Management of Skin Reactions

Abstract

The skin is the largest organ in the body and one of the most visible targets for assessing radiotherapy-induced reactions. In the orthovoltage era, the dose at which skin reaction occurred was taken as a measure of dose fractionation and for calculation of NSD. The advantage of megavoltage beams lies in their ability for skin sparing. Factors affecting skin reactions include total radiotherapy dose delivered, fraction size, volume of field treated, use of radiosensitizers (such as chemotherapy drugs, e.g. Adriamycin, cisplatin, gemcitabine) as well as volume of normal structures involved. The most sensitive cells are those lining the hair follicles because of the limited number of cells in the functional subunits (FSUs) and hence its limited reparative potential compared to the skin. Thus, after the start of radiotherapy, the first reaction seen is alopecia. The main site of radiation damage to the skin is at the basal layer cells of the epidermis. The effects are not immediately seen but start occurring once the superficial layers have been shed when the damage has exceeded the regenerative potential of the basal layer. Skin reactions vary from mild erythema to moist desquamation and even ulceration.