Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been substantial interval decrease in the trace right pleural effusion following drainage . A right perihilar airspace opacity corresponding to radiation pneumonitis is unchanged when allowing for differences in technique . Prominent interstitial lung markings in the right lung the may be due to lymphatic congestion or lymphangitic spread of metastasis . The left lung is clear . There is no appreciable pneumothorax . The heart and mediastinum are within normal limits .
    OUTPUT:
    
Substantial interval decrease in trace right pleural effusion following drainage . No pneumothorax . Right lung radiation pneumonitis . Asymmetric right lung interstitial prominence may be due to lymphatic congestion or lymphangitic spread of metastasis .