Radiotherapy of lymphoid diseases of the orbit.

Thirty-two patients with orbital pseudotumor (18), reactive lymphoid hyperplasia (2), atypical lymphoid infiltrate (4) or malignant lymphoma (8) were treated in the Division of Radiation Therapy at Stanford University between January 1973 and May 1983. Of the 20 patients with pseudotumor or reactive lymphoid hyperplasia, 10 had unilateral lesions and 10 had bilateral lesions. Biopsy samples were obtained in 15 patients; in five patients with bilateral disease the diagnosis was made on the basis of computed tomography (CT) and clinical findings. The majority of patients were referred because of disease refractory to treatment with corticosteroids. The patients were given a mean dose of 2360 rad using complex, individualized megavoltage techniques including lens shielding. Radiotherapy was well tolerated with no significant acute or late complications. Fifteen patients had complete resolution of symptoms after treatment; five had continued symptoms. Of the 12 patients with malignant lymphoma or atypical lymphoid infiltrate, four had systemic lymphoma with orbital involvement and eight had orbital involvement only. The diagnosis was made by biopsy in all patients and immunophenotyping was done in six cases, of which 5 were monoclonal. Patients were evaluated with a chest radiograph, lymphogram or abdominal CT, bone marrow biopsy and orbital CT. A mean dose of 3625 rad was delivered to the orbit only. Most of the patients received complex megavoltage treatment using bolus. All patients in this group had a complete response and local control. There were no relapses in those with localized disease. Two patients developed cataracts. Carefully planned orbital radiotherapy provides local control without symptomatic sequelae for orbital masses ranging from pseudotumor to malignant lymphoma.