C-arm computed tomography parenchymal blood volume measurement in evaluation of hepatocellular carcinoma before transarterial chemoembolization with drug eluting beads

Background: C-arm computed tomography (CT) guided intervention is an increasingly applied technique in transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). The aim of this study was to analyse the value of parenchymal blood volume (PBV) maps acquired during C-arm CT acquisition, for pre-treatment evaluation and planning of TACE in HCC patients. Methods: A total of 64 HCC lesions in 29 patients (median age, 73 years, range, 62-77 years) were included in this retrospective study. All patients received cross-sectional imaging (MRI or CT) prior to TACE and C-arm CT PBV measurement acquisition before performing TACE. Results of cross-sectional imaging regarding the number of HCC lesions and maximum diameter were compared to PBV-maps. Number of lesions and tumour feeding vessels detected in PBV-maps were compared to conventional angiography. Results of PBV were analysed concerning different tumour morphologies (pre-treated, encapsulated and diffuse). Results: Pre-interventional cross-sectional imaging and PBV maps showed an excellent agreement in lesion diameter (p = 0.88, MD = -0.28 mm) and number of detected lesions (kappa = 1.0). Compared to conventional angiography, PBV maps showed an increased number of detected lesions (kappa = 0.77, p = 0.001) and tumour feeding vessels (kappa = 0.71, p < 0.0001). Diffuse HCC lesion revealed a significantly lower PBV compared to encapsulated lesions (p = 0.0001). Conclusions: C-arm CT acquired PBV measurements detect HCC tumours with a lesion detectability comparable to pre-interventional cross-sectional imaging. Furthermore, this technique facilitates TACE, allowing a more precise localization of HCC lesions and tumour feeding vessels compared to conventional angiography. Additionally, calculated PBV values enable a real time quantitative assessment of tumour perfusion.