Investigation of sentinel lymph nodes using SPECT/CT and perioperative gamma assay combined with immunohistochemistry in non-small cell lung cancer patients undergoing lung resection

Abstract

PurposeAccurate mediastinal staging is crucial for treatment planning and prognostication in patients with non-small cell lung cancer (NSCLC). Sentinel lymph node (SLN) detection using single-photon emission computed tomography/computed tomography (SPECT/CT) is a promising technique for improving the precision of mediastinal staging. In this study, we aimed to identify the lymph nodes that the tumor will invade based on the lobe in which it exists by determining the lobar drainage pathways. Additionally, we share our experience with the SLN procedure for NSCLC.MethodsThe study included twenty NSCLC patients with N0, N1, or N2 stages, scheduled for surgery and showing no lymph node or distant metastasis on positron emission tomography/computed tomography (PET/CT). Radiopharmaceutical injection around the tumor preoperatively was followed by SPECT/CT visualization. Lymph nodes were counted using a gamma probe post-mediastinal dissection. Evaluation included histopathological analysis of SLNs identified by SPECT/CT and gamma probe, using hematoxylin and eosin and immunohistochemical staining.ResultsAfter postoperative pathological examinations, metastases were found in other mediastinal, hilar, or intrapulmonary lymph nodes without involving the SLN in six patients (30%). Metastasis to the SLN was detected in only two patients (10%). Immunohistochemical staining with cytokeratin revealed SLN metastasis in three patients (15%). The skip metastasis was detected in five patients (25%). Additionally, three patients (15%) experienced pneumothorax post transthoracic radiopharmaceutical injection, which did not require intervention, and one patient (5%) had hemoptysis.ConclusionWe propose that enhancing SLN detection in NSCLC can aid surgeons in selectively sampling lymph nodes that are either invaded or are at risk of invasion without sacrificing the accuracy of mediastinal staging.Clinical trial registrationNot applicable. This manuscript does not report on or involve the use of any clinical trials.