Computed tomography-guided dye localization for deeply situated pulmonary nodules in thoracoscopic surgery

Increased lung cancer screening of asymptomatic adults using low-dose computed tomography (CT) with high-resolution imaging modalities has increased the identification of small and deeply situated pulmonary nodules. This study aimed to evaluate the role of preoperative patient blue vital (PBV) dye localization for an undiagnosed nodule deeply situated in the lung parenchyma followed by minimally invasive lung resection.

From July 2013 to December 2016, 27 consecutive patients (16 women, median age: 62 years) with small undiagnosed pulmonary nodules at a depth of more than 30 mm underwent preoperative CT-guided PBV dye localization followed by thoracoscopic diagnostic resection of the nodule at National Taiwan University Hospital. The clinical characteristics were collected retrospectively to evaluate the efficacy and safety of the procedure.

The median size of pulmonary nodule in preoperative CT images was 11 mm with a median depth of 31.6 mm (range, 30.0-48.6 mm). Of the 27 nodules, 8 were pure ground-glass nodules, 3 were pure solid nodules, and 16 were partially solid nodules. The diagnostic yield of CT-guided dye localization following diagnostic wedge resection was 100%. The final pathological diagnoses were: primary adenocarcinoma of the lung (n=20), adenocarcinoma in situ (n=1), and benign nodules (n=6). Only asymptomatic complications were noted after localization, and the median hospital stay was 3 days [interquartile range (IQR), 3-4 days]. All of 21 patients were cancer-free after a median follow-up of 39.0 months (IQR, 29.5-50.0 months).

This study indicated that preoperative, percutaneous CT-guided PBV dye localization for undiagnosed nodules at a depth of more than 30 mm could be a safe and feasible procedure. Furthermore, it was considerably advantageous for preserving the lung parenchyma, especially for benign nodules.