Mobile 3D C-arm CT for Lung Tumor Localization Efficacy Analysis: a Prospective Clinical Trial

Overview

It is well known that video-assisted thoracoscopic surgery (VATS) is preferred to open surgery for lung resection because of the smaller incisions and optimized postoperative recovery, including a shorter length of hospitalization and much decreased local tenderness. Studies have shown less operative and post-operative morbidity with decreased operative times. However, for small nodules (i.e. lesions \<1 cm or those at a distance more than 1.5cm from the lung periphery), adequate identification of the target nodule has been being difficult by VATS with necessity of more significant resection or thoracotomy conversion to ensure complete tumor resection. In order to improve nodule localization, a variety of preoperative localization methods such as CT-guide hook wire or methyl blue dye localization have been proposed. It has been proved to be much easier to mark lung nodules and help guide resection during VATS. However, there are certain concerns. First, it is difficult to minimize the time between the localization procedure and the subsequent surgery in reality. Second, there is concern for patient safety, in particular pneumothorax or hemothorax, during transferred to and from the ward to the radiology suit and in the frequent delays and waiting in reception areas prior to transfer to operating theaters. Finally, interdepartmental transfers and delays can also increase the risk of hook wire dislodgement. Theoretically, the aforementioned disadvantage could be solved by performing the localization procedure and the lung surgery in the same operating room environment. We performed single-step localization and removal of small pulmonary nodules in the hybrid OR equipped with floor-mounted C-arm cone-beam computed tomography (CBCT) in the previous study. However, it costed a lot of money and every localization could only be performed in the hybrid OR. Mobile 3D C-arm CT is another form of CBCT. It depicts soft tissues with high contrast but also offer a more affordable solution with relative low cost. In this case series, we will investigate the use of a mobile 3D C-arm CT for single-step localization and removal of small pulmonary nodules.

Pre-operative CT scans will be used for localization planning. The images will be reviewed by our team to determine optimal placement of wires or indocyanine green. After induction of general anesthesia and insertion of a double-lumen tube, the patient will be placed in either supine, prone or lateral decubitus position. Under end-inspiratory breath-hold, an initial 30 second rotary scan for surgical planning will be obtained. The puncture path will be planned to be as short as possible while avoiding transfissural punctures or being oriented towards major vascular structure. The skin entry site for the planned needle puncture route will then identified under the guidance of the referential metallic marker. An 18-gauze marker needle will be gradually advanced under CT-guidance until it reached the target lesion. A total of 0.3 ml ICG dye(for superficial lesion) or microcoil or hookwire(for deeper lesion) will then be used to localize the tumor.