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Double-CT radiation a concern

By Dave Gulliver
7/9/2010 © Health News Florida

A type of medical scan that delivers a double dose of radiation to the patient is recommended for only a small number of conditions. But some Florida hospitals perform the scans on more than half of their patients, a new study shows.

The new data on combination or double CT scans of the chest and abdomen were released this week by the Centers for Medicare and Medicaid Services (CMS). Available on the government’s Hospital Compare website, they show the percentage of scans at hospital outpatient departments.

At a handful of facilities in Florida, the data show, double scans account for two out of every three outpatient abdominal or chest CT studies.

“We’ll look into the data and see what the trends are. Certainly some of these scans are unnecessary,” said Dr. Barry M. Straube, CMS’ chief medical officer.

Venice Regional Medical Center in Sarasota County conducted a double abdominal CT scan on nearly nine out of 10 patients, the data show. (See hospital list for abdominal CT).

Others that hit the 70-percent mark for double CT's of the abdomen were South Florida Baptist Hospital in Hillsborough County near Tampa and North Okaloosa Medical Center on the Gulf Coast in the Panhandle. Sebastian River Medical Center in Indian River County on the Atlantic Coast came within a hair's breadth. 

North Okaloosa Medical Center shows up again on the chart for double CTs of the chest, highest in the state at 69 percent. Healthmark Regional Medical Center in the Panhandle's rural Walton County was also above 60 percent, more than twice the rate of the next highest hospital. (See hospital list for chest CT).

While CMS has not precisely defined the threshold for what it considers too many combined scans, federal agencies and medical groups say they are worried about needless exposure to radiation. 

Computed tomography scans are booming -- about 70 million were performed in 2007, up from 3 million in 1980. That has led to scrutiny from several government agencies and medical groups concerned about patients’ exposure to radiation. The Food and Drug Administration announced in February it was taking steps to increase regulation of all CT scans. 

The National Quality Forum, a closely followed medical standards group, in 2008 endorsed a measure that called for minimizing use of the combined chest CT scans. It has yet to address combined abdominal CT scans.

CT scans are essentially a series of x-rays at different angles that produce a three-dimensional image of the body. They require about 11 times more radiation exposure than a normal x-ray test, CMS said.

A combination CT study is two CT scans, one scan with a “contrast” substance, akin to a dye, to help organs stand out in the image, and another scan with no contrast. That doubles the radiation exposure, and contrast agents also carry risks of allergic reactions and kidney damage.

To be sure, CT scans and other imaging tests have great value, said Dr. Richard Morin, a medical physicist and radiation safety expert at Mayo Clinic in Jacksonville.

“If an imaging study is ordered appropriately, then the benefit to the patient outweighs the risk,” he said.

But he said doctors face pressure to misuse the scans. One reason, he said, is “entrepreneurship,” when a physician practice owns and operates its own equipment and has an incentive to over-order tests. The CMS data does not look at physician-owned facilities.

Another is fear of malpractice lawsuits, especially in emergency cases, he said. “If they didn’t do the imaging and it turns out the patient had an injury or disease, it puts them in a difficult position,” he said.

Finally, patient demand is also a factor. “Sometimes physicians order exams because the patient won’t have it any other way,” he said.

It adds up to thousands of potentially unnecessary scans.

CMS looked at outpatient abdominal and chest CT scans and calculated a ratio of the double scans to all scans. The agency said the nearer the double-scan percentage is to 100 percent, the greater the likelihood that the center is doing too many.

The Hospital Compare data examined nearly 200,000 CT scans in Florida, of which about 28,000 were combined scans. 

Miami-Dade’s Mercy Hospital had the lowest percentage of double scans, at 8.7 percent. The median rate for Florida hospitals was 13 percent.

For chest CT scans, the 152 hospitals studied had double scans in less than 3 percent of cases, and 13 reported no combination scans at all. Only four posted exceeded 30 percent.

Florida hospitals were far from the nation’s worst. The state ranked 13th-highest for its rate of combination abdominal CT scans and 24th-highest for the combination chest CT scans.

The variety across Florida hospitals appears to stem from their individual policies, usually set by their medical staffs.

At Venice Regional, a combination CT for abdominal scans was standard protocol in 2008, the year CMS examined, said Rob Bruce, director of radiology. The policy changed last year upon recommendation from the hospital’s medical staff, he said.

Dr. Gene Erquiaga, a radiologist based in Venice, said hospitals’ high number of combination abdominal CT scans probably is linked to a high proportion of elderly patients. Combination scans are particularly powerful in spotting liver cancer, a common problem in the elderly, he said, while the danger from radiation is reduced because those tumors takes decades to develop.
 
But many profitable imaging centers routinely perform the combination scans to increase billings, he said, while Medicare rarely refuses to pay for those scans.
 
“Sometimes complete exams have a medical reason so we can see how something looks without and with contrast enhanced blood flow,” he said. “Sometimes complete exams have no medical reason and are performed in order to charge more.”
 
Teaching patients about when procedures are effective is crucial, said Dr. Keyser Enneking, chair of the quality committee at University of Florida’s Shands HealthCare System. “Much of what we do is driven by what the patient wants,” she said. “A lot of what we need to do in healthcare reform is patient education.”
 
For now, the Hospital Compare imaging data appears to fall short as an educational tool. Its sections on heart attack, heart failure and pneumonia care all clearly indicate where a hospital is performing better or worse than its peers, but the imaging
data lacks that clear guidance.
 
Despite its weaknesses, Straube said he was comfortable releasing the data because it gave people information to start asking questions. 
 
The leading hospital industry advocate also supported the data’s release. “On the imaging measures, there’s more for us to learn,” said Rich Umbdenstock, president of the American Hospital Association.
Shands’ Dr. Enneking said that hospitals and doctors pay attention when their score is noticeably different from their peers.

“Is this going to embarrass people? Absolutely. But it will drive them to make their data better,” Enneking said.

“We need to step back and ask ourselves, ‘Do we really need this?’ …Because a lot of what we do doesn’t make the patient better.”

--Dave Gulliver is an independent journalist in Sarasota.