Locating Lung Tumors

Lung cancer is the second most common type of adult cancer in the U.S. and the leading cause of cancer death. Traditional X-rays can detect suspicious lesions in the lungs, but can't tell if the areas are cancer. In addition, X-rays can only detect lesions at least three centimeters big. By the time a lung cancer has reached that size, the cure rate, even without any lymph node involvement, is only about 60 to 70 percent. CT scans are more sensitive, but are also unable to differentiate between cancers and benign lesions.

The only way to definitively diagnose lung cancer is with a biopsy of the suspicious lesion. Traditionally, this is done through a large incision into the chest. The surgeon must spread the ribs to access the lung. Then a portion of lung tissue is removed. In some cases, doctors may remove the entire lung.

Some surgeons attempt to remove lung lesions through minimally invasive surgery, called video-assisted thoracoscopic surgery, or VATS. First, the affected lung is collapsed. Then, a small incision is made in the chest between two ribs. Next, a narrow tube with a video camera is placed through the incision to enable the surgeon to "see" inside the chest.

Tiny surgical instruments are placed through other small incisions to access and remove lung tissue. With VATS, patients avoid the large incision and spreading of the ribs. In addition, a small amount of lung tissue can often be removed. VATS isn't possible for all patients. Doctors need to be able to see the lesion to access the site. Researchers report 54 percent of patients having VATS require a traditional procedure. because the surgeon is unable to visualize or palpate the lesion.

 Researchers at the University of Virginia Health System are using a technique to help them identify and mark the location of a lung lesion so that it can be found during surgery. On the morning of surgery, the patient is taken for a lung CT scan. When the location is confirmed by the scan, the radiologist injects a radioactive substance into, or as close to the site as possible. When the patient is taken to VATS surgery, the lung is collapsed. Then, doctors use a "medical Geiger-counter" to guide them to the exact location of the lesion.

Tiny surgical instruments are used to grasp the affected area of lung tissue and pinch the edges together. Two rows of surgical staples are placed across the section of tissue to seal off the main sections of the lung from the area with the lesion. Then, the tissue containing the lesion is cut away. Surgeons immediately send the lung tissue to a pathology lab for analysis.

Thoracic Surgeon, Thomas Daniel, M.D., says the use of the tracer enables doctors to find 85 to 95 percent of lung lesions through VATS. In 50 percent of cases, the lesions turned out to be benign. Another 33 percent of patients had lung cancers. All but one patient had very early stage cancer with no lymph node involvement. Daniel says studies suggest treatment of lung cancer at this early stage is associated with a 94 percent survival rate at five years. Daniel says the localization technology for lung lesions takes a good deal of teamwork between radiologists, surgeons and pathologists. However, the equipment and personnel to perform the procedure is available at many large hospitals.