During 4 years (1993 - 1997) 45 patients (pts) with a mean age of 21 years (range 5 to 49 years) were treated by stereotactic fractionated therapy (SRT) (5 fractions on 5 consecutive days). There were low grade gliomas grade I in 20 patients and grade II in 25 patients. For imaging authors used magnetic resonance including T1 (post-contrast), T2 and PD sequences. The median target volume was 3 500 cmm (range from 200 to 25 000 cmm). The median minimal dose applied to the periphery was 22,5 Gy (ranged from 23 to 30 Gy). All patients were followed up clinically and by CT or MRI every 6 months first two years after SRT, then every 12 months. Complete and partial regression (CR, PR) was observed in 34 (75%), stabilization in 8 (18 %) and local progression in 3 (7%) patients. All CR, PR had relatively long latent periods with a median of 18 months (range from 8 to 48 months). Four patients had asymptomatic and reversible enlargement of the pathological volume from 6 to 9 months after SRT. One patient with repeated stereobiopsy which proved grade II - III died from local progression 10 months after SRT. 44 patients are still alive with minimal follow up 26 months after SRT and median survival 38 months (ranged from 26 to 80 months). A larger number of treated patients is needed to find proper indication criteria, the optimal level of doses and fractionation pattern with acceptable late toxicity.

        Key words: low grade gliomas - stereotactic irradiation - fractionation pattern - acute and late toxicity