First Use of Temozolomide in Primary Intra-Ocular Lymphoma (PIOL): a Very Well Tolerated and Potentially Effective Treatment.

PIOL is a rare subset of primary central nervous system lymphoma (PCNL), representing 5 to 20% of PCNL. It is usually an aggressive diffuse large B-cell lymphoma. There is no consensus on treatment procedures, classical attitudes are systemic chemotherapy (SC), radiotherapy or intraocular injection of methotrexate (IM). Relapse rate is high, with more than 10% of cases relapsing in brain. New treatments are necessary, especially with a good tolerance profile. Temozolomide (Te) has some efficiency on PCNL and seems to be a potential candidate.

we retrospectively analyzed PIOL treated by Te in our unit. Inclusion criteria were a diagnosis established on cytological and molecular analysis after vitrectomy or anterior chamber puncture, and the absence of brain or meningeal localization. Interleukin 10 (IL10) and 6 (IL6) dosages were made by enzyme-linked immunosorbent assay on ocular material. IL10/6 ratio >1 is a specific and sensitive test for PIOL diagnosis and IL10 kinetic a good marker of response in parallel with clinical examination. Treatment consisted in Te at 150mg/m² orally 5 days per month, in monotherapy, without corticosteroid use.

four patients were analyzed, 3 males and one female. All received systemic chemotherapy with at least high dose methotrexate in first line, two with addition of high dose cytarabin. First patient, aged 84 at diagnosis, relapsed 15 month after CR and received Te for three months until here death, probably by CNS lymphoma. Second patient, aged 65, progressed under SC and subsequently received IM without any success; Te was used in third line but no effect was seen. Third patient, aged 48, had a partial response after first line treatment and received SC with high dose cytarabin and stem cell transplantation; after CR he relapsed 33 months later and then received Te, partial response was clinically confirmed at 3 months and is stable at 6 months. Last patient, age 71, had a localized PIOL 3 years after the treatment of a follicular lymphoma; PIOL relapsed 6 month after the first line and Te began; clinical response was spectacular, with a vision normalization in less than one month, a clinical CR confirmed at two months, IL10 dosages were at more than 1500 pg/ml in both eyes before Te, at 22 pg/ml (left eye) after one month and 202 pg/ml (right eye) after two months, response is stable at 5 months. No toxicity appeared during treatment except for hematological grade I or II.

Temodal is a safe and effective treatment of PIOL after classical chemotherapy. Longer follow-up and larger studies are necessary to confirm these data

No relevant conflicts of interest to declare.