ENB Robotic ICG Guided Surgery: A Novel Technique for Targeting Small Lung Tumors (ENB-RIGGS)

Robotic ICG Guided Surgery (RIGGS) Using Electromagnetic Navigational Bronchoscopy (ENB): A Novel Technique for Targeting Small Lung Tumors

Lung cancer is the leading cause of cancer deaths worldwide. However, if diagnosed at an early stage (tumor <2 cm), lung cancer is highly curable with a 5-year survival rate greater than 80% after surgical resection. Screening tests have made it easier to identify small lung tumors. However, these tumors are often not visible to the naked eye, and surgeons cannot feel them, making them difficult to precisely locate and remove. For this reason, surgeons have become more reliant on image guided surgery for the removal of these tumors. The standard of care for locating and removing small lung tumors is microcoil-guided video-assisted thoracoscopic surgery (VATS). This is a two-step procedure performed by two separate physicians. First, patient is taken to radiology suite and radiologist inserts a microcoil near the lung tumor Second (usually occurs a few hours later), patient is taken to operating room; a surgeon uses an x-ray arm to find the microcoil within the lung and remove it surgically. A pathologist reviews the resected tissue to make sure that the tumor and the microcoil were both removed. Until this evaluation, the surgeon does not know whether the tumor has been removed or not. While this method is safe, it is time consuming, uses staff resources, and requires bulky equipment to complete. In this study, we plan to develop and test a new method of identifying and removing small lung tumors. This procedure is called Electromagnetic Navigational Bronchoscopy (ENB) Robotic Indocyanine Green Guided Surgery (RIGGS) or ENB-RIGGS for a short name. The purpose of this study is to test the safety and reliability of the ENB-RIGGS surgery in the form of a pilot study. ENB-RIGGS surgery is done in the operating room by a surgeon under general anesthetic. ENB-RIGGS begins by creating a 3-D GPS map of the lung which guides the surgeon directly to the tumor. A fluorescent green dye called indocyanine green is then injected into the tumor, and when viewed by the special robotic camera the tumour will fluoresce with a green hue allowing the surgeon to easily see the tumour. The surgeon then uses the robot to remove the tumor and surrounding tissue. The lung tissue specimen will be evaluated immediately by a pathologist.

In the operating room ENB will be used to locate the targeted lung tumor. Once the tumor is located, the surgeon will advance a bronchoscope to the tumor, a needle will be passed through the bronchoscope, and the tumor will be injected with 100-150 micro liters of ICG solution at 0.125mg/mL concentration. The tumor is expected to fluoresce using the da Vinci Firefly robotic camera, giving off a bright green hue. Wedge resection of the fluorescent part of the lung will then be performed. The excised specimen will be sent for immediate pathologist analysis. If the tumor is found within the specimen, and the specimen margins are free of tumor cells, then the procedure will be completed. If the tumor cannot be targeted or visualized, or if the tumor is not found in the pathological specimen, or if the margins of the specimen contain tumor cells, then a formal anatomical lobectomy or segmental resection of the lung will be performed to ensure that the tumor is completely excised.

Safety determined by the rates of adverse reactions to ICG dye, intra-operative adverse events, and post-operative complications as defined by the Ottawa Thoracic Morbidity and Mortality classification

Reproducibility will be measured by the aggregate score on items 1-4 of the 6-item scale which include: targeting of tumor on ENB (advance a bronchoscope to the targeted tumor); injection of the tumour with ICG; detection of ICG fluorescence with near-infrared light; wedge resection. The reproducibility score for each procedure will be the sum of the first 4 items on the 6-item scale and can range between 0/4 to 4/4. The reproducibility rate will be defined as the percentage of patients who score 4/4 on the reproducibility scale.

The oncological validity score for each procedure will be the sum of the last 2 items on the 6-item scale (ex-vivo localization of tumor; ex-vivo confirmation of tumour-free margins) and can range between 0/2 to 2/2. The oncological validity rate will be defined as the percentage of patients who score 2/2 on the oncological validity scale.

Process Feasibility will be determined by recruitment rate (The proportion of patients enrolled in the study versus the number eligible, up to n=30)

Management Feasibility will be determined by the percentage of cases for which ICG was successfully obtained from pharmacy and prepared for the ENB-RIGGS procedure

Resource Feasibility will be determined by the sum of the dollar costs of the ENB-RIGGS materials and personnel required to perform the procedure, divided by the number of participants.

Inclusion Criteria: Age > 18 years Peripheral lung tumour that is <2 cm in size on a CT scan Fit to undergo thoracic surgery as assessed by the surgeon. Exclusion Criteria: Hypersensitivity or allergy to ICG, sodium iodide or iodine Women who are currently pregnant or are breast feeding; or women of child bearing potential who are not currently taking adequate birth control.

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