1. Section of Interventional Pulmonology, Division of Pulmonary and Critical Care Medicine; Johns Hopkins University School of Medicine; Baltimore MD USA
2. Division of Pulmonary, Allergy and Critical Care Medicine; University of Pittsburgh School of Medicine; Pittsburgh PA USA
3. Beth Israel Deaconess Medical Center, Division of Pulmonary and Critical Care Medicine; Harvard Medical School; Boston MA USA
4. Department of Radiation Oncology; Johns Hopkins University School of Medicine; Baltimore MD USA