Foetal Radiation Dose During Prophylactic Occlusion Balloon Placement for Morbidly Adherent Placenta.

OBJECTIVE

To assess foetal absorbed radiation dose (FAD) during prophylactic occlusion balloon catheter (POBC) placement before surgery for morbidly adherent placenta (MAP).

METHODS

Retrospective cohort study of women with MAP undergoing POBC before surgery. Women were divided into two groups. Group 1 treated between 2008 and 2011, Group 2 between 2012 and 2014 when fluoroscopy pulse rate reduced from 7.5 to 2 pulses per second. Median and interquartile range (IQR) of dose area product (DAP) and FAD were compared using the Mann-U-Whitney test. FAD was calculated using the PCXMC Monte-Carlo calculation. All procedures were performed using the same equipment (Siemens Axiom Artis dTA) by the same experienced interventional radiology team.

RESULTS

Thirty-four women underwent POBC. 16 procedures were performed in Group 1 and 18 in Group 2. Median DAP overall was 1025.10 µGym(2) (IQR 532.1-1775.3): Group 1, 1713.25 µGym(2) (IQR 1164.5-2274.5) and Group 2, 660.70 µGym(2) (IQR 440.9-1020.9) (p = 0.027). Median FAD overall was 4.65 mGy (IQR 2.7-8.2): Group 1, 6.25 mGy (IQR 4.4-10.6) and Group 2, 3.05 mGy (IQR 2.0-5.4) (p = 0.031).

CONCLUSIONS

FAD during POBC insertion is low overall. The only change between the two groups was in pulsed fluoroscopy rate which resulted in a significant reduction in FAD. This reinforces the importance of implementation of dose reduction techniques.