Hyperfractionation is the use of large fractions smaller than standard dose per fraction per day.
The therapeutic advantages in hyperfractionation is a more rapid increase in tolerance with decreasing dose per fraction for late responding normal tissues than for tumours and increase in long-term local tumour control.
A single institutional phase III trial of preoperative chemotherapy with hyperfractionation
radiotherapy plus surgery versus surgery alone for resectable esophageal squamous cell carcinoma.
18,35,36) Clinically, radiation fractionation strategies have attempted to overcome tumor repopulation via hyperfractionation, in which smaller doses are given more frequently, or via accelerated fractionation protocols, in which the dosing schedule occurs at shorter intervals to achieve the total dose more quickly.
Hyperfractionation and accelerated fractionation protocols may improve response among tumors with high repopulation rates.
This technique is the basis of radiotherapeutic techniques, such as hyperfractionation
, which seeks to control tumors (with responses similar to the acute response tissues) without damaging the adjacent differentiated tissues.
Analysis of data from various hyperfractionation
studies reveals significant improvement in the tumor and overall survival.
Hyperfractionation typically refers to twice-daily delivery.
Accelerated hyperfractionation has also been studied as a way of increasing tumor-cell killing without increasing the risk of late complications.
, the total dose of radiation remains approximately the same as in standard therapy, but it is given in smaller doses 2 or 3 times per day.
Newer strategies of hyperfractionation
and accelerated fractionation lead to 7% to 10% improvement in locoregional control compared to once-daily treatment schemes.
4,5] Many strategies have been made trying to improve outcomes in locally advanced diseases such as uses of hypoxic cell sensitizers, hyperbaric oxygen, neutron therapy and hyperfractionation