Radiation exposure during angiographic interventions in interventional radiology - risk and fate of advanced procedures

Comparison of Radial Versus Femoral Access for Neuroendovascular Procedures in Very High Body Mass Index Individuals

BACKGROUND

Femoral access (TFA) for neuroendovascular procedures may present a challenge in very high body mass index (BMI) individuals. Whether radial access (TRA) confers a comparative benefit in this specific population has not been studied.

METHODS

We retrospectively identified all patients undergoing neuroendovascular procedures at our center between 2017 and 2021 with BMI ≥35 kg/m2. A total of 335 patients met our inclusion criteria, with 224 undergoing femoral access and 111 undergoing radial access. Electronic medical records were reviewed for baseline clinical and angiographic characteristics and procedural outcomes.

RESULTS

The primary outcome of any bleeding complication occurred in 7% of the femoral group and 2% of the radial group (odds ratio 4.2, 95% confidence interval 1.0-18.6, P = 0.0421). Radial access was also associated with significantly shorter mean procedure times (median 43 minutes for radial, median 58 minutes for femoral, P = 0.0009) and mean fluoroscopy exposure times (median 15 minutes for radial, median 20 minutes for femoral, P = 0.0003). There were no significant differences in nonaccess site complications, procedural failure, length of stay, or deaths during hospitalization.

CONCLUSIONS

When compared to TRA, TFA was associated with a significantly greater rate of bleeding complications in very high BMI patients undergoing neuroendovascular procedures. Procedure time and fluoroscopy time were both significantly longer when using TFA compared to TRA in this patient population.

Analysis of Periprocedural X-ray Exposure in Transarterial Radioembolization with Glass or Resin Microspheres

Background: Transarterial Radioembolization (TARE) is an effective treatment option for both primary and secondary liver malignancies. However, challenging anatomical conditions can lead to prolonged fluoroscopy times (FT), elevated doses of periprocedural X-radiation (DAP), and increased use of contrast agents (CAs). In this study, we examined the influence of our radiologists' experience and the choice of microspheres on X-ray exposure and CA doses in TARE. Material and Methods: Datasets comprising 161 TARE and 164 preprocedural evaluation angiographies (TARE-EVA) were analyzed. Our study focused on assessing DAP, FT, and CA concerning both microsphere types, the radiologist's experience, and whether the same radiologist performed both the TARE-EVA and the actual TARE. Results: In TARE, the use of resin microspheres resulted in significantly higher FT and CA compared to glass microspheres (14.3 ± 1.6 min vs. 10.6 ± 1.1 min and 43 ± 2.2 mL vs. 33.6 ± 2.1 mL, p < 0.05), with no notable differences in DAP (p = 0.13). Experienced radiologists demonstrated reduced FT/DAP, with a 19% decrease in DAP and 53% in FT during the evaluation angiography (p < 0.05) and a 49% reduction in DAP during the actual TARE (p < 0.05), with no statistical differences in FT. Performing TARE and TARE-EVA under the same radiologist led to a 43% reduction in DAP and a 25% decrease in FT (p < 0.05, respectively). Conclusions: To mitigate X-radiation exposure, it is advisable for radiologists to undergo thorough training, and, ideally, the same radiologist should conduct both the TARE and the TARE-EVA. While the use of glass spheres may decrease intraarterial CA, it does not significantly impact periprocedural X-ray exposure.

Operator radiation exposure during radioembolisation of the liver: transfemoral versus transradial access using real-time dose monitoring

In this study, operator radiation exposure is compared utilising transradial access (TRA) versus transfemoral access (TFA) during transarterial radioembolisation (TARE) of liver tumors. Patients who underwent Y90 TARE between May 2017 and April 2018 were included. Electronic medical records and interventional data were collected and the following parameters evaluated: technical success, fluoroscopy time, operator radiation exposure and rate of operator radiation exposure per fluoroscopy time. Statistical analysis was performed with the Wilcoxon rank-sum test. A total of 22 patients (12 males, 10 females) underwent 22 procedures. A total of 12 procedures were performed via TFA and 10 via TRA. Technical success was 100% in both groups. Median fluoroscopy time (10 minutes for TRA vs 6.4 minutes for TFA, p = 0.082) was not statistically different. Both operator radiation exposure (49 vs 4.2 μSv, p = 0.00016) and rate of operator exposure (4.9 vs 0.71 μSv per min, p = 0.00021) were significantly higher in the TRA versus TFA groups, respectively.

Real-Time MRI Monitoring of Liquid Embolic Agent (Onyx) Injection in a Swine Arteriovenous Malformation Model

The paradigm is gradually shifting, with radiosurgery and endovascular embolization being increasingly chosen over surgical resection in the selected cases of brain arteriovenous malformations. Routinely used X-ray monitoring of liquid embolic infusion has very good spatial and temporal resolution but is not without significant drawbacks regarding poor visualization of the complex AVM angioarchitecture, especially after many embolizations in the past and therefore limiting the technical ability of the embocure-total occlusion of the feeding arteries, nidus, and draining veins. The purpose of this study was to evaluate the use of real-time MRI guidance in endovascular embolization with Onyx (instead of X-ray) in a single swine rete mirabile (RM) AVM model in order to provide the scaffolding for the real-time MRI guidance method. Onyx propagation was observed in real-time dynamic GE-EPI scan with initial ipsilateral RM filling followed by main cerebral arterial branch distribution. The relatively bright signal within RM and the brain prior to Onyx injection provided a good background for the dark, low signal of the embolic agent spreading in rete mirabile and brain arteries. X-ray picture confirmed Onyx cast distribution at the end of the procedure. In this initial experience, real-time MRI seems to be a promising method that may significantly improve liquid embolic agent infusion monitoring in the future, although requiring further development before clinical use.

Occupational radiation exposure of neurointerventionalists during endovascular stroke treatment

BACKGROUND

Radiological neuro-interventions, especially endovascular stroke treatment (EST), are increasing in case numbers worldwide with increasing occupational radiation exposure. Aim of this study was to define the radiation exposure of neurointerventionalists (NI) during EST and to compare the accumulated dose reaching the left arm with the left temple.

METHODS

This is a prospective observational study in a tertiary stroke center conducted between 11/2021 and 07/2022. Radiation exposure was measured using real time dosimetry with dosimeters being carried by the NI during EST simultaneously at the left temple and left arm. The effective dose [µSV] per dose area product (DAP) and potential influencing factors were compared in univariate analysis between the two dosimeter positions.

RESULTS

In total, 82 ESTs were analyzed with a median DAP of 6179 µGy*m² (IQR 3271 µGy*m²-11720 µGy*m²). The accumulated dose at the left arm and left temple correlated with the DAP and fluoroscopy time of the EST (DAP and arm: p = 0.01, DAP and temple: p = 0.006). The radiation exposure (RE) showed a wide range and did not differ between the two dosimeter positions (median, IQR arm 7 µSV, IQR 3.1-16.9 µSV, min. 0.3 µSV max. 64.5 µSV) vs. head 7 µSv, IQR 3.2-17.4 µSV, min. 0.38 µSV, max. 48.6 µSV, p = 0.94). Occupational RE depends on the number of thrombectomy attempts, but not the target vessel occlusion location or the NI's body height.

CONCLUSION

Neurointerventionalists experience a generally low but very variable radiation exposure during EST, which depends on the intervention's fluoroscopy time and dose area product as well as thrombectomy attempts but does not differ between left temple and left arm.

Reduction of radiation dose using real-time visual feedback dosimetry during angiographic interventions

This prospective study sought to evaluate potential savings of radiation dose to medical staff using real-time dosimetry coupled with visual radiation dose feedback during angiographic interventions. For this purpose, we analyzed a total of 214 angiographic examinations that consisted of chemoembolizations and several other types of therapeutic interventions. The Unfors RaySafe i2 dosimeter was worn by the interventionalist at chest height over the lead protection. A total of 110 interventions were performed with real-time radiation dosimetry allowing the interventionalist to react upon higher x-ray exposure and 104 examinations served as the comparative group without real-time radiation monitoring. By using the real-time display during interventions, the overall mean operator radiation dose decreased from 3.67 (IQR, 0.95-23.01) to 2.36 μSv (IQR, 0.52-12.66) (-36%; p = 0.032) at simultaneously reduced operator exposure time by 4.5 min (p = 0.071). Dividing interventions into chemoembolizations and other types of therapeutic interventions, radiation dose decreased from 1.31 (IQR, 0.46-3.62) to 0.95 μSv (IQR, 0.53-3.11) and from 24.39 (IQR, 12.14-63.0) to 10.37 μSv (IQR, 0.85-36.84), respectively, using live-screen dosimetry (p ≤ 0.005). Radiation dose reductions were also observed for the participating assistants, indicating that they could also benefit from real-time visual feedback dosimetry during interventions (-30%; p = 0.039). Integration of real-time dosimetry into clinical processes might be useful in reducing occupational radiation exposure time during angiographic interventions. The real-time visual feedback raised the awareness of interventionalists and their assistants to the potential danger of prolonged radiation exposure leading to the adoption of radiation-sparing practices. Therefore, it might create a safer environment for the medical staff by keeping the applied radiation exposure as low as possible.

Radiation dose aspects and establishment of diagnostic reference levels for90Y radioembolisation during angiographic procedure

⁹⁰Y radioembolisation (RE) is an angiographic procedure used in patients with both primary and secondary hepatic malignancies. Local tumour control can be achieved by short range tumour irradiation by the regional intra-arterial administration of glass or resin microspheres loaded with 90yttrium that accumulate in the tumorous tissue. The aim of this study was to investigate the radiation exposure of RE and to establish a local diagnostic reference level (DRL). In this retrospective study, dose data from 397 procedures in 306 patients (mean age 67.4 ± 10.6 years, 82 female) who underwent RE between 06/2017 and 01/2022 using one of two different angiography systems were analysed. DRL was set as the 75th percentile of the dose distribution. In the overall population, dose area product (DAP) (median (interquartile range, IQR)) was 26 Gy cm²(IQR 12-50) with a median fluoroscopy time (FT) of 4.5 min (IQR 2.9-8.0). FT and DAP increased significantly with the number of infusion positions (median, IQR): one position 23 Gy cm²(12-46), two positions 33 Gy cm²(14-60), three positions 50 Gy cm²(24-82) (p< 0.0001). Local DRL is 47 Gy cm²for RE and 111 Gy cm²for RE with additional embolisation. Radiation exposure and FT are significantly higher with increasing number of infusion positions as well as additional embolisation. Our established DRLs for RE may serve as a benchmark for dose optimisation.