To evaluate results, prognostic tactors and patterns ot tailure ot the postoperative radiotherapy (PRT) tor Low-Grade Gliomas (LGG). Methods:• Setween 1985 and 1995, 158 patients with LGG (WHO II) received PRT. There .were 116 astrocytomas, 17 mixed oligoastrocytomas, 25 oligodendrogliomas. Median age was 39 years (range: 17-74).
Conventional treatment techniques and doses were employed (median total dose-58 Gy, median dose per traction -2 Gy). Ali known parameters with possible intluences on prognosis were analysed in univariate analysis (UA). Then a multivariate analysis (MA) was performed tor variabies with significance level p<0.2 in UA. CT seans taken prior to initial surgery and at the time ot recurrence have been compared to define the recurrence pattern in relation to the initial tumour site. Initial and recurrent tumour were drawn in the simulator films in order to precise the tailure pattern in relation to irradiated volume. Survival after recurrence (SAR) was analysed using Kaplan-Meier method and prognostic tactors were analysed using logrank test.
Results: The minimum tollow-up period tor alive patient was 52 months. The 5-and 10-year actuarial overall survival rate were 55-and 41 % respectively. The actuarial progression tree survival rate were 48% and 29% tor 5 and 10 years respectively. MA revealed that good WHO performance status (p=0.00001), duration ot