Hyperfractionated and accelerated-hyperfractionated radiotherapy for glioblastoma multiforme

Because of promising radiobiological advantages allowing close escalation a nd/or reduction of treatment time, hyperfractionated and accelerated-hyperf ractionated radiotherapy (hf-rt, ahf-rt) were introduced as part of treatme nt of glioblastoma multiforme (gbm). In December 1988 we started a prospect ive study of hf-rt(to;tal dose 78 Gy, two daily fractions of 1.3 Gy, interv al between daily fractions 6 hr, treatment time 6 weeks, n = 34 patients). The results were compared with our previous regimen of conventionally fract ionated radiotherapy (cf-rt: total dose 60 Gy, single dose 2 Gy,treatment t ime 6 weeks, n = 32 patients). In June 1990, the protocol was modified in o rder to reduce treatment time (ahf-rt: total dose 60 Gy; two daily fraction s of 1.5 Gy, interval 6 hr, treatment time 4 weeks, n = 92 patients until D ecember 1996). No chemotherapy was given. Entry criteria were: age greater than or equal to 17 years, pathological diagnosis of supratentorial gbm, an d no previous treatment other than surgery. The ahf-rt group included signi ficantly more patients with previous surgical resection instead of biopsy o nly. Com:pared with the cf-rt group, both the hf-rt and the ahf-rt group in cluded significantly more patients with frontal tumor location. We found no significant survival difference between the groups (median survival 7-10 m onths, I-year survival rate 19%-29%). Progression-free survival, clinical c ourse, and toxicity were also not significantly different. Karnofsky perfor mance status, age, and corticosteroid dose during radiotherapy were the mos t important prognostic factors. The results of this trial are in large agre ement with most previous publications. It demonstrated no improved survival . However, it showed that treatment time can be reduced by ahf-rt without l oss of survival benefit or intolerable toxicity. A short radiotherapy cours e might be appropriate for many patients with gbm who :are not suitable for rather aggressive investigational therapies. (C) 1999 Wiley-Liss, Inc.