Enhanced mucosal reactions in AIDS patients receiving oropharyngeal irradiation.

The oropharynx and hypopharynx are common sites of involvement in AIDS patients with mucocutaneous Kaposi's sarcoma. The radiotherapist is often asked to intervene with these patients due to problems with pain, difficulty in swallowing, or impending airway obstruction. We have noted an unexpected decrease in normal tissue tolerance of the oropharyngeal mucosa to irradiation in AIDS patients treated in our department. Data on 12 patients with AIDS and Kaposi's sarcoma receiving oropharyngeal irradiation are presented here. Doses ranged from 1000 cGy to 1800 cGy delivered in 150-300 cGy fractions. Seven of eight patients receiving doses of 1200 cGy or more developed some degree of mucositis, four of these developed mucositis severe enough to require termination of treatment. All patients in this study received some form of systemic therapy during the course of their disease, but no influence on mucosal response to irradiation was noted. Four patients received total body skin electron treatments, but no effect on degree of mucositis was seen. Presence or absence of oral candidiasis was not an obvious factor in the radiation response of the oral mucosa in these patients. T4 counts were done on 9 of the 12 patients. Although the timing of the T4 counts was quite variable, no correlation with immune status and degree of mucositis was found. The degree of mucositis seen in these patients occurred at doses much lower than expected based on normal tissue tolerances seen in other patient populations receiving head and neck irradiations. We believe that the ability of the oral mucosa to repair radiation damage is somehow altered in patients with AIDS.