Long Term Radiation Consequences

This month we presented a case of radiation dermatitis some 20+ years following radiation treatment of skin carcinoma. This case had the classic presentation of a dry ulcer surrounded by atrophic hypopigmented skin. Clearly, incisional biopsy is recommended to differentiate this from a delayed radiation-induced malignancy. This delayed presentation of radiation dermatitis is unusual and likely contributed by aggressive dosing regimen.

Both acute radiation dermatitis and delayed effects can be minimized by using lower dose per fraction and spreading out the total treatment over a longer period of time with more fractions. Acute radiation dermatitis is expected with skin cancer treatment and is characterized by erythema, crusting, and ultimately ulceration. The greater the degree of acute radiation dermatitis – the greater the probability of poor cosmetic outcome with radiation – skin atrophy, hypopigmentation, and dermal sclerosis.

Late skin breakdown as has occurred in our case is rare and must be differentiated from a malignancy. A potential contributing reason for the late effect is progressive devascularization of the treatment area resulting in a dry avascular ulcer. Other causes may include continued smoking, aging related atrophy, or surgical intervention. Two caveats in these settings: be wary of secondary malignancies presenting as radiation ulcers and avoid extensive surgery, as healing will be impaired.

There is a built-in paradox with these presentations – a biopsy is necessary to rule out a carcinoma, but the larger the biopsy – the larger the nonhealing wound created by it. Patients need to be warned of this likely outcome. In fact, the biopsy can create a larger nonhealing wound than the ulcer at presentation. Two alternative options exist for the clinician – observation of the lesion or complete excision of the radiation damaged skin. Neither may be practical for the patient.

As for the patient presented here, a subsequent incisional biopsy was performed, removing 3/4 of the visibly radiated skin. Complete excision could not be done due to reluctance to undergo a large reconstruction in this patient. As predicted, the closure promptly broke down 5 days post-op due to tension and poor vascularity. The wound is now a larger dry ulcer healing slowly. The patient is happy with negative biopsy and is not bothered by the outcome.