the tumor tissue was associated with significantly superior progression-free survival. CONCLUSION: The dose-dense regimen of TMZ administered in a 1-week on/1-week off schedule resulted in acceptable nonhematologic toxicity. Compared with data from the European Organization for Research and Treatment of Cancer/National Cancer Institute of Canada trial 26981-22981/CE.3, patients with an unmethylated MGMT gene promoter appeared not to benefit from intensifying the TMZ schedule regarding the median progression-free survival and overall survival. In contrast, data are promising for patients with a methylated MGMT promoter. (c) 2010 Elsevier Inc. All rights reserved.