Leptomeningeal Metastases

Treatment options for leptomeningeal metastases are expanding with greater tolerability and efficacy than in the past. Improved knowledge of molecular subtypes of some cancers can guide in choosing more effective therapeutic options; however, physicians should be mindful that these molecular types can be different in the central nervous system compared to the rest of the body. This is particularly true in breast and lung cancer, in which some patients now can live for many months or even years after diagnosis of leptomeningeal metastases. Options for intrathecal therapies are expanding, but physicians should be mindful that this is a passive delivery system that relies on normal CSF flow, so therapies will not penetrate bulky or parenchymal disease sites, especially in the presence of abnormal CSF flow. When chemotherapeutic options are lacking or unsuccessful, focal radiosurgery which can provide symptomatic relief and proton craniospinal radiation remain effective options. Hopefully more formal studies will be conducted in the future to verify which treatments are indeed most effective for particular types of cancer.