Abstract & Overview
The importance of fractionation in radiotherapy has been known since the early days of radiobiology. Certain tumors, such as head and neck, are radiobiologically challenging because of several factors contributing to treatment failure, including hypoxia, cellular kinetics, and proportion of cancer stem cells. The management of the above factors often requires different, more aggressive approaches, which led to the design of altered fractionation schedules. Despite these unconventional treatment regimens, the clinical outcome of head and neck cancer patients has not significantly improved. Therefore, there is the need for combined modality treatments employing chemo- and/or immunotherapy. Furthermore, proton therapy and hadrontherapy are trialed in this patient group to elucidate their advantage over conventional techniques. This article discusses all the above aspects in the context of fractionation and also the evolution and impact of fractionated regimens on the clinical outcome of head and neck cancer patients.