Cluster 766: untreated nervous central metastases cns active symptomatic brain known progressing Cluster 951: cns metastases nervous central symptomatic untreated neurologically patients known primary Cluster 1176: cns metastases symptomatic untreated patients active known uncontrolled excluded brain Cluster 1234: excluded subjects metastases brain clinical trial cancers treated cns primary Cluster 1893: brain symptomatic metastases inclusive uncontrolled requiring corticosteroids limited concurrent radiation Cluster 1975: metastases brain known participants excluded patients corticosteroids treated imaging clinical Cluster 2125: brain metastases excluded trial clinical known patients participants untreated symptomatic