Optimizing the Angiography Protocol to Reduce Radiation Dose in Uterine Artery Embolization: The Impact of Digital Subtraction Angiographies on Radiation Exposure.

PURPOSE: The aim was to compare a protocol of uterine artery embolization (UAE) consisting in three digital subtraction angiographies (DSAs)-Group A, with a protocol based on a single DSA-Group B. MATERIALS AND METHODS: This is a single-center prospective randomized study enrolling 20 women (mean age 41 years, range 22-55 years) with uterine fibroids treated with UAE, from January 2015 to February 2016. All UAEs were performed by two interventional radiologists using the same angiography machine. Protocol of Group A consisted in three DSA runs (non-selective pelvic view and selective uterine views before and after embolization). Protocol of Group B consisted in 1 DSA run: selective UA angiography before embolization. (Fluoroscopic roadmap was used for UA catheterization; fluoroscopy storage was used as control after embolization.) Each patient was randomized to receive Protocol A in one pelvic side and Protocol B on the other. RESULTS: All patients received bilateral UAE. Mean fluoroscopy time for UA catheterization was 11.3 ± 3.7 s. (Protocol A) and 9.93 ± 2.99 s. (Protocol B) (p = 0.19). Fluoroscopy dose for catheterization and embolization was not different between both protocols (p = 0.14). Identification of the UA origin score was similar in both protocols (median error = 0, p = 0.79). Mean dose area product (DAP) was 40859 mGy/cm2 (Protocol A) and 28839 mGy/cm2 (Protocol B) (p = 0.003). Mean effective dose (ED) decreased from Protocol A (14.6 mSv) to Protocol B (9.2 mSv; - 37%). Mean absorbed dose (AD) to ovaries and uterus, respectively, decreased of 53% and 55% from Protocol A to Protocol B. CONCLUSION: Reducing the number of DSA runs from 3 to 1 during UAE allows at least a 30% reduction on radiation exposure, without compromising technical outcomes.

Radiation exposure of the operators in the preparation and administration of yttrium-90 microspheres in the treatment of malignant hepatic lesions: What is the risk?

Liver radioembolization is an emerging treatment against liver primary and secondary tumours. The whole procedure of radioembolization involves different health care specialists with different expertise. During the fractionation and infusion phases, the personnel manipulates high activities of 90Y. In our centre, the number of radioembolization treatments per year is increasing; the aim of this study is to monitor the dose to the operators and to estimate the radiological risk for the operators involved in the RE. At present, two medical devices are approved: Sir-Sphere® and Therasphere™, both loaded with 90Y. The dosimeters used were TLDs placed over the fingertips, for a total of 4 dosimeters for each phase; the selected dose descriptor was Hp0.07. The study concerned 17 patients affected by malignant hepatic lesions, treated from September 2017 to March 2018. We performed 27 procedures: 10 fractionations (with Sir-Sphere®) and 17 infusions to the patients (10 with Sir-Spheres®, 7 with Theraspheres™). For fractionation phase, the average activity of each preparation was 3.34 GBq, the average value of Hp0.07 was 0.50mSv. For infusion phase, the average activity was 1.51 GBq for Sir-Sphere® and 2.10 GBq for Theraspheres™, the average value of Hp0.07 was 0.10mSv. No significant differences were found between senior (Hp0.07 = 0.08mSv) and young operators (Hp0.07 = 0.09mSv), respectively. Similarly, no significant differences were found between the right and left hand, with the same average value of Hp0.07 (0.01mSv). In conclusion, the results are encouraging, since fingertips reported doses very low. The handling of 90Y microspheres and the radioembolization procedure can be carried out under safe conditions.

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.