<qa>  What is the name of the brain scan performed during screening?9. Subjects with brain or subdural metastases are not eligible, unless they have completed local therapy and have discontinued the use of corticosteroids for this indication at least 4 weeks before starting study treatment. Any symptoms attributed to brain metastases must be stable for at least 4 weeks before starting study treatment; radiographic stability should be determined by comparing contrast-enhanced computed tomography CT or magnetic resonance imaging MRI brain scan performed during screening to a prior scan performed at least 4 weeks earlier 