[1] Natl Masan TB Hosp, Dept Thorac Surg, Clin Res Ctr, Chang Won 631710, South Korea
[2] Seobuk Hosp, Dept Thorac Med, Seoul, South Korea
[3] Natl Mokpo TB Hosp, Dept Thorac Surg, Mokpo, South Korea
[4] Pusan Natl Univ, Yangsan Hosp, Dept Internal Med, Yangsan, South Korea
[5] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Internal Med, Seoul, South Korea