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

Abstract

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 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.

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.

Figure 1

Disease-Free Survival (DFS). The delay of DFS was calculated from the date of the end of radiotherapy until the date of revealing of a progress or until the date of death, or until the date of last news (47 patients, 12 events, 35 censored).

Figure 2

Overall survival (OS). The delay of OS was calculated from the date of the end of radiotherapy until the patient's death or until the date of last news (47 patients, 4 events, 43 censored).