P2. VATS sentinel node biopsy reduces the need for systematic mediastinal lymphadenectomy in early stage NSCLC

Objective: Systematic mediastinal lymphadenectomy is still essential for an adequate postoperative staging of non-small cell lung cancer (NSCLC). We tried to investigate the controversial role of sentinel node biopsy (SNB) in early stage NSCLC surgery using videothoracoscopic approach (VATS).

Methods: A total of 52 patients with clinical T1N0MO NSCLC underwent SN navigation VATS lobectomy using Tc-99 labeled tin colloid followed by systematic mediastinal lymphadenectomy (SML) in 2 years time period (2010-2012). Mapping of the mediastinal lymph nodes by their number and station followed by hystopathological evaluation was performed. Patients data were statistically analyzed.

Results: Intraoperative SN was identified in 45 (87%) of these patients with 92% of accuracy. We found lobe specific skip nodal metastases in 5 (10%) patients resulting in upstaging. The incidence of ML metastases seemed to be more often in adenocarcinoma patients (P<0.05), but skip nodal metastases showed higher rate in squamous cell carcinoma patients. Intraoperative frozen section was not confirmed accurate for detecting micrometastases in two (4%) patients. Operative time was prolonged for 10 [8-25] minutes showing no difference in complication rate.

Conclusions: Minimally invasive VATS procedure showed absolute safety and high accuracy. Our results indicated that SN identification could reduce mediastinal lymph node dissection in early stage NSCLC. Further clinical studies should be carried out in order to prove that minimally invasive surgical procedures could be curative for T1N0MO NSCLC.

Keywords: Non-small cell lung cancer (NSCLC); mediastinal lymphadenectomy; sentinel node