Clinicopathological factors associated with sentinel lymph node detection in non-small-cell lung cancer.

BACKGROUND: Mapping of the pulmonary lymphatic system by near-infrared (NIR) fluorescence imaging might not always identify the first lymph node relay. The aim of this study was to determine the clinicopathologic factors allowing the identification of sentinel lymph nodes (SLNs) by NIR fluorescence imaging in thoracic surgery for non-small-cell lung cancer (NSCLC). METHODS: We conducted a retrospective review of 92 patients treated for suspected or confirmed cN0 lung cancer with curative intent who underwent an intraoperative injection of indocyanine green (ICG) either by direct peritumoral injection or by endobronchial injection using electromagnetic navigational bronchoscopy (ENB). After exclusion of patients for technical failure, benign disease and metastasis, we analyzed the clinicopathologic findings of 65 patients treated for localized-stage NSCLC, comparing the group with identification of SLNs (SLN-positive group) with the group without identification of SLNs (SLN-negative group). RESULTS: Forty-eight patients (73.8%) were SLN-positive. Patients with SLN positivity were more frequently female (50%) than the SLN-negative patients were (11.8%) (p = 0.006). The mean value of diffusing capacity for carbon monoxide (DLCO) was lower among the patients in the SLN-negative group (64.7% ± 16.7%) than the SLN-positive group (77.6% ± 17.2%, p < 0.01). The ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FCV) was higher in the SLN-positive group (69.0% vs. 60.8%, p = 0.02). Patients who were SLN-negative were characterized by a severe degree of emphysema (p = 0.003). There was no significant difference in pathologic characteristics. On univariate analyses, age, female sex, DLCO, FEV1/FVC, degree of emphysema, and tumor size were significantly associated with SLN detection. On multivariate analysis, DLCO > 75% (HR = 4.92, 95% CI: 1.27-24.7; p = 0.03) and female sex (HR = 5.55, 95% CI: 1.25-39.33; p = 0.04) were independently associated with SLN detection. CONCLUSIONS: At a time of resurgence in the use of the sentinel lymph node mapping technique in the field of thoracic surgery, this study enabled us to identify, using multivariate analysis, two predictive factors for success: DLCO > 75% and female sex. Larger datasets are needed to confirm our results.

Sentinel Lymph Node in Non-Small Cell Lung Cancer: Assessment of Feasibility and Safety by Near-Infrared Fluorescence Imaging and Clinical Consequences.

Occult micrometastases can be missed by routine pathological analysis. Mapping of the pulmonary lymphatic system by near-infrared (NIR) fluorescence imaging can identify the first lymph node relay. This sentinel lymph node (SLN) can be analyzed by immunohistochemistry (IHC), which may increase micrometastasis detection and improve staging. This study analyzed the feasibility and safety of identifying SLNs in thoracic surgery by NIR fluorescence imaging in non-small cell lung cancer (NSCLC). This was a prospective, observational, single-center study. Eighty adult patients with suspected localized stage NSCLC (IA1 to IIA) were included between December 2020 and May 2022. All patients received an intraoperative injection of indocyanine green (ICG) directly in the peri tumoural area or by electromagnetic navigational bronchoscopy (ENB). The SLN was then assessed using an infrared fluorescence camera. SLN was identified in 60 patients (75%). Among them, 36 SLNs associated with a primary lung tumor were analyzed by IHC. Four of them were invaded by micrometastases (11.1%). In the case of pN0 SLN, the rest of the lymphadenectomy was cancer free. The identification of SLNs in thoracic surgery by NIR fluorescence imaging seems to be a feasible technique for improving pathological staging.

What is the appropriate "first lymph node" in the era of segmentectomy for non-small cell lung cancer?

Introduction: The place of segmentectomy in the management of lung cancer is shifting following the inspiring results of the Japanese JCOG0802 trial. I n this study, authors suggested that performing segmentectomy would require in an optimal way an intraoperative confirmation of pN0 tumor with a frozen section. Our objective was to determine whether the proposed technique, i.e. adjacent lymph node analysis, is consistent with the results of our study on sentinel lymph node (SLN) detection using fluorescence. Methods: This is a retrospective, observational, single center study. Eighty-one patients with suspected localized stage NSCLC (IA to IIA) were included between December 2020 and March 2022. All patients received an intra-operative injection of indocyanine green (ICG) directly in the peritumoral area or by electromagnetic navigational bronchoscopy (ENB). The SLN was then assessed by using an infrared fluorescence camera. Results: In our cohort, SLN was identified in 60/81 patients (74.1%). In 15/60 patients with identified SLN (25%), NIR-guided SLN was concordant with the suggestions of JCOG0802 study. A retrospective SLN pathological analysis was performed in 43 patients/60 cases with identified SLN (71.2%), including 37 cases of malignant disease. Occult micro-metastases were found in 4 patients out of 37 SLN analyzed, leading to a 10.8% upstaging with NIR-guided SLN analysis. Dicussion: At the time of segmentectomies, ICG technique allowed the identification of the SLN in a high percent of cases and in some areas usually out of the recommended stations for lymph node dissection.