Accuracy of transthoracic ultrasound for the prediction of chest wall infiltration by lung cancer and of lung infiltration by chest wall tumours.

Background: We wanted to determine the accuracy of transthoracic ultrasound in the prediction of chest wall infiltration by lung cancer or lung infiltration by chest wall tumours.

Methods: Patients having preoperative CT-scan suspect for lung/chest wall infiltration were prospectively enrolled. Inclusion criteria for lung cancer were: obliteration of extrapleural fat, obtuse angle between tumour and chest wall, associated pleural thickening. The criteria for chest wall tumours were: rib destruction and intercostal muscles infiltration with extrapleural fat obliteration and intrathoracic extension. Lung cancer patients with evident chest wall infiltration were excluded. Transthoracic ultrasound was preoperatively performed. Predictions were checked during surgical intervention.

Results: Twenty-three patients were preoperatively examined. Sensitivity, specificity, positive and negative predictive values of transthoracic ultrasound were 88.89%, 100%, 100% and 93.3%, respectively. Youden index was used to determine the best cut-off for tumour size in predicting lung/chest wall infiltration: 4.5cm. At univariate logistic regression, tumour size (<4.5 vs ≥ 4.5cm) (p=0.0072) was significantly associated with infiltration.

Conclusions: Transthoracic ultrasound is a useful instrument for predicting neoplastic lung or chest wall infiltration in cases of suspect CT-scans and could be used as part of the preoperative workup to assess tumour staging and to plan the best surgical approach.