Indolent stage IE non-Hodgkin's lymphoma of the orbit: results after primary radiotherapy.

Objective: Primary non-Hodgkin's lymphoma (NHL) of the orbit is uncommon, representing approximately 8% of extranodal NHLs. Twenty-two patients with indolent stage IE NHL were reviewed retrospectively to analyze the outcome and late effects of primary local radiotherapy.

Methods: The median age at first diagnosis was 63.5 years (range 24-82 years). Extranodal mucosa-associated lymphoid tissue lymphoma (n = 15) was the most common histological subtype of NHL, followed by follicular (n = 6) and lymphoplasmacytic lymphoma (n = 1). Radiotherapy was performed using a linear accelerator. The median radiation dose was 40 Gy (range 30-46 Gy). None of the patients received chemotherapy before irradiation. The follow-up period was 62 months (range 8-136 months).

Results: A complete response was achieved in all patients. The 5-year local control rate was 100%. Distant relapse occurred in 2 patients, resulting in a 5-year distant relapse-free survival rate of 88%. The 5-year overall survival rate was 89%; there were no lymphoma-related deaths. No serious acute complications (grade 3/4) were observed. Grade 1/2 late effects were documented in 44% of patients. Grade 3 complications (cataract: 2, dryness: 2) were observed in 4 patients (18%).

Conclusions: Indolent early stage orbital NHL can be controlled with local radiotherapy. Morbidity is low. Regular follow-up examinations are necessary to detect rare cases of distant relapse.