CCI: Rad exposure for pregnant interventionalists carries low risk
Radiation exposure in the cath lab is very low and along with prudent attention to radiation protection and reduction, the concern should not keep women from choosing a career in interventional cardiology, according to a consensus document published online Nov. 8 in Catheterization and Cardiovascular Interventions.
Patricia J.M. Best, MD, of the Mayo Clinic in Rochester, Minn., and colleagues of the Women in Innovations group of Cardiologists, with endorsement from the Society for Cardiovascular Angiography and Interventions (SCAI), assessed the risk of radiation exposure for pregnant physicians and cardiac cath personnel and outlined proper protocols that can help reduce radiation exposure.
“Concerns regarding radiation exposure and its effects during pregnancy are often quoted as an important barrier preventing many women from pursuing a career in interventional cardiology,” the document stated. “Finding the true risk of radiation exposure from performing cardiac catheterization procedures can be challenging and guidelines for pregnancy exposure have been inadequate.”
While current data do not suggest an increased risk to the fetus in the cath lab, the authors wrote that “radiation exposure among pregnant physicians should be properly monitored and adequate radiation safety measures are still warranted.”
PCI procedures have gotten more complex, such as peripheral vascular interventions, which may be a culprit in increasing operator radiation exposure due to its longer procedural times and greater challenges with shielding the operator. Increased occupational radiation exposure can increase the risk of malignancies and other health hazards for cath lab staff.
Women may be at an even greater risk, particularly during child bearing years—this has increasingly been listed as one of the top reasons for avoiding a career in cardiology. In fact, only 18 percent of all cardiology fellows are women and only 8.7 percent in interventional cardiology fellowship are women.
The document stated that radiation exposure could lead to deterministic effects— intra-uterine growth retardation, pregnancy loss, mental retardation—or stochastic effects—childhood risk of cancer and hereditary diseases in descendants.
"The National Council on Radiation Protection and Measurements (NCRP) recommends limiting occupational radiation exposure of the fetus to a value as low as is reasonably achievable (ALARA) but not to exceed 5 mSv (500 mrem) during the entire pregnancy and 0.5 mSv per month of the pregnancy,” the documents stated. “The risk of induced miscarriages, malignancies, or major congenital malformations in embryos or fetuses exposed to doses of <50 mGy is negligible compared with the spontaneous risk in those without radiation exposure.”
SCAI recommended that following actions to help reduce radiation exposure:
“For a woman to make an informed decision regarding her choices for occupational radiation exposure during pregnancy, she must have a clear understanding of the risk to the fetus,” the authors wrote. “The fetal radiation exposure for most women who work in the cardiac catheterization laboratory is extremely low, and is far lower than limits recommended by the National Council on Radiation Protection.”
Wearing under-lead radiation badges to determine radiation exposure allows a woman to understand her own exposure before making the decision to get pregnant. Additional equipment such as lead aprons, radiation shielding in addition to increasing the distance from the radiation source can help reduce exposure.
"Thus, based on the available evidence, heritable or developmental risks to the fetus of pregnant interventional cardiology physicians and staff are extremely low provided that good radiation safety practices are used and dose limits are respected,” the authors concluded. “Therefore, concerns over radiation exposure should not be a barrier to choice in pursuing a career in invasive or interventional cardiology, nor should they arbitrarily limit an existing operator’s choices on work environments during pregnancy.”
Patricia J.M. Best, MD, of the Mayo Clinic in Rochester, Minn., and colleagues of the Women in Innovations group of Cardiologists, with endorsement from the Society for Cardiovascular Angiography and Interventions (SCAI), assessed the risk of radiation exposure for pregnant physicians and cardiac cath personnel and outlined proper protocols that can help reduce radiation exposure.
“Concerns regarding radiation exposure and its effects during pregnancy are often quoted as an important barrier preventing many women from pursuing a career in interventional cardiology,” the document stated. “Finding the true risk of radiation exposure from performing cardiac catheterization procedures can be challenging and guidelines for pregnancy exposure have been inadequate.”
While current data do not suggest an increased risk to the fetus in the cath lab, the authors wrote that “radiation exposure among pregnant physicians should be properly monitored and adequate radiation safety measures are still warranted.”
PCI procedures have gotten more complex, such as peripheral vascular interventions, which may be a culprit in increasing operator radiation exposure due to its longer procedural times and greater challenges with shielding the operator. Increased occupational radiation exposure can increase the risk of malignancies and other health hazards for cath lab staff.
Women may be at an even greater risk, particularly during child bearing years—this has increasingly been listed as one of the top reasons for avoiding a career in cardiology. In fact, only 18 percent of all cardiology fellows are women and only 8.7 percent in interventional cardiology fellowship are women.
The document stated that radiation exposure could lead to deterministic effects— intra-uterine growth retardation, pregnancy loss, mental retardation—or stochastic effects—childhood risk of cancer and hereditary diseases in descendants.
"The National Council on Radiation Protection and Measurements (NCRP) recommends limiting occupational radiation exposure of the fetus to a value as low as is reasonably achievable (ALARA) but not to exceed 5 mSv (500 mrem) during the entire pregnancy and 0.5 mSv per month of the pregnancy,” the documents stated. “The risk of induced miscarriages, malignancies, or major congenital malformations in embryos or fetuses exposed to doses of <50 mGy is negligible compared with the spontaneous risk in those without radiation exposure.”
SCAI recommended that following actions to help reduce radiation exposure:
- The optimal use of radiation safety techniques should be used in all cases regardless of the operator’s pregnancy status. The key protection factors are under the control of the operator using the imaging equipment. The use of these techniques along with optimized lead shields and personal protective equipment can reduce the radiation exposure to 0.8 percent of unprotected levels. This includes lead shields, which can reduce radiation exposure by 50 to 75 percent;
- Maintaining working views which are posteroanterior (PA) and right anterior oblique (RAO) are preferred to the left anterior oblique (LAO) views as they reduce radiation exposure to the operator standing on the right side of the table;
- Increasing the distance of the operator from the x-ray source is important due to the inverse square relationship of dose and distance. Increasing the working distance from 40 cm to 80 cm can decrease scattered radiation to one-fourth the original dose;
- Frame rate reduction can significantly impact radiation exposure resulting in a reduction of 40 to 60 percent of occupational exposure; and
- Choosing the right equipment—robotic assisted interventions or lead or lead-equivalent protective garments—can dramatically reduce operator radiation exposure.
“For a woman to make an informed decision regarding her choices for occupational radiation exposure during pregnancy, she must have a clear understanding of the risk to the fetus,” the authors wrote. “The fetal radiation exposure for most women who work in the cardiac catheterization laboratory is extremely low, and is far lower than limits recommended by the National Council on Radiation Protection.”
Wearing under-lead radiation badges to determine radiation exposure allows a woman to understand her own exposure before making the decision to get pregnant. Additional equipment such as lead aprons, radiation shielding in addition to increasing the distance from the radiation source can help reduce exposure.
"Thus, based on the available evidence, heritable or developmental risks to the fetus of pregnant interventional cardiology physicians and staff are extremely low provided that good radiation safety practices are used and dose limits are respected,” the authors concluded. “Therefore, concerns over radiation exposure should not be a barrier to choice in pursuing a career in invasive or interventional cardiology, nor should they arbitrarily limit an existing operator’s choices on work environments during pregnancy.”