Local control of high-grade gliomas with limited volume irradiation versus whole brain irradiation

Introduction: To evaluate the role of limited field radiation therapy in the management of high-grade gliomas and glioblastoma multiforme (GBM). Material and Methods: From July '96 to January '98, 50 newly diagnosed patients of high-grade gliomas (Grade III and IV) and glioblastoma multiforme who underwent surgery in the form of partial, sub-total or near-total excision as the primary treatment were enrolled in this study. The patients were randomized to receive two different postoperative external radiation protocols, Study Group A: Localized field external radiotherapy 50 Gy/25#/5 wks followed by Boost 10 Gy/5#/1 wk, Control Group B: Whole brain external radiotherapy 40 Gy/20#/4 wks followed by Boost 20 Gy/10#/2 wks by localized field. Results: 20/25 (80%) patients in the study group and 14/25 (56%) patients in the control group showed improvement in their Karnofsky Performance Status (KPS). Thus a significant difference in the performance status was noted in favor of limited field irradiation. No significant difference in the local response was seen between the two groups after radiotherapy. Six months progression-free survival of the study group was 44% as compared to 26% in the control group. Six months overall survival was 66.67% in the study group and 50.72% in the control group (P<0.01). Maximum recurrences were noticed within 2 cm of the original tumor margin in both the groups. Conclusions: Although local control and survival of the patient in both the groups were same, performance status definitely improved in patients treated with localized field irradiation only.

Keywords
Brain tumors, High-grade gliomas, Localized field, External radiation therapy.