Radiation therapy in primary orbital lymphoma: a single institution retrospective analysis

Background: Primary orbital lymphoma is a rare disease that accounts for 10% of all orbital
tumors. Radiotherapy on the orbital cavity is the treatment of choice for this unusual presentation
of localized non-Hodgkin's lymphoma (NHL). The aim of this study is to retrospectively evaluate
the effectiveness and the toxicity of radiation treatment in patients with primary orbital lymphoma.
Methods: Forty-seven consecutive patients having primary orbital lymphoma treated in our
department between May 1983 and September 2006 were investigated in a retrospective study.
Either 60Co ? rays or 6 MV X rays were used to deliver daily fractions of 1.8 or 2.0 Gy, 5 times/
week, with total doses ranging from 34.2 to 50 Gy. Forty-three patients had stage IE, three had
stage II and one stage IV disease. Thirty-eight patients had marginal zone B-cell lymphoma, 5 diffuse
large B cell lymphoma, 3 mantle cell lymphoma and 1 Burkitt lymphoma. Local control (LC), disease
free survival (DFS), overall survival (OS) and late side effects were evaluated in all patients.
Results: With a median follow up of 45 months, LC was obtained in 100% of patients. The
estimated 5- and 7-year DFS rates were 75.8% and 55.3%, and the 5- and 7-year OS rates were
88.7% and 79.9% respectively. Acute toxicity was minimal. Late toxicity such as cataract, keratitis,
retinopathy and xerophthalmia occurred respectively in 12 (25.5%), 5 (10.6%), 1 (2.1%), and 9
(19.1%) patients.
Conclusion: Radiotherapy is an effective and at the same time well tolerated treatment for
primary orbital lymphoma.