Feasibility of multiple daily fractionation in high dose radiotherapy of malignant gliomas

Experimental data suggest that the tolerance of the central nervous system to fractionnated radiotherapy is determined mainly by the cellular repair processes, while little or not tissue repopulation occurs during periods of up to 6 weeks. This would mean that the overall time of radiotherapy to the brain could be reduced without affecting the tolerance, providing that the interval between irradiations is long enough to allow full cellular repair. In view of these facts, a radiotherapy scheme with three irradiations of 2 GY per day to a total dose of 30 GY in one week was tested in high grade malignant gliomas. The course was repeated after 3 to 4 weeks to a total tumour dose of 60 GY. The aim of this study was to evaluate the acute tolerance to such a treatment schedule. The advantage to the patient is a reduced burden as result of shorter treatment periods. The acute tolerance in 15 patients was excellent. Of the patients irradiated postoperatively, 70 % did not even require steroid administration during radiotherapy