Cluster 1399: cns radiographic completion metastases directed hemorrhage interim provided anticonvulsants optic Cluster 1600: anticancer therapies offered lapatinib nf imatinib erlotinib basis bevacizumab antibody Cluster 2003: optic nerve chiasm glioma pathway apparatus nf tumor patients medulla Cluster 2160: supratentorial tumor location remote brain compartment elective craniotomy glioma evidence