First Studies of Whole-Body Screening CT Mixed

April 1, 2003
Oncology NEWS International, Oncology NEWS International Vol 12 No 4, Volume 12, Issue 4

CHICAGO-According to early experience at one imaging center in Massachusetts, whole-body screening CT is attracting individuals who may benefit from early detection of disease, such as current or former smokers and persons with other risk factors for cancer and heart disease. These researchers found that whole-body screening CT is not, as some have feared, leading to additional unnecessary invasive and expensive testing. However, a California study found that nearly half of persons with an abnormality found on screening required follow-up testing.

CHICAGO—According to early experience at one imaging center in Massachusetts, whole-body screening CT is attracting individuals who may benefit from early detection of disease, such as current or former smokers and persons with other risk factors for cancer and heart disease. These researchers found that whole-body screening CT is not, as some have feared, leading to additional unnecessary invasive and expensive testing. However, a California study found that nearly half of persons with an abnormality found on screening required follow-up testing.

Further, the California study suggests that the procedure may be costly to patients who may not receive the reassurance they are looking for in return for an $800 to $1,000 charge, as well as to insurers who pay for laboratory and other follow-up imaging tests.

Speaking at the 88th Annual Meeting of the Radiological Society of North America (RSNA), Giovanna Casola, MD, recommended that whole-body CT screening should be confined to individuals who are at the highest risk for serious disease, and it should be provided in a facility that also can perform any indicated follow-up tests. Dr. Casola is professor of radiology and chief of body imaging, University of California, San Diego (UCSD), and lead author of a study on whole-body screening CT at a private outpatient imaging center in San Diego.

She also suggested that the facilities that provide whole-body screening CT should be sure to use contrast media for imaging the abdomen in patients with a previous known malignancy. "If we are truly trying to find cancers, it is okay to do a CT scan in the chest without intravenous contrast. But in the abdomen, you will miss cancers if you don’t give intravenous contrast, and therefore a negative examination would give patients a false sense of security," she said.

San Diego Center Study

Of 1,192 patients scanned in Dr. Casola’s study, 86.5% had at least one abnormality, and 13.5% had a totally negative exam (RSNA abstracts 319 and 320). Of the patients with an abnormality, 54% had benign findings of only minimal clinical significance that did not require further screening. Among the 46% who had more substantial abnormalities requiring follow-up, 15% had significant benign disease such as emphysema and 25% had a possible malignancy.

Of the 25% of persons screened who were classified as high risk, 24% had a suspicious lesion in the chest or abdomen that required additional testing, but less than 1% had a potential malignancy or life-threatening condition such as an aortic aneurysm, Dr. Casola said.

A total of 4% of patients had a known cancer and were undergoing whole-body screening CT to rule out spread of the disease. However, a whole-body screening CT that does not involve the administration of contrast material could be misleading to patients because a negative scan would not exclude metastatic disease, she emphasized.

Patients under age 40 had few findings; only 9% required additional diagnostic work-up. No one under age 45 had findings that were highly suspicious of malignancy. Dr. Casola concluded therefore that whole-body screening CT is not cost-effective for asymptomatic, low-risk patients under age 45.

Patients age 45 years and older had a four times greater risk of having significant disease than younger individuals. Overall, in the older age group, between 40% and 45% required additional imaging, usually an additional chest CT to look for lung nodules. Each of these additional chest CT scans translates into another four scans during an average 2 years of follow-up, to make sure the nodule does not increase in size, she noted.

Even though the patients are paying for the screening examinations up front, the question remains as to who pays for the follow-up tests that may be needed to work up, for example, a lung nodule. "Right now, insurance carriers have been paying for these tests," Dr. Casola said, but if we screen the population at large, this would add a very significant cost for the health care system as a whole."

Dr. Casola emphasized that centers performing whole-body screening CT should be able to provide further tests of any abnormalities that are uncovered by the test. "Patients should be able to go to their institution or a sister institution and get follow-up testing. Patients should not be left on their own to find a center to do the follow-up scans," she said. Screening centers also need a system of communications that assures that patients connect with a primary care physician for follow-up care.

Dr. Casola also said that screening centers must participate in outcomes studies. "Right now, there are no outcomes. What happened to the patients? Did they actually have cancer? Did the surgery actually show there was significant disease?" she asked.

These and other investigations are needed so that imaging centers can give patients realistic expectations about the value and the process of whole-body screening CT. "It is important for us to tell patients, ‘Look, 50% of the time we are not going to be able to give you a clean bill of health right off the bat. We are going to tell you that you may need other testing.’ That is something they should be told up front," Dr. Casola said.

Massachusetts Center Study

Beth Israel Radiology Foundation, Inc, Boston, Massachusetts, opened the BeWell Body Scan whole-body screening CT program in May 2002, and in its first 6 months, it attracted a well-cared-for population. On average, most women visiting the center had seen a physician within the previous 4 months, and most men had seen a physician within 9 months. "So these are people who are getting health care through the traditional system," said Max Rosen, MD, associate professor of radiology, Harvard Medical School and medical director of BeWell Body Scan.

In a telephone survey conducted by Dr. Rosen and his colleagues to determine the needs and demands for whole- body screening CT, 79% of 450 heads of households polled said they were concerned about developing cancer, 60% feared a possible heart attack, and 48% reported that their insurers and doctors were not doing enough to provide testing for them (RSNA abstract 317). After an explanation of whole-body screening CT, 82% said they would be interested in such screening.

Although some of the patients who visit the BeWell Body Scan center are using whole-body screening CT in the traditional sense of screening—to detect preclinical disease—others wish to confirm or validate unresolved complaints or detect conditions that may be overlooked during a routine physical examination, Dr. Rosen said.

Others are seeking testing as a means of empowering them to work within the managed care system to reduce their risk of disease. "Many patients are using the service to motivate themselves to change their behavior. When I ask people why they have come, they say, ‘I’m here because I want to stop smoking’ or ‘I want to lose weight,’" he said at an RSNA press conference. (These and other preliminary data from the first 6 months of operation of the BeWell Body Scan center were not formally reported at RSNA.)

Between 15% and 17% of the patients scanned at the BeWell center were current smokers and 41% to 46% were former smokers. "We find this encouraging because this is a group that might benefit most from having the scan," Dr. Rosen said. A total of 64% of the patients had a family history of cancer, and 55% had a family history of heart disease.

Although 25% of patients had hypertension and 36% had hypercholesterolemia, only 2.5% had known heart disease. "The idea of screening is to look at an asymptomatic population, and as far as heart disease is concerned, we are screening people who do not know they may have heart disease," Dr. Rosen said.

One of the concerns is that whole-body screening CT would lead to unnecessary invasive procedures. However, in Dr. Rosen’s group, only 3% of patients had a biopsy or surgery as a result of screening findings. Half of those screened did not require any follow-up, 25% were referred for follow-up chest CT, and 9% were sent for a cardiology evaluation with or without a stress test.