Actinic keratosis in the most common premalignant keratotic tumour of sun-e
xposed skin. A 66-year-old man developed a large actinic keratosis on his s
calp, which did not respond to conventional treatment. Fractionated radioth
erapy with a cumulative dose of 28 Gy resulted in complete remission withou
t relapse during a 14-month follow-up. In older subjects in whom convention
al treatment fails, low-dose fractionated radiation therapy is an effective
alternative method.