Radiochemotherapy in Patients With Primary Glioblastoma Comparing Two Temozolomide Dose Regimens

Abstract

To evaluate toxicity and outcomes in patients with primary glioblastoma (GB) treated with postoperative radiochemotherapy (RCHT) with temozolomide (TMZ) comparing two dose regimens. A total of 160 patients with histologically confirmed GB were treated with postoperative RCHT with TMZ. Of the patients, 66 were female and 94 were male, with a median age of 60 years. After the primary diagnosis, a biopsy had been performed in 42 patients; a subtotal and total resection was conducted in 66 and 52 patients. Postoperative radiotherapy was applied with a median dose of 60 Gy with a median fractionation of 5 x 2Gy/week. Concomitant TMZ was prescribed at 50 mg/m(2) in 123 patients (Group A) and at 75 mg/m(2) in 37 patients (Group B). Patients were followed in 3-months intervals, with a median follow-up of 13 months. Overall survival (OS) rates in Group A vs. Group B were 67% and 79% at 1 year and 43% vs. 49% at 2 years, respectively (p = 0.69). Progression-free survival was 49% vs. 54% at 1 year and 22% vs. 29% at 2 years (p = 0.31). Hematologic toxicity was not statistically significant over the 6-week RCHT period except for a significant decrease in platelets during Week 6 (p = 0.01) in Group B. Overall survival seems to be comparable in both groups, although longer follow-up and a larger group of patients are needed to corroborate these results. Lower dosing of TMZ also is associated with a more beneficial toxicity profile.