Association between ocular findings and preventive therapy with onset of central nervous system involvement in patients with primary vitreoretinal lymphoma

Purpose To investigate if the site of ocular lesions and prophylactic treatment in patients with primary vitreoretinal lymphoma (PVRL) are associated with the time to onset of central nervous system (CNS) involvement. Methods We retrospectively studied 26 patients (seven men, 19 women; mean age, 67.0 +/- 11.1 years) with a diagnosis of PVRL at our hospital between January 2001 and October 2011 and a minimum 2-year follow-up after treatment. We classified the PVRL lesions as: (1) the vitreous opacity type, vitreous opacity of 2+ or higher without retinal lesions, (2) the retina type, vitreous opacity of 1+ or less with retinal lesions only, or (3) the concomitant type, with both. We also evaluated whether prophylactic treatment of systemic chemotherapy such as high-dose methotrexate (HD-MTX) and intrathecal MTX(IT-MTX), or topical ocular treatments such as intravitreal injections of MTX and rituximab, inhibited the onset of CNS involvement in patients with PVRL without cerebral involvement. Results During a mean follow-up of 44.0 +/- 18.7 months, CNS involvement began in 14 patients (53.8 %), i.e., three (60 %) of five patients with retina-type lesions, five (41.7 %) of 12 patients with vitreous opacity-type lesions, and six (66.7%) of nine patients with concomitant-type lesions. There was no significant (P=0.496) association between the site of the ocular lesions and the onset of brain lesions. In addition, CNS involvement occurred in eight of 11 patients receiving CNS prophylactic chemotherapy and six of 15 patients receiving no prophylaxis; the difference between the two did not reach significance (P=0.131). The time to onset of cerebral involvement in the CNS prophylactic chemotherapy group (42.8 +/- 13.8 months) was significantly (P=0.0005) longer than in the group that did not receive prophylaxis (10.2 +/- 2.0 months). Preventive systemic chemotherapy, especially HD-MTX, significantly prolonged the time to the onset of brain lesions compared to IT-MTX and local ocular therapy. Conclusions While prophylactic systemic chemotherapy did not inhibit the onset of CNS involvement in most of patients with PVRL, it significantly prolonged the time to cerebral involvement.