Pediatric cardiac catheterization could be performed with low levels of radiation exposure using one center’s “as low as reasonably achievable” (ALARA) protocol, researchers reported.
The strategy employed by Lisa Goto, MD, and colleagues at the Children’s Hospital at Montefiore in New York City, resulted in favorable radiation levels across 95 catheterizations in 77 children weighing 20-40 kg (approximately 44-88 lbs):
- Median fluoroscopy time: 11.9 minutes
- Total air Kerma product: 38 mGy
- Dose air product (DAP): 175 µGym2
- DAP by weight: 7 µGym2/kg
Based on these findings, radiation exposure during cardiac catheterization with ALARA seems to compare favorably against published values, as Goto cited prior reports of air Kerma reaching 370-400 mGy and DAPs exceeding 2,000 µGym2 in similar patients. She presented her group’s abstract at the virtual meeting of the Society for Cardiovascular Angiography and Interventions (SCAI).
“Given the epidemiological evidence we already have that strongly suggests an increased cancer risk from medical ionizing radiation exposure to children, such findings are potentially important,” commented Andrew Einstein, MD, PhD, of Columbia University Irving Medical Center in New York City.
“However, while these findings are encouraging in terms of the low radiation doses, minor complications were noted in the small sample and the study was not randomized and in fact did not even include a historical control group,” he warned.
Goto asserted that ALARA did not change image quality and complication rates from standard of care. However, she did report three minor complications that were self-limited: one accelerated junctional rhythm, two broken balloons with stent placement, and one hemoptysis.
The study included children (median age 9 years, median weight 60.6 lbs) who underwent cardiac catheterization at Goto’s center in 2015-2020. Excluded were transplant patients who had routine endomyocardial biopsy or biopsy with coronary angiography.
Interventions most frequently performed in these patients were atrial septal defect device closure, pulmonary artery dilation, and patent ductus arteriosus closure.
The investigators used the ALARA protocol consisting of ultra-low frame rates (2-3 frames per second) and low fluoroscopy dose (10-18 nGy/frame), plus the air gap technique (i.e., removal of anti-scatter grid, with the flat panel detector placed 110 cm from the patient).
“ALARA is especially important in pediatrics, where patients are more radiosensitive with higher rates of mitosis compared to adults,” Goto said, emphasizing that children tend to be smaller and have longer life expectancies. Patients with congenital heart disease in particular may stand to benefit, as they undergo multiple catheterizations and have an increased lifetime risk of radiation exposure per year, she added.
“While Goto and Sutton’s study demonstrates promise for the air gap technique, this technique cannot yet be regarded as definitive but rather warrants further investigation,” Einstein concluded.