Intraoperative computed tomography after tumor marking with metal clips for non-palpable lung tumors.

Background: Locating small, non-palpable lung tumors during video-assisted thoracoscopic surgery (VATS) is difficult. In this paper, we report a simple method to identify such tumors during VATS, using intraoperative computed tomography (IO-CT).

Methods: From 2015 to 2017, we performed IO-CT scans for patients who preoperatively seemed to have non-palpable lung tumors. We initially tried to locate these tumors by finger palpation through the thoracoscopic ports. IO-CT scans were performed after marking tumors with metal clips. However, difficult-to-palpate tumors were marked by initially locating the intercostal muscle from preoperative CT. Metal clips were applied just under the intercostal muscle, and IO-CT scans were performed. After locating the tumor in relationship to the marking clips, patients would undergo wedge resections during VATS, using surgical staplers.

Results: We used this procedure on 21 tumors in 18 patients, including 9 non-palpable tumors and 12 palpable tumors (mean tumor size: 7.3 mm; mean distance from pleura: 6.8 mm). All tumors were identified intraoperatively, and all patients successfully underwent wedge resections during VATS, with no intra-postoperative complications.

Conclusion: IO-CT scans after tumor marking with metal clips during VATS can accurately locate non-palpable small sized lung tumors. IO-CT scans should be indicated for tumors that are preoperatively considered to be non-palpable.