Salvage therapy for primary central nervous system lymphoma with 90Y-Ibritumomab and Temozolomide

Temozolomide is effective and well tolerated in patients with primary vitreoretinal lymphoma

Baron et al report excellent responses to temozolomide in 21 patients (19 relapsed/refractory) with primary vitreoretinal lymphoma. Treatment is well tolerated, even in elderly patients.

Management of primary central nervous system lymphoma

A rare tumor, primary central nervous system lymphoma can affect immunocompetent and immunocompromised patients. While sensitive to radiotherapy or chemotherapy crossing the blood-brain barrier, it often recurs. Modern treatment consists of high-dose methotrexate-based induction chemotherapy, often followed by consolidation with either radiotherapy or further chemotherapy. Neurotoxicity is however a concern with radiotherapy, especially for patients older than 60 years. The benefit of the addition of rituximab to chemotherapy is unclear. Targeted therapies and immunotherapy have been effective in some patients and are tested on a larger scale. Survival has improved in the last decade, but remains poor in older patients.

Temozolomide and unusual indications: review of literature

Temozolomide (TMZ) was first known to be useful as a radiosensitiser in both primary brain tumours like glioblastoma multiforme and oligodendroglioma. Later, TMZ proved its efficacy in the treatment of melanoma. Multiple publications have demonstrated the benefit of TMZ in terms of efficacy and tolerance (used as mono-therapy or as adjuvant chemotherapy) compared to the "gold standard" treatment of this kind of tumours. Furthermore, several recent clinical trials have shown the particular importance of TMZ in other types of cancer. This publication deals with the use of TMZ in cancers which are not formal indications for TMZ (excluding glioblastoma multiforme, oligodendroglioma and melanoma). It also includes a necessary review of recent literature about the role of TMZ in the treatment of brain metastases, lymphomas, refractory leukaemia, neuroendocrine tumours, pituitary tumours, Ewing's sarcoma, primitive neuroectodermal tumours, lung cancer and other tumours.

First report on a prospective trial with yttrium-90-labeled ibritumomab tiuxetan (Zevalin) in primary CNS lymphoma

Most patients with primary CNS lymphoma (PCNSL) relapse after primary therapy. Standard salvage treatment has not yet been established in PCNSL. Anti-CD20 immunotherapy has expanded treatment options in systemic B-cell lymphoma; however, its use is limited by reconstitution of the blood-brain barrier after tumor shrinkage. The aim of this phase II trial was to evaluate the therapeutic efficacy, toxicity, and biodistribution of yttrium-90 ((90)Y) ibritumomab tiuxetan in PCNSL. Ten patients with relapsed PCNSL were included in a phase II trial and treated with the (90)Y-labeled anti-CD20 antibody ibritumomab tiuxetan. Nine patients actually received the planned radioimmunotherapy. In six patients, biodistribution of the antibody was measured by indium-111 ((111)In) ibritumomab tiuxetan whole-body scans and single-photon-emission CT (SPECT) of the brain. All patients were evaluated for toxicity and response at least 4 weeks after therapy. Four patients responded: one patient had a complete response lasting 30+ months, and three patients had short-lived responses of </=4 weeks. Five patients progressed, and one patient did not receive treatment due to an infection prior to (90)Y-antibody administration. Target accumulation of the antibody was demonstrated in four of the six patients examined by SPECT imaging with (111)In ibritumomab tiuxetan. All patients experienced grade 3/4 hematotoxicity but no acute neurotoxicity. Penetration of a therapeutic antibody into PCNSL and significant clinical activity was shown. Because of limited response duration and considerable hematotoxicity, future investigations should focus on a multimodal approach with additional chemotherapy and preferably autologous stem cell support.