Purpose: The application of sentinel node navigation surgery in non-small cell lung cancer (NSCLC) is not popular because of the difficulty of sentinel node identification and the low incidence of complications after systemic lymph node dissection. We report the intraoperative assessment of sentinel node metastasis by thoracoscopic ICG fluorescence imaging system and real-time reverse transcription-polymerase chain reaction (RT-PCR).
Methods: Sixty-one patients who underwent surgery between January 2009 and December 2010 were investigated for sentinel node biopsy. ICG fluorescence imaging was applied by an infrared light CCD system, and sentinel nodes were identified and dissected. Intraoperative real-time quantitative RT-PCR to determine the expression of cytokeratin 19 (CK-19) was performed for evaluation of metastasis and finally histologic examination of hematoxylin and eosin-stained, paraffin-embedded sections.
Results: Sixteen (80%) of 20 patients with segmentectomy and 33 (80.5%) of 41 with lobectomy were identified for sentinel lymph nodes. The total identification rate was 80.3% (49 of 61). The false-negative rate was 2.1% (1 of 49). The overall accuracy rate was 78.7% (48 of 61 patients). Disease of four of these patients was upstaged to stage IIA by RT-PCR for CK-19 expression, which was positive for sentinel nodes and micrometastases.
Conclusions: These results demonstrated that thoracoscopic ICG fluorescence imaging-guided surgery and real-time quantitative RT-PCR were useful for sentinel node biopsy and might be a powerful tool for more focused pathologic or molecular evaluation for staging.