Low-dose 'boom-boom' radiotherapy for ocular lymphoma arising from IgG4-related ophthalmic disease: Case report and literature review.

Ocular adnexal extranodal marginal zone lymphoma (OA-EMZL) and immunoglobulin G4-related ophthalmic disease (IgG4-ROD) may exist on a continuum. Presence of immunoglobulin light-chain restriction and clonal gene rearrangement suggests presence of lymphoma; whereas bilateral, infraorbital nerve and systemic involvement accompanied by elevated serum IgG4 levels may indicate synchronous IgG4-ROD. Although steroids have been the mainstay for the treatment of IgG4-ROD, radiotherapy (RT) has been used occasionally. The reported RT doses range between 24 and 30 Gy, which can result in acute and late toxicities. A low-dose regimen of four Gy has not been previously described. We describe a patient with bilateral OA-EMZL arising from IgG4-ROD successfully treated with low dose 'boom-boom' radiotherapy. In addition, we review the literature for the association between these two conditions and the role of RT in their management.