Comparison of Preoperative CT Scan Guided and Intraoperative Hybrid DynaCT Scan-Guided Small Lung Tumor Localization: A Randomized Study

Lung Cancer continues to have high morbidity and mortality, and it is estimated that in 2014 in Taiwan there were approximately 11692 new cases and 9167 deaths from lung cancer, which was the first leading cause of cancer deaths. Because 70% of lung cancer patients in Taiwan were diagnosed at late stage, only palliative treatment could be given and prognosis was poor.

Owing so, screening and early detection of early stage lung cancer is of paramount importance. In 2012, the National Lung Screening Trial demonstrated that screening for lung cancer with chest computed tomography (CT) results in a 20% reduction in mortality. Low dose CT(LDCT) has been acknowledged as the most powerful tool for early lung cancer detection. With the increasing use of CT, it is expected that many patients with small lesions (< 2 cm), enlarging lesions, and partially solid lesions that are suspicious for cancer will be discovered and will require surgical resection.

It is well known that video-assisted thoracoscopic surgery(VATS) is preferred to open surgery for lung tumor resection because of the use of smaller incisions and optimized postoperative recovery, including a shorter length of hospitalization. Studies have shown decreased operative and post-operative morbidity with decreased operative times. While this procedure speeds up recovery and potentially reduces complications, the loss of natural vision and tactile sensing makes it difficult for the surgeon to locate the nodules, especially in cases of non-superficial, ground-glass opaque, and small lesions. The yield rate for nodules < 1 cm can be below 40% as studies show. And a more significant resection (more healthy tissue is resected than actually necessary in order to avoid missing the lesion.) or conversion to thoracotomy is occasionally needed to ensure complete resection. In order to improve nodule localization, a variety of methods have been proposed and described to mark lung nodules for easier identification of small nodules and help guide resection during VATS. These ranged from percutaneous image guided injection of a dye (methylene blue) or radio-opaque material such as barium sulphate, to percutaneously placed hookwires and micro-coils in the radiology suite prior to surgery. All these preoperative CT scan guided localization procedures were carried out "outside" operation room and under local anesthesia.

However, there remain certain concerns. First, there are the difficult logistics in minimizing the time between the hookwire procedure and the subsequent surgery. Second, there is concern for patient safety, in particular pneumothorax, during transfer to and from the ward to the radiology department 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 hookwire dislodgement.

Theoretically, the aforementioned disadvantage could be solved by performing the localization procedure and the lung surgery in the same hybrid operating room environment(i.e. Hybrid OR). A hybrid operating room is a surgical theatre that is equipped with advanced medical imaging devices such as fixed C-Arms, CT scanners or MRI scanners. These imaging devices enable minimally-invasive surgery, which is less traumatic for the patient.