Intraoperative radioguided sentinel lymph node biopsy in non-small cell lung cancer.

Objectives: The aim of this study was to determine the accuracy and the role of the sentinel lymph node (SLN) technique in patients with early non-small cell lung cancer (NSCLC).

Methods: This study was carried out on 29 consecutive patients (M/F = 24:5, mean age 65.9 +/- 7.1 years) with resectable NSCLC (Stage IA-IB). Intraoperative injection with a (99m)Tc-nanocolloid suspension was performed in the first ten patients; the following patients were injected under computed tomography scan guidance. A total dose of 37 MBq (1 ml) was administered in two to four divided aliquots (depending on the size), injected in the periphery of the tumour. Intraoperative radioactivity counting started a mean of 1 h (range 50-70 min) after the injection. The SLN was defined as the node with the highest count rate using a handheld gamma probe counter. Resection with mediastinal node dissection was performed and findings were correlated with histologic and immunohistochemistry (IHC) examination.

Results: Three of the 29 patients did not have NSCLC (two benign lesions, and one metastatic breast tumour) and were excluded. The SLN was identified in 25/26 (96.1%) patients (a total of 31 SLNs); 7/31 (22.5%) of the SLNs were positive for metastatic involvement after histologic and IHC examination. One inaccurately identified SLN was encountered (3.8%).

Conclusions: These preliminary results demonstrate the feasibility of this procedure in identifying the first site of potential nodal metastases of NSCLC. The actual clinical impact of this procedure remains to be elucidated by further investigation in larger groups of patients.