Rituximab alone in the management of primary orbital lymphoma of the conjunctiva


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David Woolf1, Hariharan Kuhan1, Asad Qureshi1, Swee-Ling Wong1, Victoria Cohen1, Nick Plowman1
1St Bartholomew's Hospital, London, UK

Background

Orbital lymphoma is a rare condition, normally of low grade histology, which is often confined to the conjunctiva. After full histological and radiological assessment the standard treatment for low grade conjunctival disease confined to the orbit (IE) is radiotherapy with 30 Gray in 15 fractions over 3 weeks. The standard technique employed in our centre is the use of an anterior 300KV portal with a contact lens placed between the lids bearing a centrally mounted lead cylinder to cause a shadow over the lens and thereby reduce the risk of cataract formation. Although this technique has excellent control rates there is associated toxicity including conjunctivitis, telangiectasia formation and minor retinopathy as well as a theoretical risk of late malignancy.

Rituximab, anti CD20 monoclonal antibody, has been gaining support for use as a monotherapy for lymphoma with durable responses.

Method

Four patients with primary conjunctival lymphoma were treated with a standard course of 6 cycles of 375mg /m2 of rituximab given every 3 weeks after giving informed consent. They all had biopsy proven MALT lymphoma and had been imaged with an MRI scan of the orbits as well as a negative whole body staging CT scan.

Results

Mean age was 41 yrs old with an equal gender split (2 males, 2 females). Median follow-up was 38 months (range 30-46). All patients had complete initial response to treatment with minimal toxicity. However 2 patients (50%) relapsed at 15 and 24 months. These 2 patients received conventional radiotherapy with complete response.

Conclusion

Conjunctival lymphoma can be treated with rituximab monotherapy with a reasonable success rate and minimal toxicity. Cure rates are not compromised as second line radiotherapy can be used with excellent results. A randomised controlled trial is being planned.