Clinical research progress of intrathecal therapy in the treatment of leptomeningeal metastasis

Leptomeningeal metastasis (LM) is a serious late complication in patients with solid tumors, which is common in patients with lung cancer, breast cancer and melanoma. In recent years, due to the progress of diagnosis, the diagnosis rate of LM has gradually increased. The main goal of the therapy is to maintain neurological function, improve the quality of life and the overall survival rate, and prolong the progression-free survival time of patients. Intrathecal therapy is one of the main treatments for LM, which can deliver drugs directly to the subarachnoid space. The traditional intrathecal drugs are methotrexate, cytarabine and thiotepa. With the development of new research, a variety of chemotherapeutic drugs, targeted drugs and immune checkpoint inhibitors have also been used in intrathecal therapy. In addition, different ways of intrathecal administration also bring new hope to patients. This article reviewed the clinical research progress of intrathecal therapy in the treatment of LM.