Hypofractionated Radiation Therapy in Keratinocyte Carcinoma

Hypofractionated radiation therapy regimens are well suited to the management of keratinocyte carcinomas. Most lesions are small, superficial and not close to critical organs at risk. Fewer visits to the cancer centre are advantageous for the frail and elderly patient population. No difference in cosmesis or local control has been found when comparing hypofractionated with conventionally fractionated radiation therapy schedules, although most of the data in the literature are retrospective, highlighting the need for prospective trials. As keratinocyte carcinomas can present anywhere on the skin surface, a wide variety of techniques may be used to optimise treatment delivery, including external beam radiation with kilovoltage, electron beams and megavoltage photons. Brachytherapy can also be used with radionuclide and electronic-based applicators, surface applicators and interstitial techniques for lesions >5 mm deep. Stereotactic body radiotherapy, or extreme hypofractionation, is an emerging treatment option that delivers an ablative dose to the tumour while minimising dose to organs at risk through precision planning and delivery techniques. Frail elderly patients with medically inoperable disease not suitable for conventionally fractionated radiation therapy may achieve durable locoregional control with dose escalation. Ongoing studies following local control and toxicity are warranted. The aim of this article is to provide clinical oncologists with an overview of hypofractionation for keratinocyte carcinomas.