Radiotherapy is successful treatment for orbital lymphoma

To describe the clinical presentation, treatment technique, outcome and complications in a large single institutional experience using radiotherapy for treatment of orbital lymphoma.

Twenty-five patients with lymphoma of the orbit or ocular adnexa were treated with radiotherapy at Stanford University Medical Center during the fourteen year period, 1977-1991. Patients were staged using the Ann Arbor criteria with chest x-ray, computerized tomography of abdomen and orbits, lymphangiogram, and bone marrow biopsy. Patients with disease localized to the orbits as well as those with disseminated disease and symptomatic orbital lesions were treated. Thirty-one involved 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 patients with diffuse large cell lymphoma also received chemotherapy as part of their initial treatment. Follow-up ranged from 10 months to 13 years, with a mean follow-up time of 4 years.

Twenty patients had 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; follicular mixed, 3; diffuse small cleaved, 3; diffuse large cell, 2; follicular small cleaved, 1; follicular and diffuse small cleaved, 1; undifferentiated, 1. Two local relapses occurred; the actuarial 5-year freedom from local relapse is 89%. Actuarial 5-year freedom from distant relapse, freedom from any relapse and overall survival are 77%, 70%, and 93%, respectively. Acute complications of treatment were mild. Late complications included transient cystoid macular edema (one patient), asymptomatic subcapsular and medial sector cataract formation (two patients), retinopathy (two patients), mild eyelid retraction (one patient), and dry eye with secondary conjunctivitis (one patient).

Carefully planned radiotherapy with lens shielding is an effective and safe treatment in the management of orbital lymphoma. We recommend megavoltage radiation doses of 30-35 Gy in 180-200 cGy fractions for low grade lesions, and 36-40 Gy for intermediate and high grade lesions.