RESUMO
Oral, pharyngeal and esophageal infections caused by Candida species occur very frequently when it comes to radiation therapy for head and neck cancer. In clinical terms oral candidosis is most often characterized by pseudomembranes or erythema. The erythematous form of oral candidosis has in particular to be distinguished from radiation mucositis. Candidosis of the oral and gastrointestinal tract often causes interruption of therapeutic radiation. Ketoconazole treatment is able to reduce the period of time during which the patient cannot be treated by radiation. Oral ketoconazole given at a daily dose of 200 mg is moreover superior to topical nystatin. To date, however, it is not yet clear if patients who have head and neck cancer in whom radiation therapy has to be started would profit from the prophylactic application of ketoconazole from start on.