Preoperative evaluation of pleural adhesion in patients with lung tumors using four-dimensional computed tomography performed during natural breathing

The presence of pleural adhesions increases blood loss, occurrence of pulmonary fistulation due to lung injury, and operative time and may complicate thoracoscopic surgery. Recently, it has been reported that four-dimensional computed tomography (4D-CT) synchronized with breathing predicts pleural adhesion. These studies have been performed by asking the patients to maintain a constant respiratory rhythm at the time of scanning. However, many patients face difficulty in doing so, particularly elderly individuals and patients with respiratory dysfunction. We examined the utility of 4D-CT performed while maintaining a natural breathing pattern, which reduces patient burden, in detecting pleural adhesions. A total of 36 patients with a lung tumor near the pleura underwent 4D-CT during free breathing. The migration distance between the lesion and the nearest point on the chest wall on 4D-CT was measured. A sufficient distance indicated the absence of adhesion in that area. The presence of actual adhesions was evaluated and confirmed by intraoperative thoracoscopic findings. There were 7 cases determined to have adhesion by 4D-CT, and 4 of them had actual adhesions confirmed during surgery. The sensitivity and specificity were 80.0% and 90.3%, respectively. The mean migration distance of tumors was 0.8 ± 0.2 cm in the 5 cases with adhesion and 2.6 ± 1.8 cm in the 31 cases without adhesion (P = .01). These results suggest that 4D-CT is a convenient and useful technique for the preoperative assessment of pleural adhesion.