Occupational radiation exposure in interventional cardiology - time for further action

A dual-centre study on the radioprotective effect of a novel X-ray protection device during coronary intervention

AIM

To investigate the shielding efficiency of a novel X-ray protection device (NPD) compared with the traditional lead clothing (TLC) during coronary intervention.

MATERIALS AND METHODS

This study was performed prospectively in two centres. A total of 200 coronary interventions were included and assigned equally into the NPD or TLC group. The NPD is a floor-standing X-ray protection device, which mainly composes of a barrel-like frame and two layers of lead rubber. Thermoluminescent dosimeters (TLDs) were adopted to detect the cumulative absorbed doses, and were attached outside the NPD or TLC or body of the first operator at four different height levels in four directions during the procedure.

RESULTS

The cumulative doses outside the NPD were comparable to that of the TLC (2,398.33 ± 2,341.64 versus 1,624.09 ± 1,732.20 μSv, p=0.366), and the cumulative doses inside the NPD were significantly lower than those inside the TLC (40 ± 0 versus 732.28 ± 919.83 μSv, p<0.001). As the TLC did not cover the calf segment of the operator, the area at 50 cm height from the floor in the TLC group was unshielded. The shielding efficiency of NPD was significantly higher than that of the TLC (98.2 ± 0.63% versus 52.11 ± 38.97%, p=0.021).

CONCLUSION

The NPD has a significantly higher shielding efficacy than that of the TLC, in particular, it protects the operators' lower limb, liberates their lower body from wearing heavy lead apron, and may consequently reduce the radiation or body-load associated complications.

Anthropometric parameters and radiation doses during percutaneous coronary procedures

PURPOSE

Body size is a major determinant of patient's dose during percutaneous coronary interventions (PCI). Body mass index, body surface area (BSA), lean body mass and weight are commonly used estimates for body size. We aim to identify which of these measures and which procedural/clinical characteristics can better predict received dose.

METHODS

Dose area product (DAP, Gycm²), fluoroscopy DAP rate (Gycm²/min), fluoroscopy DAP (Gycm²), cine-angiography DAP (Gycm²), Air Kerma (mGy) were selected as indices of patient radiation dose. Different clinical/procedural variables were analysed in multiple linear regression models with previously mentioned patient radiation dose parameters as end points. The best model for each of them was identified.

RESULTS

Overall 6623 PCI were analysed, median fluoroscopy DAP rate was 35 [IQR 2.7,4.4] Gycm², median total DAP was 62.7 [IQR 38.1,107] Gycm². Among all anthropometric variables, BSA showed the best correlation with all radiation dose parameters considered. Every 1 m² increment in BSA added 4.861 Gycm²/min (95% CI [4.656, 5.067]) to fluoroscopy DAP rate and 164 Gycm² (95% CI [145.3, 182.8]) to total DAP. Height and female sex were significantly associated to a reduction in fluoroscopy DAP rate and total DAP. Coronary angioplasty, diabetes, basal creatinine and the number of treated vessels were associated to higher values.

CONCLUSIONS

Main determinants of patient radiation dose are: BSA, female sex, height and number of treated vessels. In an era of increasing PCI complexity and obesity prevalence, these results can help clinicians tailoring X-ray administration to patient's size.