A novel system designed to reduce radiation exposure to operators during cardiac catheterizations resulted in exposure levels barely above zero, according to a first-in-man report published July 1 in Catheterization and Cardiovascular Interventions. The technology may help raise safety standards, editorialists proposed.
Peter Fattal, MD, of the Michigan Cardiovascular Institute in Covenant Hospital in Saginaw, Mich., and James A. Goldstein, MD, of Beaumont Health System in Royal Oak, Mich., measured radiation exposure to operators using the Trinity Radiation Protection System compared with standard shielding in 19 consecutive, nonrandomized catheterization cases. The system, which combines fixed upper and lower shields, interconnecting radiation drapes, interlocking patient drapes and sterile drapes, was developed by Goldstein and is licensed to a manufacturer.
The increasing use of fluoroscopy in interventional procedures has raised concerns among physicians and staff, who worry about potential adverse events associated with accumulated radiation exposure. Those include not only cancers and cataracts but also orthopedic complications that arise from wearing protective lead aprons. The Trinity system is designed to serve as a barrier to radiation for operators and other staff who work within its protective “umbrella.” It is supposed to eliminate the need for lead aprons while allowing unimpeded access to the patient and equipment.
To test the system’s effectiveness, the researchers compared measurements of radiation exposure in operators in 10 cases performed with the Trinity system in place and nine cases with only standard shielding. The cases were both diagnostic and therapeutic. In all cases, operators wore standard leaded protective apparel with dosimeters on the outside of aprons at the head, neck, waist and chest. Fattal and Goldstein recorded fluoroscopy times and calculated radiation exposure to the operator for each case and anatomic area.
It took about 10 extra minutes to set up the Trinity system, they reported. The system did not interfere with access to the patient or equipment and there were not technical difficulties. Radiation protection under the Trinity system reached 99 percent. The total normalized radiation exposure with the standard lead apron approach was about 0.11 mSv per minute of fluoroscopy time.
“Presently, physicians using this device are routinely performing procedures without wearing leaded apparel,” Fattal and Goldstein wrote. “Using this radiation protection equipment has potential to reduce operator occupational health risks associated with working in the fluoroscopy laboratory.”
Preetham Kumar, MD, and Michael S. Levy, MD, MPH, of the cardiovascular division at the Mayo Clinic in Rochester, Minn., commented in an editorial that the results are not generalizable, but showed that the technology was practical and met safety standards. They and the Michigan researchers described other innovations to minimize radiation and orthopedic risks as a sign that it may be time to raise the bar on current standards.
“[P]erhaps the new goal in radiation safety should not be the ALARA (as low as reasonably achievable) model, which is a nebulous goal, but rather a goal toward ‘no dose’ exposure should be the new standard,” Kumar and Levy wrote.
Fattal and Goldstein listed several limitations, including lack of assessment of radiation exposure to staff. The system does not accommodate the radial access approach to catheterization but a redesign is in progress.