What Lies Within

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adiation risk is probably the weakest argument against whole-body scans. Freilich says the dose from one of his scans is only 6.8 mSv, about 20% higher than occurs in a mammogram. In any case, it's debatable whether exposure to low-level radiation is harmful. Certain groups exposed to higher-than-average radiation - such as flight crews - have cancer rates no higher than the general population. "If anybody can produce a case of cancer caused by CT scanning," says Freilich, "I'll become a plumber."

Anti-scanners are on firmer ground hammering the implications of "false positives." That spot on the man's lung is probably nothing, but it must be checked out. Now fretting about cancer, he undergoes any number of tests. "There are dangers involved in following these blind alleys," says Prof. Alan Coates, chief executive officer of The Cancer Council Australia: for example, scores of Australians die every year from complications of anesthesia. Though clients receive no rebate on whole-body scans, which cost about $A500, doctors estimate that the average cancer scare takes about $1,000 from the public purse. "The scanners can point to individuals who've had early detection of cancers and been cured," says Dr. Derek Glenn, of the Royal Australian and New Zealand College of Radiologists. "That's wonderful . . . but our responsibility is to look at the issue for the population as a whole." Doctors also question whether people cleared by body scans are justified in feeling peace of mind. The heart component of the scan, for instance, provides data on only one predictor of heart attack.

A chink in the false-positive argument is that for years authorities have urged prompt action on health concerns. Don't be shy, we're told, see your doctor - nearly every disease can be beaten if it's caught early. The legal principle that better 10 guilty people go free than one innocent be convicted might have a medical equivalent: "If ultrasounds are performed on 20 of my patients with an ovarian growth, and 19 turn out to be harmless and one is cancer, well, I'm a saint," says Freilich.

Opponents respond that many of Freilich's clients are just wealthy hypochondriacs who have pressured their G.P. (last year's N.S.W. government crackdown included a ban on operators giving scans to people without an independent referral). But Freilich says 95% of his clients are "smokers, drinkers, people who haven't looked after themselves." Nearly everyone who wants a scan has some "relevant medical history . . . but I can tell you that people who felt completely healthy have been found to have life-threatening disease." The third argument against scanning is the most interesting. According to acpsem's position paper, "There is no proven evidence to date that early detection of life-threatening disease by CT has a significant positive effect on patient outcome." In other words, while Total Health Screening and similar practices overseas have detected disease in people, there's no proof they have lived longer or better as a result.