Ultrasound examination is more sensitive than CT scanning in assessing chest wall involvement in lung cancer patients, according to findings published in the April issue of Chest.

"The recognition of chest wall involvement preoperatively is important for staging and surgical planning," Dr. William Lunn, of Baylor College of Medicine, Houston, Texas, and colleagues write. "Multiple modalities are available to assess the chest wall involvement preoperatively, including CT scanning, MRI, and ultrasound examination."

The researchers examined the accuracy of transthoracic ultrasound for this purpose compared to that of CT scanning and surgery in 90 lung cancer patients with clinical suspicion of chest wall involvement.

Chest wall invasion by tumor was found in 26 patients at surgery. Ultrasound identified 26 patients as having tumor invasion; there were 23 true-positive results, three false-positive results, and three false-negative results. CT scanning yielded 11 true-positive results, no false-positive results and 15 false-negative results.

Ultrasound had a sensitivity of 89 per cent and a specificity of 95 per cent, while CT scanning had a sensitivity of 42 per cent and a specificity of 100 per cent. The overall diagnostic accuracy of ultrasound was 91 per cent, compared with 83 per cent with CT scanning.

Ultrasound complements CT scan data, Dr. Lunn's team adds. "The extension of tumor beyond the parietal pleura into the chest wall can be confidently determined if the mass is seen to breech the pleura, with loss of the movement of the mass with respiration," they note. "We hope that more clinicians will start using thoracic ultrasound in the near future."


Chest 2008;133:881-886.