apy, 6 were operated on at other hospitals, 4 discontinued CI-1040 PD184352 radiotherapy because of poor performance, 1 refused completion of radiotherapy, 2 died of complications during radiotherapy including aspiration pneumonia and tumor progression, 2 were not followed up after radiotherapy, 4 were treated with a chemotherapy regimen other than TMZ, 3 had pathologic features of glioblastoma with oligodendroglial components, and 1 was excluded because of pediatric age. Two pathologists independently examined the specimens. All patients were followed up until death or time of analysis. The median follow up period was 22 months, and the median age was 58 years. The sex distribution showed a male preponderance. Karnofsky performance status at the beginning of radiotherapy was over 60% in 84 patients.
All patients underwent surgery after imaging studies. Treatment Gross total resection was achieved in 39 patients. Subtotal resection or partial removal was performed in 30 and 17 patients, respectively. In 7 patients, only biopsy was performed. Three dimensional conformal radiotherapy was used to treat 86 patients with 2 Gy per fraction. Seven patients were treated with intensity modulated radiation therapy using tomotherapy with 2.5 Gy per fraction. The definition of subtotal resection was resection of a gross tumor by 75% or more. Partial resection was defined as resection of a gross tumor by less than 75%. Postoperative radiotherapy was started 10 to 67 days after operation. We wanted to begin radiotherapy within 2 weeks of operation, and postoperative radiotherapy was started within 3 weeks of operation in 87% of the patients.
Patients were treated with thermoplastic immobilization masks to ensure adequate immobilization during therapy and reproducibility. We followed the protocol of Radiation Therapy Oncology Group 98 03 trial to define the target volume for radiotherapy. The gross tumor volume included the resection cavity, and any gross residual tumor was observed with immediate postoperative magnetic resonance imaging. A 1.5 cm margin was added to the GTV for microscopic extension, and an additional 0.3 cm margin was added for setup uncertainty. A subsequent boost was given to PTV2, which was defined as the GTV plus a 0.3 cm margin. The total dose of radiotherapy was 50 to 74 Gy. We gradually increased the radiotherapy dose from 60 Gy to 70 Gy until 2005, thus, most patients received 66 Gy.
Forty nine patients received 70 Gy. Three patients received 60 Gy. The current standard regimen is radiotherapy plus continuous daily TMZ, followed by six cycles of adjuvant TMZ. Since December 2006, 54 patients received TMZ chemotherapy with this current standard regimen. In 39 patients treated before 2006, the TMZ regimens were different from the current standard regimen in daily dose, administration days, and adjuvant TMZ regimen. Inconsistent TMZ regimens that were different from the current standard included TMZ with other chemotherapy agents, TMZ administered after radiotherapy, TMZ daily dose different from the current standard TMZ treatment, and TMZ administered concurrently with radiotherapy, but not daily during radiotherapy. MGMT gene promoter methylation assessment A retrospective analysis evaluated the MGMT gene promoter methylation status. Genomic DNA