August 2008

Lung cancer is among the deadliest of cancers, partially because it is difficult to detect until it has already progressed to a later stage. However, a new bronchoscopy technology offered through PAMF improves the odds of early diagnosis, which in turn increases the chance of a better treatment outcome.

PAMF is able to provide patients with this exciting diagnostic option thanks in part to Ganesh Krishna, M.D., who joined the Mountain View Center last month. He is among the few doctors in the United States who are experts in the inReach electromagnetic navigation bronchoscopy system, and he is currently training his PAMF colleagues on the system.

Electromagnetic bronchoscopy uses technology from the relatively new field of 3-D diagnostic imaging to create a computerized map of the patient’s lungs. The physician uses the map to guide the bronchoscope through the lungs’ narrow delicate airway branches. The system is so precise that growths that were once too deep in the lungs to be biopsied without invasive methods are now reachable by bronchoscope.

"We can direct a typical bronchoscope down only two or three airway branches, but there may be 25 branches before you get to a small nodule in the periphery of the lung," explains Alan Chausow, M.D., a pulmonologist in the Camino region’s Pulmonary Disease & Critical Care Department. "In the past, we would either follow these nodules over time or order a percutaneous biopsy." Dr. Chausow says this involves sticking a long needle through the chest and into the lung, which can sometimes collapse the delicate organ.

Now with electromagnetic bronchoscopy, the risk of an adverse outcome, such as lung collapse, is greatly reduced ─ without sacrificing the physician's ability to get a good tissue sample from a lung lesion for cancer testing.

The procedure begins with a computed tomography (CT) scan of the patient's chest. The inReach software then uses the hundreds of individual CT images collected during the scanning process to generate a 3-D image of the patient's lungs, which allows the physician to target lesions and plan a path to them.

During the procedure, the patient lies on a plate that generates an electromagnetic field so that the computer — and the clinician — can precisely match up the computerized image of the patient's airway branches with the patient's real lungs using metal markers. The physician can then guide the bronchoscope, a guide catheter and a steerable navigation catheter along the airway branches to the target site deep in the peripheral branches of the lung. Finally, the guide catheter is locked in place and special tools designed for use within the lungs are inserted to collect tissue samples for biopsy.

Electromagnetic bronchoscopy can even be used to sample multiple sites in the lung to enable pathologists to make a more accurate diagnosis and extent of the disease – something that is rarely possible with a needle biopsy. "Each time you perform a needle biopsy, the risk of lung collapse is 15 to 40 percent, so performing more than one makes the risk unacceptably high," Dr. Krishna says. "With electromagnetic bronchoscopy, the risk of lung collapse is about 3 percent."

If cancer is detected, the system can also be used to put markers inside the lung that computers can read and use to target beams of cancer-killing radiation during the treatment phase with unsurpassed accuracy, Dr. Krishna adds.

"Through electromagnetic bronchoscopy, I've been able to biopsy tissue I wouldn't have been able to reach otherwise," Dr. Chausow says. "In those cases we found cancer, and the patients were able to have surgery right away instead of just waiting and watching."

Visit the Mountian View Center's new Cancer Care Web site.