Radiotherapy in the Management of Orbital Lymphoma: A Single Institution's Experience Over 4 Decades.

Abstract

To report our institution's treatment techniques, disease outcomes, and complication rates after radiotherapy for the management of lymphoma involving the orbits. We retrospectively reviewed the medical records of 44 patients curatively treated with radiotherapy for stage IAE (75%) or stage IIAE (25%) orbital lymphoma between 1969 and 2013. Median follow-up was 4.9 years. Thirty-eight patients (86%) had low-grade lymphoma and 6 (14%) had high-grade lymphoma. Radiation was delivered with either a wedge-pair (61%), single-anterior (34%), or anterior with bilateral wedges (5%) technique. The median radiation dose was 25.5 Gy (range, 15 to 47.5 Gy). Lens shielding was performed when possible. Cause-specific survival and freedom from distant relapse were calculated using the Kaplan-Meier method. The 5-year local control rate was 98%. Control of disease in the orbit was achieved in all but 1 patient who developed an out-of-field recurrence after irradiation of a lacrimal tumor. The 5-year regional control rate was 91% (3 patients failed in the contralateral orbit and 1 patient failed in the ipsilateral parotid). Freedom from disease, cause-specific survival, and overall survival rates at 5 and 10 years were 70% and 55%, 89% and 89%, and 76% and 61%, respectively. Acute toxicity was minimal. Ten patients (23%) reported worsened vision following radiotherapy, and cataracts developed in 17 patients. Cataracts developed in 13 of 28 patients treated without lens shielding (46%) and 4 of 16 patients (25%) treated with lens shielding. Radiotherapy is a safe and effective local treatment in the management of orbital lymphoma.