[Therapeutic gain factor of multiple fractions per day]

Treatment with multiple fractions per day would be expected to offer a significant therapeutic gain. Clinical benefits from the therapeutic gain, however, depend on the steepness of dose-response curves for the tumor control. We discussed the therapeutic gain factor of hyperfractionation and accelerated fractionation in head and neck cancer and malignant glioma, and also discussed the impacts of this factor on the local control of the tumors.