A Retrospective, Single-Center Study of Technical-Procedural Factors Affecting Radiation Dose During Prostatic Artery Embolization

Abstract

Introduction This study aims to evaluate the effect of technical-procedural factors on radiation dose during prostatic artery embolization (PAE). Methods This was a single-center, retrospective study of 59 patients with benign prostatic hyperplasia (BPH) who underwent prostatic artery embolization from March 2020 to September 2021. Computed tomography angiography (CTA) was performed for vascular planning prior to PAE in all patients. The effect of the following techniques on the dose area product (DAP) of PAE was evaluated: application of low-dose protocol (LDP) for digital subtraction angiography (DSA), reduction of oblique projections by performing PAE of at least one pelvic side utilizing anteroposterior projections only (AP-PAE), utilization of "roadmap" technique instead of DSA for the delineation of pelvic arterial anatomy (RDMP-PAE), and cone-beam CT (CBCT). The impact of the patient's body mass index (BMI) on DAP was also calculated. The effective dose (ED) of PAE and pre-PAE CTA was calculated from DAP and from dose length products, respectively, using appropriate conversion factors. Results For the entire study population (n = 59), the mean DAP of PAE was 16,424.7 ± 8,019 μGy‧m². On simple regression analysis, LDP, AP-PAE, and RDMP-PAE significantly contributed to DAP reduction during PAE (30% (p = 0.004), 26.7% (p = 0.013), and 31.2% (p = 0.004), respectively). On multiple regression, LDP and AP-PAE maintained their significant effect (p = 0.002 and p = 0.006, respectively). CBCT was associated with a not statistically significant increase in DAP (10.1%) (p = 0.555). The ED of CTA represented 21.2% ± 10.6% of the ED of PAE. Conclusion Of the four studied factors, LDP, AP-PAE, and RDMP-PAE proved to be relatively simple and widely available techniques that could limit radiation exposure of both the operators and the patients during PAE. The contribution of planning CTA to the overall radiation exposure of patients undergoing PAE appears to be not negligible.

Keywords: computed tomography angiography; cone-beam computed tomography; digital subtraction angiography; dose area product; prostatic artery embolization; radiation dose; roadmap.

Figure 1. Digital subtraction angiography (DSA) images (A,B) acquired with similar tube angulation and no magnification from two patients in the study show the pelvic arterial anatomy relevant to PAE. The standard DSA protocol (“Body”) was applied in (A), and the low-dose DSA protocol (“Body CARE”) was applied in (B). Prostatic arteries (arrows in both images) can be easily identified in both images; however, the application of low-dose DSA protocol was associated with a significantly lower dose area product (DAP) (64.4 μGy‧ m2/frame versus 152 μGy‧m2/frame), despite the much higher body mass index (BMI) of the patient of image B (38 versus 27).

Figure 2. Kaplan-Meier curves showing the clinical success rates of the two main subgroups of the study.

Red line: the subgroup with the application of LDP, with or without other techniques; blue line: the rest of the patients Differences were not statistically significant (p = 0.514). LDP: low-dose protocol