Failure of radiation therapy in orbital xanthogranuloma

Purpose: The efficacy of radiation therapy in orbital xanthogranuloma in patients who fail medical therapy is unclear. The purpose of this study was to ascertain its effectiveness. Methods: The records of 11 cases were reviewed retrospectively for histopathologic findings, age, gender, site of involvement, clinical manifestations, and outcomes of treatment. The case histories of the 4 patients treated with radiation, all of whom had failed medical treatment, were described. Results: Of 11 patients, 5 were female, and all were white. The age range at the time of presentation was 25 to 85 years. Nine patients had bilateral involvement. Five patients, all of whom had bilateral disease, had systemic manifestations or autoimmune disease thought to be related to their orbital disease. In general, patients treated with systemic corticosteroids had at least a partial response of their lesion. However, none of the 4 patients treated with orbital radiation (3 of whom had not responded to steroid treatment and 1 of whom had responded only to high-dose steroids) experienced improvement, and at least 3 experienced exacerbation of their disease. The histologic features before treatment in all cases were similar and consistent with xanthogranuloma. Conclusion: Orbital xanthogranuloma may be a unilateral or bilateral condition. Particularly when bilateral, it may be associated with similar lesions elsewhere or with systemic autoimmune disorders. The results of this study suggest that fractionated radiotherapy not only may be ineffective but also may exacerbate the progression of the orbital lesions in patients who do not respond to medical therapy or who are steroid dependent on intolerable doses of medication.