RADIOTHERAPY IS SUCCESSFUL TREATMENT FOR ORBITAL LYMPHOMA

Purpose: To describe the clinical presentation, treatment technique, o utcome and complications in a large single institutional experience us ing radiotherapy for treatment of orbital lymphoma. Methods and Materi als: Twenty-five patients with lymphoma of the orbit or ocular adnexa were treated with radiotherapy at Stanford University Medical Center d uring the fourteen year period, 1977-1991. Patients were staged using the Ann Arbor criteria with chest x-ray, computerized tomography of ab domen and orbits, lymphangiogram, and bone marrow biopsy. Patients wit h disease localized to the orbits as well as those with disseminated d isease and symptomatic orbital lesions were treated. Thirty-one involv ed eyes were treated. Mean radiotherapy dose was 35.3 Gy, with a range of 28 Gy to 40.2 Gy. Lens protection was used in all cases. Two patie nts with diffuse large cell lymphoma also received chemotherapy as par t of their initial treatment. Follow-up ranged from 10 months to 13 ye ars, with a mean follow-up time of 4 years. Results: Twenty patients h ad disease confined to one or both orbits (Stage I). One patient had a monoclonal atypical infiltrate, while the remainder had a histologic diagnosis of malignant lymphoma: diffuse small lymphocytic, 13; follic ular mixed, 3; diffuse small cleaved, 3; diffuse large cell, 2; follic ular small cleaved, 1; follicular and diffuse small cleaved, 1; undiff erentiated, 1. Two local relapses occurred; the actuarial 5-year freed om from local relapse is 89%. Actuarial 5-year freedom from distant re lapse, freedom from any relapse and overall survival are 77%, 70%, and 93%, respectively. Acute complications of treatment were mild. Late c omplications included transient cystoid macular edema (one patient), a symptomatic subcapsular and medial sector cataract formation (two pati ents), retinopathy (two patients), mild eyelid retraction (one patient ), and dry eye with secondary conjunctivitis (one patient). Conclusion : Carefully planned radiotherapy with lens shielding is an effective a nd safe treatment in the management of orbital lymphoma. We recommend megavoltage radiation doses of 30-35 Gy in 180-200 cGy fractions for l ow grade lesions, and 36-40 Gy for intermediate and high grade lesions .