ABSTRACT
Leptomeningeal disease (LMD) (otherwise known as leptomeningeal metastasis, neoplastic meningitis, or leptomeningeal carcinomatosis) describes the spread of tumor cells into the leptomeninges (comprising the arachnoid mater and pia mater) and the cerebrospinal fluid (CSF) of the subarachnoid space. Therapeutic options and their effectiveness for patients with LMD are generally limited. Radiotherapy has long been an established treatment option and is primarily delivered as WBRT, focal spinal radiotherapy, or craniospinal irradiation (CSI) in carefully selected patients to palliate symptoms. Recently, there has been a shift in practice from WBRT to focal stereotactic radiosurgery or hypofractionated stereotactic radiotherapy (SRS/HSRT) for patients with limited parenchymal brain metastases. Accordingly, recent reports have suggested that focal SRS/HSRT may have a role in certain patients with limited LMD. The use of HSRT/SRS for highly selected patients with focal LMD may be a viable treatment option, although it is controversial, given a lack of supportive high-level clinical data.
