A retrospective evaluation of risk factors for an inadequate surgical margin in preoperative lipiodol marking for small-sized pulmonary lesions.

Background: Accurate localization and complete resection of pulmonary nodules are crucial in management of lung cancer. Computed tomography (CT)-guided lipiodol marking aids in preoperative localization, but factors affecting marking of surgical margins remain underexplored. This study aimed to identify risk factors for inadequate surgical margin following wedge resection after preoperative CT-guided lipiodol marking for small-sized pulmonary lesions. Methods: A retrospective study was performed in 134 patients with 140 nodules marked with lipiodol for wedge resection. Factors including required resection depth, radiological characteristics, and tumor diameter were assessed for their impact on resection success, which was defined as a resection margin/tumor size (M/T) ratio ≥1. Optimal cut-off values for successful resection were identified as an aid to preoperative decision-making. Results: The resection success rate was 71.4%. The required resection depth significantly influenced resection outcomes (P<0.001). Radiological findings (P=0.04) and tumor diameter (P<0.001) also correlated with resection success. A deeper required resection depth and complex nodular characteristics were associated with resection failure. The optimal cutoff for the required resection depth was 32.4 mm [area under the curve (AUC): 0.68; sensitivity: 57.5%; specificity: 73.0%] for predicting resection success (M/T ratio ≥1). Conclusions: CT-guided lipiodol marking is effective, but careful consideration of factors influencing surgical margins is crucial for successful resection. Further studies are warranted for refining surgical strategies.