Prostatic artery embolization performed in anteroposterior projections versus steep oblique projections: single centre retrospective comparative analysis

PAE planning: Radiation exposure and image quality of CT and CBCT

PURPOSE

To determine accurate organ doses, effective doses, and image quality of computed tomography (CT) compared with cone beam CT (CBCT) for correct identification of prostatic arteries.

METHOD

A dual-energy CT scanner and a flat-panel angiography system were used. Dose measurements (gallbladder (g), intestine (i), bladder (b), prostate (p), testes (t), active bone marrow of pelvis (bmp) and femura (bmf)) were performed using an anthropomorphic phantom with 65 thermoluminescent dosimeters in the pelvis and abdomen region. For the calculation of the contrast-to-noise ratio (CNR) of the pelvic arteries, a patient whose weight and height were almost identical to those of the phantom was selected for each examination type.

RESULTS

The effective dose of CT was 2.7 mSv and that of CBCT was 21.8 mSv. Phantom organ doses were lower for CT than for CBCT in all organs except the testes (g: 1.2 mGy vs. 3.3 mGy, i: 5.8 mGy vs. 23.9 mGy, b: 6.9 mGy vs. 19.4 mGy, p: 6.4 mGy vs. 13.2 mGy, t: 4.7 mGy vs. 2.4 mGy, bmp: 5.1 mGy vs. 18.2 mGy, bmf: 3.3 mGy vs. 6.6 mGy). For human pelvic arteries, the CNR of CT was better than that of CBCT, with the exception of one prostate artery that showed stenosis on CT. Evaluation by experienced radiologists also confirmed the better detectability of prostate arteries on CT examination.

CONCLUSIONS

In our study preprocedural CT had lower organ doses and better image quality comparedd with CBCT and should be considered for the correct identification of prostatic arteries.

Angiographic Imaging of Prostatic Artery Origin in a Greek Population and Correlation With Technical and Clinical Aspects of Prostatic Artery Embolization

Background This study aimed, first, to angiographically investigate and analyze prostatic artery (PA) origin in a Greek male population with benign prostatic hyperplasia (BPH) treated with prostatic artery embolization (PAE) and, second, to correlate prostatic arterial anatomy with technical and clinical aspects of PAE. Methodology This was a retrospective study of BPH patients who underwent PAE in a single tertiary center in Greece from June 2019 to July 2022. For the first part of the study, PA was imaged with computed tomography angiography (CTA) before PAE and with digital subtraction angiography (DSA) during PAE in all patients. A widely accepted system for the classification of PA origin was applied. Type I, a common origin of PA and superior vesical artery (SVA) from the anterior division of internal iliac artery (IIA). Type II, PA originating from the anterior division of IIA, separate from, and inferior to SVA. Type III, the origin of PA from the obturator artery. Type IV, the origin of PA from the internal pudendal artery. Type V, rarer origins of PA. For the second part of the study, a subgroup of patients from the first part (treated with the same PAE protocol and free of vascular pathology that could have interfered with the technical success of PAE) was selected. In this subgroup, differences in PA origin were correlated with technical aspects (feasibility of catheterization of PA, fluoroscopy time (FT), dose area product (DAP)) and clinical outcomes of PAE. Results After the exclusion of four patients, 159 patients were included in the first part of the study. From a total of 355 PAs, 110 (31%) were compatible with type I, 58 (16.3%) type II, 45 (12.7%) type III, 110 (31%) type IV, and 32 (9%) type V. PA origin from an accessory internal pudendal artery was the most common among the rare origins of type V. Regarding the second part of the study (a subgroup of 101 patients selected to facilitate comparisons between the different types of PA origin), type I was associated with significantly more incidences of failed or difficult catheterization of the PA compared to all other types combined (27/64 vs. 18/138, p < 0.001). Types III, IV, and V showed a relatively low degree of technical difficulty. Patients with type I PA origin of at least one pelvic side (subgroup (I), n = 48) had significantly longer FT and DAP compared to the rest (subgroup (O), n = 53). Clinical success rates of PAE were slightly lower for the subgroup (I), although the difference was not statistically significant (75.8% vs. 83.8% at 18 months post-PAE, p = 0.137). No major complications were observed. Conclusions This is the first study of PA origin in Greece. It was demonstrated that types I and IV of PA origin were the most common and had the same prevalence. Type I showed significantly higher technical difficulty compared to the others, but had no significant impact on the clinical outcomes of PAE.

Center experience and other determinants of patient radiation exposure during prostatic artery embolization: a retrospective study in three Scandinavian centers

OBJECTIVES

To evaluate the effects of center experience and a variety of patient- and procedure-related factors on patient radiation exposure during prostatic artery embolization (PAE) in three Scandinavian centers with different PAE protocols and levels of experience. Understanding factors that influence radiation exposure is crucial in effective patient selection and procedural planning.

METHODS

Data were collected retrospectively for 352 consecutive PAE procedures from January 2015 to June 2020 at the three centers. Dose area product (DAP (Gy·cm²)) was selected as the primary outcome measure of radiation exposure. Multiple patient- and procedure-related explanatory variables were collected and correlated with the outcome variable. A multiple linear regression model was built to determine significant predictors of increased or decreased radiation exposure as reflected by DAP.

RESULTS

There was considerable variation in DAP between the centers. Intended unilateral PAE (p = 0.03) and each 10 additional patients treated (p = 0.02) were significant predictors of decreased DAP. Conversely, increased patient body mass index (BMI, p < 0.001), fluoroscopy time (p < 0.001), and number of digital subtraction angiography (DSA) acquisitions (p < 0.001) were significant predictors of increased DAP.

CONCLUSIONS

To minimize patient radiation exposure during PAE radiologists may, in collaboration with clinicians, consider unilateral embolization, pre-interventional CTA for procedure planning, using predominantly anteroposterior (AP) projections, and limiting the use of cone-beam CT (CBCT) and fluoroscopy.

KEY POINTS

• Growing center experience and intended unilateral embolization decrease patient radiation exposure during prostatic artery embolization. • Patient BMI, fluoroscopy time, and number of DSA acquisitions are associated with increased DAP during procedures. • Large variation in radiation exposure between the centers may reflect the use of CTA before and CBCT during the procedure.