Table 2. Comparison of advantages and disadvantages among the watershed analysis, CT-guided localization and segmentectomy.

Localization methods	Advantages	Disadvantages
Watershed analysis	(I) Localizing the nodules not suitable for computed tomography (CT)-guided percutaneous localization; (II) as an alternative to the failure of CT-guided localization; (III) short operation time; (IV) saving resources of CT room	(I) More lung parenchyma needs to be separated; (II) 3D reconstruction software with the function of watershed analysis is required
CT-guided localization	(I) Simple technique; (II) short duration of operation; (III) high success rate; (IV) low cost	(I) Having the “exclusion zone” of CT-guided localization; (II) limitations and complications can sometimes occur, including dislodgment, dye diffusion, pneumothorax and pulmonary hemorrhage; (III) pain and mental strain; (IV) occupying resources of CT room
Segmentectomy	Resecting the nodules with the depth of more than 3.0 cm, which are not suitable for wedge resection	(I) More sophisticated surgical techniques are needed; (II) longer duration of operation; (III) removal of deeper and more lung parenchyma may cause more complications