Comparison of Treatment Results of Malignant Astrocytoma after post-op Radiotherapy Alone or post-op Concurrent Chemoradiotherapy plus Adjuvant chemotherapy-Experience in TSGH

Abstract

Purpose: To analyze the treatment results of malignant astrocytoma after radiotherapy alone or concurrent chemoradiotherapy plus adjuvant chemotherapy in TSGH. Methods and Materials: From April 2002 to December 2007, we identified 35 patients with documented, histologically confirmed, previously untreated glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA). They were treated with surgical resection followed by radiotherapy alone or chemoradiotherapy in our hospital. A total of 60 Gy was given in 6 weeks with 3D conformal RT (3D-CRT). Fusion of planning CT with MRI was routinely used to assist target delineation. We used concomitant temozolomide (75 mg/m^2 daily up to 49 days) followed by up to six cycles of adjuvant temozolomide (150 to 200 mg/m^2 daily for five days, every 28 days). Follow-up and survival times were calculated from the date of diagnosis to the date of last contact or death. Disease-free survival (DFS) and overall survival (OS) were computed by Kaplan-Meier methods. Results: The median follow-up was 19.1 months. At the time of analysis, 10 patients were alive, 25 patients had died. The median survival rate was 19.1 months for all patients. The 3-year overall survival rates were 14% and 43% in radiotherapy alone arm and CCRT arm, respectively. (p=0.002). The 3-year progression-free survival rates were 10.6% and 13.9% in radiotherapy alone and CCRT arm, respectively. (p=0.54). In the AA group, the overall survival rates were 8.7% and 67.9% in radiotherapy alone arm and CCRT arm, respectively. (p=0.001). In the GBM group, the overall survival rates were 16.3% and 23.7% in radiotherapy alone and CCRT arm, respectively. (p=0.261). In-field failure was the major cause of failure, among 35 patients, 22 (62.8%) patients had in-field failure. All patients completed radiotherapy courses. Thirty (86%) patients had grade 1 CNS toxicity and 5 (14%) patients had grade 2 CNS toxicity. Among 21 patients who received temozolomide, 18 patients had no obvious side effects during and after chemotherapy. Conclusions: Addition of adjuvant chemotherapy with temozolomide to radiotherapy for patients with newly diagnosed AA and GBM has statistically significant survival benefit especially for patients of AA with tolerable toxicity.