Left, center of head most affected by radiation exposure during interventional procedures
During invasive CV procedures, interventional cardiologists are exposed to significantly more radiation on the left and center of the cranium than the right side, according to new data from the BRAIN study.
However, when researchers examined the protective ability of a lightweight, nonlead, layered cap, they found that it reduced radiation exposure across the head.
The single-center, prospective study included seven cardiology fellows and four attending physicians who performed fluoroscopy-guided, invasive CV procedures at an academic medical center. All participants were men and the mean age was 38 years. On average, each interventional cardiologist performed 66 cases per operator (mean fluoroscopy time, 15 minutes).
Each operator for an XPF attenuating cap (BLOXR Corp.), which featured six dosimeters (InLight nanoDot, Landauer Inc.) placed in small pockets on the outer and inner surfaces at locations that corresponded to the center, left and right sides of the head. The cap is made of flexible strips of bi-layered barium sulfate and bismuth oxide, which is configured into a semidisposable, lightweight cloth design. These materials have been demonstrated to significantly reduce radiation, providing the equivalent of a 0.5-mm thick lead barrier, according to background information in the study. Operators used the same cap during the study period and then the dosimeters were analyzed for radiation exposure. Additionally, three dosimeters were located outside of the catheterization lab for measurement of ambient radiation exposure.
According to the results, radiation exposure was higher at dosimeters placed at the outside left (mean exposure, 106.1 ± 33.6 mrad) and outside center (83.1 ± 18.9 mrad) of the head vs. the outside right of the head (50.2 ± 16.2 mrad; P < .001 for comparisons).
Use of the XPF cap mitigated radiation exposure at the inside left location of the head (mean exposure, 42.3 ± 3.5 mrad), inside center (42 ± 3 mrad) and insight right (41.8 ± 2.9 mrad). The attenuation of radiation exposure with the cap was slightly higher than that observed with the ambient control (38.3 ± 1.2 mrad; P = .046).
When the researchers subtracted ambient radiation, they found that exposure on the outside left section of the head was 16 times higher than at the inside left and 4.7 times higher than at the outside right (P < .001 for both). The outside center section of the head was exposed to 11 times more radiation compared with the insight center (P < .001). The researchers observed no difference on the right side of the head.
According to the researchers, additional research is needed to determine strategies to further attenuate radiation exposure to operators who perform invasive CV procedures.
“The recent reports of left-sided brain cancer in operators of fluoroscopically guided procedures are alarming given the location and aggressive nature of these malignancies. Invasive cardiologists are exposed to some of the highest levels of radiation in the medical field and constitute the majority of subjects in the reported cases,” the researchers wrote.
They concluded that a protective cap like the one studied “has the potential to reduce exposure across the head to nearly ambient levels.” – by Jennifer Byrne
Disclosure: BLOXR Corp. provided the caps for the study, but did not participate in the writing of the protocol or data analysis. One researcher reports serving on the speakers’ bureau of AstraZeneca; another researcher reports clinical trial support from Boston Scientific, Corindus and Gilead, consulting for The Medicines Company and serving on the speakers’ bureau of Medtronic. The other researchers report no relevant financial disclosures.