Guidelines in Radiation Exposure, Tracking, Dose Reduction Are Hot Topics at AAPM

July 29, 2009 - The latest post-9/11 standards for tracking radioactive materials, the long-term trends in radiation exposure to physicians and the public, and some of the latest ideas for minimizing medical radiation dosage to children, adults and health professionals are focal points at the American Association of Physicists in Medicine (AAPM) 51st Annual Meeting, taking place from July 26 - 30, 2009 in Anaheim, Calif.

Thousands of scientists and board-certified health professionals from the field of medical physics have gathered to present the latest technologies in medical imaging and radiation therapy and discuss the ethical and regulatory issues facing those fields today.

Included below are a few of the presentations related to radiation exposure and radioactive materials.

ARE RADIOLOGISTS AT RISK?
Studies of people exposed briefly to high levels of radiation (e.g., the atomic bomb) have helped to establish the link between radiation and cancer, but their relevance to radiologists - whose occupation brings them into contact with low levels of radiation for long periods of time - is uncertain. Amy Berrington of the Johns Hopkins School of Public Health will present the results from and limitations of recent epidemiological health studies and predictions of cancer rates among radiologists and radiographers in the United States, China, and the United Kingdom, as well as new data from an ongoing study of physicians who perform fluoroscopic procedures, which use X-rays to visualize the inside of the human body in real time. (8:30 a.m. on Thursday, July 30 in room 213A).

REPORT ON U.S. PUBLIC EXPOSURE
U.S. citizens are exposed to nearly six times more radiation today than they were in 1987, according to data summarized in the newly-released National Council of Radiation Protection and Measurements (NCRP) Report No. 160. Mahadevappa Mahesh of the Johns Hopkins University School of Medicine discussed where this radiation is coming from, with a focus on medical technologies like CT scans and nuclear medicine.

KEEPING TRACK OF RADIOACTIVE MATERIALS
Launched in late 2008, the National Source Tracking System closely tracks an inventory of high-risk radioactive materials in the United States. Angela Randall of the United States Nuclear Regulatory Commission described the deployment and operation of this security network and will provide an opportunity to receive feedback from the audience.

REDUCING RADIATION DOSES IN CHILDREN
The developing organs of children are more sensitive to radiation exposure than those of fully-grown adults, which makes minimizing dosage a major priority of pediatric medicine. Parinaz Massoumzadeh of the Washington University School of Medicine discussed the results of a study in which 19 radiologists scrutinized 176 CT scans taken from 16 children (half of whom had abnormalities that should be visible in the scan). Some of the CT scans they left as they were. To the others they added noise -- to simulate a scan taken at a lower dose. This study showed that the radiologists could identify the abnormalities just as well on scans with doses of radiation that were 50 to 80 percent lower than those typically used.

RADIATION GUIDELINES
Updated recommendations for calculating and regulating the effects of radiation on living tissue were released in 2007 by the International Commission on Radiological Protection. Drawing on this report and a recent review by the Nuclear Regulatory Commission (NRC), Dr. Kimyata Morgan-Butler of the NRC will discuss some of the options for incorporating the latest scientific models used to assess risk and potential new limits on occupational radiation exposure into the regulations in the United States.

SAFETY EQUIPMENT CAUSES BACK PROBLEMS
Radiation is not the only risk for medical professionals who use X-ray machines in the clinic or the laboratory. Cramped workspaces and the heavy protective gear and lead aprons worn by doctors, medical physicists, and support personnel can lead to orthopedic problems, according to the Multi-Specialty Occupational Health Group. Lynne Fairobent of the American Association of Medical Physicists will be discussing data from the Multi-Specialty Occupational Health Group detailing the magnitude of these health concerns.

For more information: www.aapm.org