 - Eligible diseasesstages AJCC Stage I, II, III or IV lung cancer of any histology to be treated using radiotherapy will be eligible for this study. Note that we will carefully consider the inclusion of cases with turbulent flow or greater flow velocities Cabahug et al., 1996; Crawford et al., 1990 and COPD cases Magnant et al., 2006 due to the impaction of aerosol particles in central airways. 