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

Luigi De Cicco, Laura Cella, Raffaele Liuzzi, Raffaele Solla, Antonio Farella, Giorgio Punzo, Fausto Tranfa, Diego Strianese, Manuel Conson, Giulio Bonavolontà, Marco Salvatore, Roberto Pacelli

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. 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 gamma 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. 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. Radiotherapy is an effective and at the same time well tolerated treatment for primary orbital lymphoma.