Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Comparison is made to prior examination of ___ . The heart is normal in size . The mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . The lungs are clear . There are no pleural effusions . Degenerative changes of the thoracic spine are noted .
    OUTPUT:
    
No evidence of metastatic disease .