A Study to Test Lung Function After Radiation Therapy (PFS)

Inclusion Criteria:

• Histological diagnosis of small cell or non-small cell lung cancer or metastatic tumor to the lung being scheduled for localized radiation therapy (including radiosurgery)
• No prior or future planned surgery for the treatment of the lung cancer.
• Age ≥ 18 years
• Karnofsky 60%
• Not pregnant.
• Ability to understand and the willingness to sign a written informed consent document
• Ability and willingness to participate in breathing training and compliance wiht breathing apparatus so that radiation doses are optimally linked to 4D-CT images
• Ability to tolerate CT contrast

Exclusion Criteria:

• No prior thoracic radiotherapy will be permitted
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Pregnant women
• Severe COPD that requires chronic prednisone or multiple inhalers
• Underlying collagen vascular disease or intrinsic lung disease that could complicate expected sequelae of radiation (idiopathic pulmonary fibrosis, Wegener's granulomatosis)
• Oxygen dependence at baseline
• Recent lung surgery or abdominal surgery (within 3 weeks) that would compromise respiratory pattern.