Grade 4 radiation dermatitis presenting with full-thickness ulcerations of the groin after radiation therapy for anal squamous cell carcinoma (SCC): An example of the “bolus effect” of radiation therapy

M odern radiotherapy techniques for the treatment of squamous cell carcinoma (SCC) of the anus have led to a significant reduction in the incidence and severity of skin toxicity. However, grade 4 radiation dermatitis remains a difficult complication of radiation therapy for malignancies located in skin folds, a phenomenon known as the ‘‘bolus effect.’’ We describe a case of grade 4 radiation dermatitis in an HIV-positive patient after intensity-modulated radiation therapy (IMRT) for SCC of the anus, along with the management of these lesions.