Cluster 311: brain metastases known patients history active subjects presence patient treated Cluster 367: leptomeningeal disease manifestation history presence evidence patients diffuse spread untreated Cluster 511: meningitis carcinomatous subjects known history brain presence leptomeningeal patients metastases Cluster 1088: suspected metastasis leptomeningeal brain known active disease subject needing carcinomatosis Cluster 1284: leptomeningeal metastasis brain disease history known symptomatic presence active patients Cluster 1541: leptomeningeal metastases brain active cns evidence history known disease patients