Spiral CT Scans Can Detect Lung Cancer Lesions Smaller Than a Sesame Seed
Susan McCormack | Inland Valley Daily Bulletin | February 6th, 2001

For decades, the traditional method of detecting lung cancer has been to take a chest X-ray after a patient shows symptoms of lung cancer, such as coughing, repeated bronchitis and weight loss. Unfortunately, most of these diagnoses come too late. According to the American Cancer Society, in 1995 the five-year survival rate for people diagnosed with lung cancer was 14 percent. A new use for existing technology is bringing hope to some physicians and patients and making headlines in national newspapers and TV shows, such as "Oprah."

According to the National Cancer Institute, more than half of U.S. hospitals own spiral CT machines - high-tech X-rays - for the purpose of determining how advanced a cancer is after diagnosis. But recently some hospitals and physicians have started promoting the scans for early detection of lung cancer before any symptoms are present. Millennium Imaging Medical Center in Montclair is one of a handful of centers in the area offering spiral CT scans.

Dr. Camiar Ohadi, a radiologist and professor at Western University of Health Sciences in Pomona, said he opened the office in September because he sees spiral CT scans as the way of the future. "The future of lung cancer screening to me is what mammograms have done to breast cancer," Ohadi said, referring to the fact since mammograms became commonplace 30 years ago, the breast cancer mortality rate has dropped almost 24 percent for women under the age of 50.

Ohadi said while chest X-rays pick up lesions almost half-an-inch long, spiral CT scans can detect lesions smaller than a sesame seed. "The cure rate is pretty poor for (lung) cancer overall, but the early detection cure rate is 70 percent, if the lesion is less than two centimeters and in the periphery of the lungs," he said.

During a spiral CT scan, a patient lies on a table and passes through an X-ray machine shaped like a donut hole. The patient takes a deep breath while the machine rotates and takes X-rays of his lungs. The entire scan takes between 15 and 20 seconds, and 3-D images showing cross-sections of the lungs appear almost instantaneously on a computer screen.

Most health insurances don't cover the $300 to $1000 cost of spiral CT scans for lung cancer screening. There are a number of reasons the companies and some physicians are hesitant to offer the scans as a screening tool, according to the National Cancer Institute. Scarring from smoking or other changes in the lungs can show up on the scans, making them difficult to interpret. A physician may misinterpret an apparent lesion and order an immediate biopsy, a risky procedure that can result in partial collapse of the lung, bleeding and infection, or chest surgery. Also, some experts fear a clean scan may give some smokers a false sense of security about their habits.

Dr. Joseph Unis, a radiologist with Pomona Valley Hospital Medical Center, which has had a spiral CT for about seven years, said research must show the screens reduce the likelihood of dying from lung cancer before this use of them becomes more widespread. "The studies are mixed regarding results. At least one study has cast some doubt about detecting cancer at an earlier stage in time, but not necessarily altering its final outcome," he said. "That's why we're in a wait-and-see mode for fear of being perceived as trying to take advantage of the public. We have the capability, and we're waiting to see the scientific studies."

The National Cancer Institute launched a study last year to conclusively answer this question. But Ohadi, who is tracking two suspicious lesions in his own father's lungs, said he believes the costs outweigh the risks. "In my opinion, leg work is being done, and eventually the numbers on mortality will justify what we're doing today," he said. "That's why I'm excited to get the word out now while we're waiting for the data on mortality. We can detect cancer and save lives now instead of waiting 10 to 15 years to get the answers."