Results of Intraoperative Virtual-assisted Artery Mapping during Transarterial Chemoembolization

Abstract

Transarterial chemoembolization (TACE) is a treatment method for hepatocellular carcinoma (HCC), with indications in various stages of the disease (most commonly reported indication being intermediate stage disease or BCLC stage B). This minimally invasive procedure is classically performed under the guidance of two dimensional (2D) digital subtraction angiography (DSA). However, a more novel option is cone-beam computed tomography (CBCT) which has been increasingly utilized for intraoperative guidance. Furthermore, through the data-set obtained from the CBCT acquisition, automated tumor feeder detection software (AFD) can be applied for further intraprocedural assistance. Considering the immense applicability of TACE along with the ever-increasing availability of intraprocedural CBCT, exploring the underlying mechanisms of CBCT-guided TACE and AFDs, as well as their application in modern management of HCC is warranted. This thesis thus focuses on the technical aspects and utility of CBCT-guided TACE and AFDs. Additionally, a real-life clinical case involving intraprocedural CBCT in tACE is briefly presented in this paper.

An analytical literature review was conducted by obtaining scientific paper from peer-reviewed journals published between 2013-2023. These were accessed via NCBI, PubMed registry, SpringerLink, ScienceDirect, among others.

TACE involves the local administration of chemotherapeutic agents with or without carrier particles. From the reviewed literature, comparing DSA to interoperative CBCT, a high degree of sensitivity regarding depiction of tumors and tumor-feeding arteries has been repeatedly reported. This includes noting extra-hepatic collaterals as well as smaller tumor lesions. Improved clinical efficacy has also been reported, including aiding short-term prediction of response and being an independent factor associated with e.g. increased overall survival.

AFDs involve outlining a region of interest onto CBCT images and establishing placement of catheter tip, followed by an automatic depiction of the arterial feeders with a real-time roadmap (superimposed onto 3D arteriograms, and automatically adjusted). The application of this software for identifying HCC-feeders and embolization of tumors has shown to yield improved technical (e.g. enabling embolization with an adequate safety margin) and clinical outcome (e.g. increased progression-free survival) compared to DSA control alone. Additionally, this software can aid reduction of intraoperative radiation exposure by reducing the number of required DSA runs and total fluoroscopy time.

Limitations of this thesis include that most studies reviewed were published between 2013-2020, many of which conducted by the same authors and centers, involving relatively small cohorts. Furthermore, a general lack of studies discussing clinical efficacy of CBCT and AFDs results in difficulties providing adequate assessments regarding the clinical benefits and short-comings.