Consult Internal Manual Medicine

Computed tomography (CT or CAT) scans help doctors detect everything from cancer to kidney stones. But some physicians are raising concerns about the safety of such procedures — most notably, an increase in cancer risk. A CT scan packs a mega-dose of radiation — as much as 500 times that of a conventional X-ray. If your doctor orders a CT scan for you or your child, should you think twice?

Absolutely, say researchers behind two recent studies that sound the alarm about the increased cancer risk associated with multiple CT scans. In the first study of its kind, physicians at hospitals in Florida and Washington, D.C., evaluated the medical-imaging records of 1,243 randomly selected patients to calculate just how much radiation each patient had sustained in the past five years. Although CT scans were the biggest source of radiation, other offenders included X-rays and mammograms. The results of the study, presented in May at the annual conference of the Society for Academic Emergency Medicine, were disturbing: the average patient had received 45 millisieverts (mSv) of radiation. (The typical chest X-ray dispatches 0.02 mSv of radiation.) And 12% of patients had gotten more than twice that amount — 100 mSv or more. "Our focus is to bring awareness to the fact that people are getting large doses of radiation and it's not innocuous," says Timothy Bullard, the study's lead author and chief medical officer at Orlando Regional Medical Center. "We want people to use the technology appropriately."

"Appropriate" is the key word — especially since a review study published last November in the New England Journal of Medicine determined that as many as one-third of all CT scans performed in the United States are unnecessary. The authors take issue with the "perhaps 20 million adults and, crucially, more than 1 million children per year in the United States [who] are being irradiated unnecessarily." Part of the problem, the authors say, is that patients are being prescribed multiple, unneeded CT scans, a predicament that could be avoided with better communication between physicians. "Having the same CT scan twice is ridiculous," says David Brenner, the review's lead author and director of the Center for Radiological Research at Columbia University Medical Center. "There is no excuse." In one of the review's highlighted studies, among patients undergoing CT scans, 30% were on their third scan, 7% had five or more, and 4% had more than nine. Also to blame: doctors increasingly practicing defensive medicine. "There is an underlying philosophy that you're at fault if you miss anything," says Bullard. "The goal is to be perfect every time." Plus, he notes, CT scans have no immediate negative side effects. "They are quick, painless, and send patients away with the sense of satisfaction that everything's been done."

Exactly how much radiation is too much? Because CT scans came into vogue in the 1980s and radiation-induced cancer takes roughly 20 years to develop, long-term studies of CT scans and cancer are still under way. But scientists are already anticipating future health implications. Indeed, researchers found a population of 25,000 Japanese post-atomic-bomb survivors who were exposed to roughly the same amount of radiation as two CT scans. Based in part on those studies, the Food and Drug Administration estimates that an adult's lifetime risk of developing radiation-induced cancer from a CT scan is roughly 1 in 2,000. Worse, the risk for children is even higher.

Compared with adults, children are more sensitive to radiation because they have longer life expectancies and because their cells divide more rapidly, making their DNA more vulnerable to damage. A child's risk of developing a fatal cancer from one CT scan is as high as 1 in 500. Although newer machines can be adjusted to deliver up to 50% less radiation for children and small adults, a 2001 study published in the American Journal of Radiation showed that radiologic technologists (RT) rarely make those adjustments. "Changing technical factors is very easy. It just requires a little thought and a few extra seconds," says Michele Scoglietti, a spokesperson for the American Society of Radiologic Technologists. "But I think there are many RTs who are either not trained to vary the technique, don't know how, are in a hurry or are just lazy."

When doctors first ordered a CT scan for Jen Houck's six-month-old daughter in 2003, the new mom was more worried about the risks of anesthesia (used to keep children from squirming in the machine) than of radiation exposure. In 2006 and 2007, her daughter, now 5, had two additional CT scans, 6 months apart, for what doctors initially thought was a growth abnormality. They've since determined the child was perfectly healthy. "All that, just to find out her head is bigger than normal," says the 27-year-old mother of two in Boone, North Carolina. In hindsight, Houck wishes she had done things a bit differently. "I would have asked more questions about the necessity for a third scan so soon after the second." She also says no one mentioned the option of a low-dose scan, and she has no idea how much radiation her daughter received. "I wish I'd known to ask the question."

So what should you ask, if a doctor recommends a CT scan for you or your child? Brenner suggests the following: is a CT scan really necessary? Might a test that doesn't involve radiation, such as an ultrasound or MRI, do the job? In some cases, a CT scan is absolutely required — for example, for diagnosing severe head trauma or internal injuries, for acute abdominal pain, or to diagnose an existing cancer. If your doctor schedules you for a scan, call ahead to see if you can bring a flash drive. That way you can take an electronic copy of your CT scan to go, and may be able to avoid another scan later, should you move or change doctors. (A hard copy of the scan is bulkier, but may also be an option.) If your child needs a CT scan, ask the technologist to put the machine on pediatric-appropriate settings. For more information on kids and CT scan safety, visit the http://www.pedrad.org/associations/5364/ig/.

Blue leads an active lifestyle: she runs four times a week around an enormous park in her hometown of Memphis, Tenn.; she likes playing Frisbee and loves swimming. But one day last November, Blue started limping — which was odd because the German shepherd seemed fit and was only 3 1/2 years old. "She wasn't recovering as quickly as normal from a trek in the park. I thought that was just a sign of aging," says her owner Twila Waters, 43, with a wry chuckle.

In fact, Blue had hip dysplasia, a fairly common and sometimes crippling degenerative condition in dogs and cats. The cure — a complete hip replacement — would keep Blue in recovery for up to six months. So while Waters mulled the surgery, Blue's regular veterinarian sent Waters to see another local vet, Kathy Mitchener, who was trained in acupuncture, to treat Blue's pain. But Mitchener had a better idea. She offered a cutting-edge stem-cell transplant, a therapy not yet available to humans, that would potentially help Blue's hip repair itself.

The treatment took just two days last January. Mitchener had recently become certified to perform the stem-cell treatment, pioneered by the company Vet-Stem based in San Diego. She removed some fatty tissue from the dog's abdomen and shipped the sample to Vet-Stem's labs, where technicians used centrifuges to extract stem cells from the tissue. The cells were shipped back the next day, and Mitchener injected them into Blue's failing hip, where they adapted and developed into the healthy cartilage and tendon cells the animal needed. Within 36 hours, Waters says, "Blue was moving well, and you could see an ease in her gait." Vet-Stem kept a frozen store of Blue's stem cells, in case she suffers a relapse or has another orthopedic injury, but for now, Blue is fully cured and back to running and swimming and playing with her friends.

Vet-Stem's therapy is just the newest frontier in the booming field of alternative veterinary medicine — which includes acupuncture, chiropractic and aquatic therapies and traditional Chinese herbal medicine — an industry driven by pet owners who are increasingly willing to do or pay whatever they can to help their ailing pets. In the past decade, the number of vets who completed a 156-hr. training course given by the International Veterinary Acupuncture Society (IVAS) has quadrupled. IVAS also recently added courses in herbal and food therapy, and Tui Na, a manipulative treatment like chiropractic. According to IVAS spokeswoman Vikki Weber, 10% to 20% of the society's trainees end up quitting Western medicine altogether. "There are other possibilities out there besides pills or a doctor's knife," says Mitchener, a veterinary oncologist who incorporated alternative treatments into her practice four years ago.

Most progressive veterinary therapies are inspired by human health care. Burton Miller, who runs the Animal Wellness Center in Huntington Station, N.Y., became a practitioner of Eastern medicine for animals after suffering a skiing accident in 1996. He began reading up on alternative therapies for his injury and decided to apply the same kind of medicine to his animal patients. "I announced to my [clients] that everything I had ever told them was wrong," he says. Those pet owners promptly abandoned him, but today he has a thriving practice in which acupuncture and homeopathic medicines are the most common courses of treatment. (A veterinary visit including acupuncture with Miller costs $65 — about what a human acupuncturist in Manhattan charges.)

Unlike these older, more popular therapies, Vet-Stem offers — for the time being — better medicine to animals than any allowed for their owners: even though it does not use controversial embryonic stem cells, the fatty-tissue stem-cell transplant has not yet secured FDA approval for use in humans. But pets are reaping the benefits in droves. Since Vet-Stem began offering its online certification course in January, more than 1,000 vets have signed up to take it, many at the urging of their patients' owners. The FDA has so far approved the treatment for animals' orthopedic problems in tendons and ligaments, and for bone fractures and arthritis. Vet-Stem says that some of its patients begin to feel better the same day, and most improve within a week. About 20% see no progress at all, but the company hasn't received reports of negative effects and it says it didn't see any in its earlier clinical trials. Vet-Stem is now testing stem cells to treat kidney disease in cats and liver disease in dogs.

The cure-all doesn't come cheap. A cycle of stem-cell treatment generally costs $2,000 to $4,000, including the extraction, surgeries and follow-up. (Canine hip-replacement surgeries, however, can be about four times as expensive.) Robert Harman, Vet-Stem's founder, says that because of the steep price tag, he initially thought wealthy horse owners would be his primary clientele. "Turns out there's not quite the same emotional attachment to horses as in the small-animal world," Harman says. "It used to be if your dog got sick, you just got a new dog. Now people want the best care, and they want to pay for it." At the start of the year, Vet-Stem's patient pool was 90% horses and 10% dogs. By the end of 2008, Harman estimates those numbers will shift to 60% dogs, 10% cats and 30% horses — no doubt aided by word-of-mouth praise from pet owners like Waters. "It's comforting for me to know I've done what I can to alleviate Blue's pain," Waters says. "She loves to play so much that fixing her hip really improved both our qualities of life."

When it comes to your health, being your own doctor usually isn't the smartest idea. But new evidence suggests that if you're one of the 1.5 billion people around the world with high blood pressure, you may be better off taking control of your own treatment than relying on a doctor.

Researchers at Group Health in Seattle, a nonprofit health care system that helps patients find appropriate care and coverage, found that patients with high blood pressure who were given access to a pharmacist and a Web-based self-monitoring system were able to control their hypertension better than patients who underwent traditional physician care, which involved several office visits per year. The self-check group was able to drop nearly 30 points off its readings on average over the year-long study period.

"Controlling hypertension is particularly suited for this kind of application of technology," says Dr. Daniel Jones, president of the American Heart Association and dean of the school of medicine at University of Mississippi Medical Center. "We have been using the standard approach for many years with disappointing results. Only about one-third of patients with high blood pressure have it controlled properly, and among those on treatment, only half are able to control their blood pressure."

Among the more than 700 patients in the study, 258 were put into a standard physician-care group, with regular office visits. The remainder were divided into two self-care groups: in the first, patients had access to their electronic medical records and were instructed to measure their own blood pressure two to three times each week; patients then sent the results to their physician, who recorded the readings in files the patients could review. In the other group, patients performed the same self-measurements, but were also provided access to a pharmacist who evaluated their readings and helped patients adjust medication dosages as necessary. At the end of a year, twice as many people in the home-care-only group lowered their blood pressure to under 140/90 mmHg (the clinical cut-off for high blood pressure), compared with the standard-care group. But the patients with access to a pharmacist saw the most dramatic decline in blood pressure — a nearly 28-point lower measurement in the top number, or systolic reading, compared with the traditionally treated group. "We were surprised that the Web-based model had such a good effect, especially in those with more difficult-to-control hypertension," says lead author Dr. Beverly Green. "These people were three times more likely to get their blood pressure under control with the help of the pharmacist than those in the standard-care group."

It may be that hypertension is a particularly good condition to treat with home-based strategies, say both Jones and Green. Like weight-loss support groups and exercise programs, pharmacist-assisted self-monitoring keeps patients motivated and compliant with their treatment — and, in some cases, may prevent the disease from becoming serious enough to require pharmaceutical treatment. Most physicians also acknowledge that more frequent monitoring is likely more accurate: doctors take only one or two blood pressure measurements a year, when patients come into the office, but those readings can be influenced by a patient's stress or tenseness in the doctor's office (the "white coat syndrome"), and blood pressure can vary from day to day or even during a single day, depending on what a person is experiencing. "If somebody comes in and tells me they rushed in because they were late, and their blood pressure is high, I give them a pass," says Dr. Eric Peterson at Duke University. Individual readings taken a few months apart can also be difficult to interpret, he says. But measurements that patients take at home, several times a week, offer a more accurate picture of where their blood pressure stands.

Still, it will take some fundamental changes in the way health care is delivered before the study findings can be instituted. For one thing, relying on Web-based systems could potentially widen the gap in access to health care between wealthier patients and those who can't afford computers. In addition, not every physician will want to monitor e-mails or conduct virtual exams without being reimbursed for his or her time and expertise. "Our overall health-care system is poorly designed for prevention," says Jones. "We need to look again at the whole system to find effective and efficient ways to deliver this kind of management for chronic risk factors like hypertension."

If you had $75 billion to spend, how would you save the world? Would you invest it all in alternative energy research, to fight global warming? Would you revamp America's border and port security, to fight terrorism? Would you sign Kobe Bryant, Paul Pierce and Tim Duncan for the Philadelphia 76ers? (My personal choice.) Most of us might would make such a decision based on emotions — witnessing the pain of hunger, or experiencing the fear of nuclear terorrism. But what if there were a way to calculate the exact value of global priorities, a way to figure out just how much human suffering we could alleviate per dollar spent?

That's how the Copenhagen Consensus works. Over the past two years, some of the world's top economists have been crunching the numbers on the most efficient way to spend that $75 billion, roughly the sum total of global foreign aid budgets. Led by Bjorn Lomborg — an idiosyncratic author best known for his skeptical views on global warming — the organization last month gathered eight major economists, including five Nobel Prize winners, to come up with an answer. The results are surprising. According to the numbers, the biggest problem facing the world isn't global warming or terrorism. It's malnutrition in the developing world, and it can be sharply reduced for as little as $60 million a year, by supplying basic micronutrients for 112 million kids who lack essential vitamins. According to the Copenhagen Consensus's figures, that $60 million would pay back more than $1 billion in benefits — better health, fewer deaths, more worker productivity. "It's a matter of cost and benefit," says Lomborg. "These are the best problems with the best solutions." (Hear Lomborg talk about the Copenhagen Consensus and climate change on this week's Greencast.)

In its work, the Copenhagen Consensus poses a useful question: what if instead of trying to tackle the world's myriad problems in a piecemeal fashion, we focused our efforts tightly on where we could get the most value for our dollar? It's a very economist — and unglamorous — way of looking at the world. So one of the group's top global priorities is salt iodization for the poorest regions of South Asia, Africa and Eastern Europe. (An estimated two billion people in the world suffer from iron deficiency, which can lead to goiter and which can be prevented with iodized salt.) For $19 million, this problem can essentially be solved. Delivering salt to the developing world isn't as dramatic as saving the polar bear, but the benefit of reducing human suffering is real. "It shouldn't be about who has the cutest animal," says Lomborg. "It's about the value of life."

Lomborg says the Copenhagen Consensus tends to focus on problems that have clear, applicable and economical solutions — which explains why climate change, despite its potential for long-term catastrophe, ranks beneath threats like parasitic worms and malaria on the group's list. To Lomborg — who says he believes in global warming but is skeptical of its severity — fighting climate change just isn't a good way to spend our money. We know for certain that supplying vitamins to impoverished children will save lives — but we don't know for sure that spending billions to reduce carbon emissions will have the same clear effect. One is a sure thing, and the other is a bit of a gamble — and since the world has limited resources for doing good, the thinking goes, best to opt for the sure thing when lives are at stake. It's a position that's earned Lomborg the enmity of the mainstream environmental community — the green website Grist.org once called him "Bjorn Loser" — but he's unshakable. "You give the most to the solutions that do the most good," says Lomborg, who believes that more effort needs to be put on adapting to climate change, rather than simply trying to stop it. "There's definitely a case of hype and one-sidedness on the climate debate."

To some degree, Lomborg is right. It would be a mistake to let fears over warming in the future overwhelm the endless list of ills today, and at times it does seem as if environmentalists care more about climate in the abstract than real human suffering. But not every threat can be broken down in terms of dollars and cents. Climate change is a unique challenge because if the dire predictions turn out to be right, our planet — and our civilization — might no longer be recognizable. We remain frustratingly incapable of nailing down how much warming we'll experience over the next century, or what the exact effects of climate change will be. But we know more every day, and the evidence, while not flawless, is frightening. By all means spend the money to halt malnutrition, or improve reproductive rights, or clean up water sanitation. But if I were asked to come up with the world's most pressing challenge, I wouldn't need to crunch the numbers. It's climate change — because we only have one Earth.

Gardasil has been a shot in the arm for pharmaceutical giant Merck. The company had been reeling from the withdrawal of its anti-arthritis drug Vioxx because of increased risk of heart attacks and resulting lawsuits. Now, however, Merck's new vaccine against the human papilloma virus (HPV) — aimed at combating cervical cancer — has been deployed worldwide, earning an estimated $1.5 billion in sales. But the drug is coming under increasing fire from anti-vaccine activists. Already very vocal about childhood innoculations, now they are expressing concern about the effects of Merck's drug on young girls, a primary focus of the company's big ad campaign.