In this study, the following topics regarding SN identification in lung cancer patients will be introduced: (1) devices for SN identification using a radioisotope tracer; (2) movement of Tc-99 tin colloid after injection; (3) characteristics of patients in whom SNs could not be identified; (4) results of ex vivo SN identification; (5) reliability of in vivo SN identification; (6) algorithm for reducing mediastinal lymph node dissection; (7) SN identification using SPECT/CT; (8) differences in SN identification between large and small radioisotope particles; (9) size of metastatic and nonmetastatic mediastinal lymph nodes in non-small cell lung cancer; (10) SN navigation segmentectomy for clinical stage IA non-small cell lung cancer; and (11) lymphatic flow at segmental lymph nodes. (Source…