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NIH Clinical Center Devices Will Automatically Record Radiation Exposure

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Radiology and Imaging Sciences at the National Institutes of Health Clinical Center has taken a significant step to further safeguard clinical research patients at the NIH Clinical Center who are exposed to radiation during certain imaging tests. Computed tomography (CT) and positron emission tomography (PET)/CT equipment purchased by the Clinical Center will now be required to routinely record radiation dose exposure in a patient’s hospital-based electronic medical record.

“When a hospital or clinic patient receives a medication or a treatment, it is routinely recorded in the patient’s medical record,” said John I. Gallin, M.D., director of the Clinical Center, NIH’s clinical research hospital in Bethesda, Md. “The Clinical Center’s approach is an important first step in making it possible to more easily document and track information about a patient’s exposure to radiation.”

Today, electronic radiology information systems in hospitals generally do not collect or report radiation exposures. “CT and PET/ CT scanners do not currently forward data on radiation dose to our radiology information systems,” said Dr. David A. Bluemke, M.D., Ph.D. Bluemke is director of Radiology and Imaging Sciences at the Clinical Center.

The risk of exposure to low doses of medical radiation from diagnostic medical-imaging tests isn’t known, but very high radiation doses have the potential to cause cancer. The ability to keep track of an individual’s exposure to radiation through routine imaging tests is needed so that researchers can begin to determine if these exposures pose a health risk.

“The National Council on Radiation Protection and Measurements reported recently that Americans received seven times more radiation exposure from medical tests in 2006 than was the case in the 1980s,” said Ronald Neumann, M.D., chief of nuclear medicine and deputy associate director for imaging sciences at the Clinical Center. “CT and cardiac nuclear medicine studies accounted for much of this increased medical radiation exposure.”

Ultimately, radiation dosage could become a standard element of a universal electronic medical record used to assess radiation risk from life-long medical testing, the Clinical Center radiologists said. “Recording radiation dose is technically possible and an ethical imperative, ” Neumann said.

“The NIH Clinical Center also will require that newly purchased equipment allows patients to record their radiation dose exposure in their own personal health record,” Bluemke added. Online resources to help individuals organize their health information as a personal medical record are becoming more prevalent. Currently, patients can easily receive their diagnostic imaging studies records on CD-ROM, Bluemke said. The NIH Clinical Center’s imaging program will work with vendors who supply Clinical Center imaging equipment to develop software tools to extract the examination type, date, and radiation dose exposure from the CD-ROM, for uploading to a personal health record. As both the American College of Radiology and the Radiological Society of North America have recommended, patients should keep a record of their X-ray history.

About 25,000 CT and 1,250 PET/CT scans are performed at the Clinical Center each year as part of NIH research protocols. The clinical research hospital currently houses five CT scanners, and two PET/CT scanners.

Source: NIH, August 17, 2009

New Procedures Save Frostbite Victims from Amputation

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The standard treatment for frostbite has not changed in decades—re-warming the affected areas, with amputation in severe cases. Radiologists can now re-open recently frozen, clotted arteries with clot-busting and anti-spasmodic drugs, using imaging to visualize areas lacking blood flow and deliver drugs via catheter.

With severely frostbitten hands and feet, subjects in a recent test would typically lose their limbs to gangrene. In this case, Angiography, an X-ray exam of the arteries and veins, was used by interventional radiologists to verify loss of blood flow to a patient’s hand or toes. Intra-arterial catheters then supplied drugs to dissolve the blood clots and relax the arteries’ muscular walls.

A study released today at the Society of Interventional Radiology’s 33rd Annual Scientific Meeting confirmed that this treatment was significantly successful in preventing amputation and saving limbs.

"Previously severe frostbite was a one-way route to limb loss. This treatment is a significant improvement. We’re opening arteries that are blocked so that tissues can heal and limbs can be salvaged. We were able to reopen even the smallest arteries, saving patients’ fingers and toes," said George R. Edmonson, M.D., interventional radiologist with St. Paul Radiology in St. Paul, Minnesota.

According to Edmonson, severe frostbite or "freezeburn" looks like a second degree heat burn with large blisters, but it’s actually body tissue that’s been frozen and-in severe cases-dead, he said. "For half our patients who received the clot-busting drug Tenectaplase, this technique worked beautifully, saving all fingers, hands, toes and feet that otherwise would have been lost," said Edmonson, who has been treating an average of 6–10 frostbite patients each year for the past 10 years.

"Overall, in about 80 percent of the cases, it significantly improved patients’ outcomes. Within one to three days of treatment, we saw improvement," noted Edmonson, explaining that patients were followed for six weeks to assess their final outcomes.

Source: Society for Interventional Radiology

Researchers Advise Protecting Kidneys Before CT Scans

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Dyes containing iodine used to enhance CT scan quality can seriously harm kidneys; and a new study recommends that patients take an inexpensive pre-scan drug, called N-acetylcysteine which protects kidneys from damage. These ‘dyes’ or contrast agents put many older people and those with diabetes or heart failure at the most risk, and they have the most to gain from taking the drug.

The study is published in the Annals of Internal Medicine by researchers from the University of Michigan Health System, who were led by Aine Kelly, M.D., M.S., an assistant professor in the Department of Radiology at the U-M Medical School. The study is a meta-analysis of data from 41 randomized controlled studies that evaluated various drugs for their ability to protect kidneys: only N-acetylcysteine prevented contrast-induced nephropathy. Theophylline was not as effective, while furosemide actually raised kidney risk.

"Our goal is to improve the safety and quality of these common tests by studying drugs that reduce the risk of kidney failure," says senior author Ruth Carlos, M.D., associate professor of radiology.

Mild to moderate kidney damage occurs in one in four high-risk people who have CT scans, and in as many as one in ten people with normal kidney function. In some cases, it causes acute kidney failure. "Millions of people receive contrast agent each year, including most heart patients who have angioplasties and stents, as well as those having a CT scan. Contrast agent helps physicians see the things we need to see, but it also does pose a hazard to some people," says Kelly. "This drug, which is quick, convenient, inexpensive and widely available, with no major side effects, appears to be the best choice to protect those whose kidneys are most at risk."

In fact, Kelly says, patients who know they have weakened kidneys – also called impaired renal function – should speak up when their doctor orders a CT scan, angiogram or angioplasty, and make sure they get a tablet of N-acetylcysteine beforehand.

Source: Annals of Internal Medicine, 19 February 2008, Volume 148 Issue 4

CT Heart Scan Reliable for Detecting Blocked Arteries

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An international team of cardiac specialists, led by Johns Hopkins researchers, found that sophisticated computed tomography (CT) heart scans are almost as reliable as more invasive procedures.

The 64-slice CT scans, initially tested at Hopkins, will help cardiologists select patients who can avoid more invasive procedures. But the newer scans will not replace the cardiac catheterization, or coronary angiography, although perhaps 25% of the 1.3 million cardiac catheterizations performed annually in the U.S may be unnecessary.

In addition, the latest study showed that early detection with 64-CT would be a good forecaster of patients needing angioplasty or coronary bypass surgery.

Researchers chose 291 men and women over 40 years of age who already planned to have cardiac catheterization to check for blocked arteries. They were then checked to see who developed coronary artery disease, and who required subsequent bypass surgery. On average 91% of patients with blockages were detected by 64-CT scan, which also identified 83% without blockages. This accuracy, said researchers, enabled them to identify patients needing angioplasty or bypass surgery. More than 250,000 Americans undergo coronary bypass surgery annually.

"This study is the first step to realizing the full potential of CT imaging in predicting coronary artery disease, and these scans complement the arsenal of diagnostic tests available to physicians to prevent heart attacks," says cardiologist Julie Miller, M.D., who led the study at Hopkins.

"Use of 64-CT scans will dramatically improve our ability to detect and treat people with suspected coronary disease and chest pain much earlier in their disease," says cardiologist João Lima, M.D., senior investigator to the team whose findings will be presented at the American Heart Association’s (AHA) annual Scientific Sessions in Orlando, Florida. "Cardiac catheterization is still the gold standard for evaluating clogged arteries, but our results show that this test could easily be the best backup or alternative."

Source: Johns Hopkins Medicine

Improved IMRT Cancer Treatment Reduces Radiation Exposure to Healthy Tissue

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Recent studies by researchers at Montefiore Medical Center have shown that improved IMRT (intensity modulated radiation therapy) treatment provides far better patient care than standard radiation procedures because it safeguards healthy tissue surrounding cancerous tumors.

"We compared treatment techniques for cancers of the lung, abdomen, pelvis and head and neck, and were able to quantify just how much better IMRT was for patients in the studies than conventional radiation therapy," said Shalom Kalnicki, MD, chairman of the Department of Radiation Oncology at Montefiore.

Using the new IMRT technology, oncologists can now deliver thousands of precisely focused beams of radiation that follow the exact contours of a cancerous tumor. Today’s standard therapy uses cross-firing X-ray beams, and is not nearly as accurate.

A study of lung cancer patients showed that the average dose of radiation to the esophagus is reduced by 20 percent, and reduced by 30 percent to the area of the lung most critical for breathing.

"By developing and carrying out a tailor-made IMRT treatment plan for each patient, we reduced significantly the chance of having radiation beams harm healthy lung tissue and therefore impaired breathing," said Dr. Kalnicki.

In another study, Montefiore researchers used IMRT technology to treat patients with pancreatic cancer. Radiation dosage to the nearby kidneys was reduced by 38 percent, and radiation dosage to the normal bowel was also reduced by 38 percent.

A third Montefiore study used image guided adoptive planning, another advanced form of IMRT, to treat complex-shaped head and neck cancers.

The salivary glands, mandible, nerves and oral cavity lining were dramatically safeguarded using this method, resulting in significant improvement of patient quality of life.

Source: Montefiore Medical Center

Simple and Cost Effective Treatment of Calcific Shoulder Tendinitis

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A simple and cost effective way of treating calcium tendinitis of the shoulder was revealed by Spanish researchers,led by Dr. Del Cura, publishing in the American Journal of Roentgenology.

Calcium tendinitis presents as small calcium deposits (1 – 2 cm) on the rotator cuff of the shoulder in individuals over 35 years old. Often painful, some resolve spontaneously, but others persist and become disabling.

Traditional treatment involves shockwave therapy to the shoulder, and in worst case scenarios, surgery.

Dr. del Cura’s treatments, in contrast to surgery, are relatively non-invasive, and involve percutaneous needle lavage (with lidocaine or saline solution) guided by sonography.

In a study of 67 shoulders, 91% were "substantially or completely improved." Of note is that "transitory" recurrences were observed 15 weeks after treatment in 44% of shoulders that had previously improved.

Source: American Journal of Roentgenology (AJR 2007; 189:W128-W134)

Annual MRI Recommended for Some Women at Risk for Breast Cancer

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For some women who are at higher risk for breast cancer, the American Cancer Society’s has new guidelines that recommend those women get an MRI scan along with their annual mammogram.

While MRI’s are more sensitive and is likely to show more spots in the breast, it is often difficult to know if those spots are cancerous, and biopsy may be required. This is why the MRI is only recommended for high-risk women.

According to the American Cancer Society, an MRI screening in addition to mammograms is recommended for women who meet at least one of the following conditions:

  • they have a BRCA1 or BRCA2 mutation
  • they have a first-degree relative (parent, sibling, child) with a BRCA1 or BRCA2 mutation, even if they have yet to be tested themselves
  • their lifetime risk of breast cancer has been scored at 20%-25% or greater, based on one of several accepted risk assessment tools that look at family history and other factors
  • they had radiation to the chest between the ages of 10 and 30
  • they have Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome, or may have one of these syndromes based on a history in a first-degree relative.

High Res Heart CT Scans Risk for Patients

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With more and more technologies becoming available, doctors are finding that they must increasingly weigh the side effects of testing procedures.

After gaining FDA approval in 2004, CT angiography, a high resolution scan of the heart for blocked arteries, has been much more widely used. However, there is a risk–especially to younger people, as these scans expose patients to 20 times the amount of radiation as a mammogram.

Researchers reported that a CT angiography should be used sparingly, especially on young women, who have a 1-in-143 chance of developing cancer after just one high resolution CT scan.
The study was published in the Journal of the American Medical Association.