Title:
Preoperative assessment of chest wall invasion in non-small cell lung cancer using surgeon-performed ultrasound.

Abstract:
Chest wall invasion in operable lung cancer upgrades the stage and can affect operative planning. Diagnosing chest wall invasion preoperatively is important in patient consent, in the choice of operative incision placement, and can be helpful in choosing an operative approach (open vs thoracoscopic). The objectives of this study were to determine the diagnostic accuracy of preoperative, surgeon-performed ultrasound (US) in assessing tumoral chest wall invasion (T3) in non-small cell lung cancer (NSCLC) patients and to compare its accuracy vs preoperative computed tomography (CT).
This study was a prospective clinical trial (ClinicalTrials.gov: NCT01206894) that prospectively enrolled patients between September 2010 and January 2013. Eligible patients included those with NSCLC abutting the parietal pleura or invading the chest wall on preoperative CT scan of the chest and who were planned for surgical resection. Criteria for chest wall invasion on US included (1) disruption of the parietal pleura, (2) invasion of the ribs, or (3) impairment of pleural movement with respiration. The US chest wall examination was performed by the thoracic surgical team immediately before the surgical intervention. Sensitivity and specificity for CT scan and US in assessing chest wall invasion were calculated using definitive chest wall invasion on final pathologic analysis as the gold standard for chest wall invasion.
During a 28-month period, 28 patients (15 men and 13 women) patients were prospectively enrolled. Mean age was 62 ± 11 years, and mean body mass index was 25.3 ± 4.5 kg/m(2). The average time for surgeon-performed US assessment looking for chest wall invasion was 5.3 ± 5 minutes. The sensitivity of US in evaluating chest wall invasion was 90.9% and the specificity was 85.7%. CT scan was associated with a sensitivity of 61.5% and a specificity of 84.6%. The positive and negative predictive values of surgeon-performed US for tumoral chest wall invasion were 83.3% and 92.3%, respectively, compared with 80% and 68.8% for CT scan.
Surgeon-performed preoperative chest wall US can reliably diagnose tumoral chest wall invasion in patients with NSCLC. CT scan has poor sensitivity in predicting chest wall invasion preoperatively. Surgeon-performed US can be considered as a complementary adjunct to preoperative imaging in patients with pulmonary lesions abutting the chest wall to improve preoperative diagnosis, staging, and operative planning.