The Role of Cone-Beam CT in Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: A Systematic Review and Meta-analysis. J Vasc Interv Radiol. 2017;28:334-341. [PMID: 28109724 DOI: 10.1016/j.jvir.2016.11.037]

Cone Beam computed tomography (CBCT) applications in image-guided minimally invasive procedures

Cone-Beam computed tomography (CBCT) obtains three-dimensional images using a two-dimensional detector. The use of CBCT in treatment planning and evaluation increases the safety and efficacy of minimally invasive procedures. This article reviews the technical considerations, main clinical applications, and future directions of CBCT in vascular and interventional radiology and interventional neuroradiology.

Radiation dose during transarterial chemoembolization and associated factors

PURPOSE

To provide detailed reports on radiation doses during transarterial chemoembolization (TACE) in the cone-beam computed tomography (CBCT) era and to identify the associated factors.

METHODS

This retrospective study included 385 consecutive patients who underwent initial conventional TACE for hepatocellular carcinoma (HCC) between January 2016 and December 2017. In most cases, CBCT was performed at the common hepatic artery or celiac axis to confirm the location of the tumor and the three-dimensional hepatic artery anatomy. Superselective TACE was performed for all technically feasible cases. Information on total dose area product (DAP), total cumulative air kerma (CAK), fluoroscopy time, and DAP and CAK of each digital subtraction angiography (DSA) and CBCT scan was recorded. Multiple linear regression analysis was performed to identify the factors associated with increased DAP during TACE.

RESULTS

The mean values of total DAP and CAK were 165.2 ± 81.2 (Gy·cm²) and 837.1 ± 571.0 (mGy), respectively. The mean fluoroscopy time was 19.1 ± 10.3 min. The mean DAP caused by fluoroscopy, DSA, and CBCT was 51.8 ± 43.9, 28.0 ± 24.1, and 83.9 ± 42.1 Gy·cm², respectively. Male sex, a high body mass index, largest tumor size > 3 cm, presence of aberrant right and left hepatic arteries, and superselective TACE were identified as independent predictors of increased total DAP during TACE.

CONCLUSION

We were able to provide detailed reports on radiation doses during TACE and associated factors.

Improved vascular depiction and image quality through deep learning reconstruction of CT hepatic arteriography during transcatheter arterial chemoembolization

PURPOSE

To evaluate the effect of deep learning reconstruction (DLR) on vascular depiction, tumor enhancement, and image quality of computed tomography hepatic arteriography (CTHA) images acquired during transcatheter arterial chemoembolization (TACE).

METHODS

Institutional review board approval was obtained. Twenty-seven patients (18 men and 9 women, mean age, 75.7 years) who underwent CTHA immediately before TACE were enrolled. All images were reconstructed using three reconstruction algorithms: hybrid-iterative reconstruction (hybrid-IR), DLR with mild strength (DLR-M), and DLR with strong strength (DLR-S). Vascular depiction, tumor enhancement, feeder visualization, and image quality of CTHA were quantitatively and qualitatively assessed by two radiologists and compared between the three reconstruction algorithms.

RESULTS

The mean signal-to-noise ratios (SNR) of sub-segmental arteries and sub-sub-segmental arteries, and the contrast-to-noise ratio (CNR) of tumors, were significantly higher on DLR-S than on DLR-M and hybrid-IR (P < 0.001). The mean qualitative score for sharpness of sub-segmental and sub-sub-segmental arteries was significantly better on DLR-S than on DLR-M and hybrid-IR (P < 0.001). There was no significant difference in the feeder artery detection rate of automated feeder artery detection software among three reconstruction algorithms (P = 0.102). The contrast, continuity, and confidence level of feeder artery detection was significantly better on DLR-S than on DLR-M (P = 0.013, 0.005, and 0.001) and hybrid-IR (P < 0.001, P = 0.002, and P < 0.001). The weighted kappa values between two readers for qualitative scores of feeder artery visualization were 0.807-0.874. The mean qualitative scores for sharpness, granulation, and diagnostic acceptability of CTHA were better on DLR-S than on DLR-M and hybrid-IR (P < 0.001).

CONCLUSIONS

DLR significantly improved the SNR of small hepatic arteries, the CNR of tumor, and feeder artery visualization on CTHA images. DLR-S seems to be better suited to routine CTHA in TACE than does hybrid-IR.

The efficacy of cone-beam computed tomography-guided transcatheter arterial chemoembolization in hepatocellular carcinoma survival: A systematic review

Cone-beam computed tomography (CBCT)-guided transcatheter arterial chemoembolization (TACE) represents an alternative treatment option for advanced hepatocellular carcinoma (HCC) patients, yet a comprehensive evaluation of CBCT guidance on this procedure and CBCT's impact on patient survival remains lacking. We aimed to assess the efficacy and benefits of CBCT-guided TACE in improving survival outcomes for patients with HCC and show the importance of CBCT in interventional radiology. Meta-analysis was conducted to evaluate CBCT-guided TACE compared to conventional TACE in the treatment of HCC. PubMed and Cochrane library databases were searched for studies published. Outcomes of interest included 1- or 3-year local progression-free survival (LPFS) rates, overall survival (OS) rates, and tumor response results. A total of eight studies were included in the meta-analysis, comprising 1176 patients. The analysis showed that CBCT-guided TACE improved 1-year LPFS (odds ratio [OR] = 2.81, P < 0.001), 3-year (OR = 4.42, P = 0.002), and the 3-year OS rates (OR = 3.03, Confidence Interval = 1.65-11.80, P = 0.14) compared to conventional TACE. CBCT-guided TACE enhances survival outcomes for patients with HCC; by addressing this research gap, our study endeavors to encourage clinicians and researchers to pursue this medical technology by providing a robust synthesis of current evidence.

Cone Beam Computed Tomography for the Interventional Oncologist: A Practical Approach

Transarterial treatment of liver tumors is becoming increasingly common and is considered first- or second-line therapy for many tumor types and stages. Such therapies are heavily dependent on imaging during the procedures; while angiography remains the mainstay of intraprocedural therapies, cone beam computed tomography (CBCT) is becoming increasingly commonly used to guide therapy. This article describes the role of CBCT during transarterial therapies and offers guidance as to how CBCT can be optimally used for these procedures.

AAPM Medical Physics Practice Guideline 14.a: Yttrium-90 microsphere radioembolization

Radioembolization using Yttrium-90 (90 Y) microspheres is widely used to treat primary and metastatic liver tumors. The present work provides minimum practice guidelines for establishing and supporting such a program. Medical physicists play a key role in patient and staff safety during these procedures. Products currently available are identified and their properties and suppliers summarized. Appropriateness for use is the domain of the treating physician. Patient work up starts with pre-treatment imaging. First, a mapping study using Technetium-99m (Tc-99m ) is carried out to quantify the lung shunt fraction (LSF) and to characterize the vascular supply of the liver. An MRI, CT, or a PET-CT scan is used to obtain information on the tumor burden. The tumor volume, LSF, tumor histology, and other pertinent patient characteristics are used to decide the type and quantity of 90 Y to be ordered. On the day of treatment, the appropriate dose is assayed using a dose calibrator with a calibration traceable to a national standard. In the treatment suite, the care team led by an interventional radiologist delivers the dose using real-time image guidance. The treatment suite is posted as a radioactive area during the procedure and staff wear radiation dosimeters. The treatment room, patient, and staff are surveyed post-procedure. The dose delivered to the patient is determined from the ratio of pre-treatment and residual waste exposure rate measurements. Establishing such a treatment modality is a major undertaking requiring an institutional radioactive materials license amendment complying with appropriate federal and state radiation regulations and appropriate staff training commensurate with their respective role and function in the planning and delivery of the procedure. Training, documentation, and areas for potential failure modes are identified and guidance is provided to ameliorate them.

Usefulness of tumor perfusion on cone-beam CT after hepatic arterial infusion port implantation for evaluating tumor response to hepatic arterial infusion chemotherapy in hepatocellular carcinoma treatment

PURPOSE

To compare tumor perfusion on cone-beam computed tomography (CBCT) after hepatic artery infusion port implantation with the tumor response to hepatic arterial infusion chemotherapy (HAIC) in patients with hepatocellular carcinoma (HCC).

METHODS

This retrospective study was conducted in patients with advanced HCC treated with HAIC from 2015 to 2020. We performed CBCT with contrast injection via a port on the day following implantation. We classified tumor perfusion on CBCT into three groups: hyperperfusion, isoperfusion, and hypoperfusion. We also evaluated tumor response to HAIC on follow-up images using RECIST 1.1 and compared it with tumor perfusion on CBCT.

RESULTS

This study included 206 tumors in 193 patients (mean: 60.5 years) with HCC. There were 100 hyperperfusion tumors (48.5%), 92 isoperfusion tumors (44.7%), and 14 hypoperfusion tumors (6.8%). The tumor response to HAIC included 10 tumors with a complete response (CR) (4.9%), 66 tumors with a partial response (32%), 60 tumors with stable disease (29.1%), and 70 tumors with progressive disease (34%). Hyperperfusion tumors had a 65% objective response rate (ORR) and a 92% disease control rate (DCR). Isoperfusion tumors had a 12% ORR and a 46.8% DCR, while hypoperfusion tumors had a 0% ORR and a 7.1% DCR. A CR was shown only in hyperperfusion tumors. The ORR and DCR of the three groups were different, with statistical significance (P < 0.001).

CONCLUSION

Hyperperfusion tumors on CBCT showed a better tumor response to HAIC, with a 65% ORR in patients with HCC. Tumor perfusion on CBCT after implantation of the hepatic arterial infusion port was associated with the tumor response to HAIC.

Added Value of Cone-Beam CT to Identify Arterial Supply during Genicular Artery Embolization for Knee Osteoarthritis

PURPOSE

To evaluate if the addition of cone-beam computed tomography (CT) to digital subtraction angiography (DSA) improves the identification of the genicular arteries during genicular artery embolization (GAE) for knee pain secondary to osteoarthritis (OA).

MATERIALS AND METHODS

This single-center study retrospectively analyzed 222 patients who underwent GAE for painful knee OA between May 2018 and April 2022. Intraprocedural cone-beam CT and DSA images were reviewed independently by 2 sets of interventional radiologists. DSA was performed for all patients. Technically adequate cone-beam CT was available for 205 patients (92.3%). The presence of the genicular arteries identified by cone-beam CT and DSA was compared using Φ coefficients. Embolization targets identified by both cone-beam CT and DSA were evaluated against those identified by DSA alone.

RESULTS

Genicular arteries with the highest concordance between cone-beam CT and DSA were the inferior lateral (196 vs 198; Φ = 0.3530; P < .0001), superior lateral (197 vs 200; Φ = 0.3060; P < .0001), and superior medial genicular (186 vs 161; Φ = 0.2836; P < .0001) arteries. Cone-beam CT demonstrated higher rates of detection of the inferior medial (195 vs 178; Φ = 0.04573; P = .5150) and median genicular arteries (200 vs 192; Φ = 0.04573; P = .5150). Meanwhile, genicular arteries less frequently identified by cone-beam CT were the descending genicular (197 vs 200; Φ = -0.03186; P = .6502), superior patellar (175 vs 184; Φ = 0.1332; P = .0569), and recurrent anterior tibial (156 vs 186; Φ = 0.01809; P = .7969) arteries. Cone-beam CT in combination with DSA identified 13.4% (372 vs 328) more targets compared to DSA alone.

CONCLUSIONS

Based on the results of the current study, cone-beam CT serves as a valuable adjunct for visualizing the genicular arteries during GAE, and together with DSA, it identifies more potential embolization targets.

Guidelines for the Diagnosis and Treatment of Primary Liver Cancer (2022 Edition)

Background

Primary liver cancer, of which around 75-85% is hepatocellular carcinoma in China, is the fourth most common malignancy and the second leading cause of tumor-related death, thereby posing a significant threat to the life and health of the Chinese people.

Summary

Since the publication of Guidelines for Diagnosis and Treatment of Primary Liver Cancer in China in June 2017, which were updated by the National Health Commission in December 2019, additional high-quality evidence has emerged from researchers worldwide regarding the diagnosis, staging, and treatment of liver cancer, that requires the guidelines to be updated again. The new edition (2022 Edition) was written by more than 100 experts in the field of liver cancer in China, which not only reflects the real-world situation in China but also may reshape the nationwide diagnosis and treatment of liver cancer.

Key Messages

The new guideline aims to encourage the implementation of evidence-based practice and improve the national average 5-year survival rate for patients with liver cancer, as proposed in the "Health China 2030 Blueprint."

Added Value of Cone-Beam Computed Tomography for Detecting Hepatocellular Carcinomas and Feeding Arteries during Transcatheter Arterial Chemoembolization Focusing on Radiation Exposure

Background and Objectives: This study aimed to evaluate the added value of cone-beam computed tomography (CBCT) for detecting hepatocellular carcinomas (HCC) and feeding arteries during transcatheter arterial chemoembolization (TACE). Material and methods: Seventy-six patients underwent TACE and CBCT. We subcategorized patients into groups I (61 patients: possible superselection of tumor/feeding arteries) and II (15 patients: limited superselection of tumor/feeding arteries). We evaluated fluoroscopy time and radiation dose during TACE. Two blinded radiologists independently performed an interval reading based on digital subtraction angiography (DSA) imaging only and DSA combined with CBCT in group I. Result: The mean total fluoroscopy time was 1456.3 ± 605.6 s. The mean dose-area product (DAP), mean DAP of CBCT, and mean ratio of DAP of CBCT to total DAP was 137.1 ± 69.2 Gy cm², 18.3 ± 7.1 Gy cm², and 13.3%, respectively. The sensitivity for detecting HCC increased after the additional CBCT reading, from 69.6% to 97.3% and 69.6% to 96.4% for readers 1 and 2, respectively. The sensitivity for detecting feeding arteries increased from 60.3% to 96.6% and 63.8% to 97.4% for readers 1 and 2, respectively. Conclusions: CBCT can increase sensitivity for detecting HCCs and feeding arteries without significantly increasing the radiation exposure.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Semiautomatic Cone-Beam Computed Tomography Virtual Hepatic Volumetry for Intra-Arterial Therapies

PURPOSE

To evaluate a software simulating the perfused liver volume from virtual selected embolization points on proximal enhanced cone-beam computed tomography (CT) liver angiography data set using selective cone-beam CT as a reference standard.

MATERIALS AND METHODS

Seventy-eight selective/proximal cone-beam CT couples in 46 patients referred for intra-arterial liver treatment at 2 recruiting centers were retrospectively included. A reference selective volume (RSV) was calculated from the selective cone-beam CT by manual segmentation and was used as a reference standard. The virtual perfusion volume (VPV) was then obtained using Liver ASSIST Virtual Parenchyma software on proximal cone-beam CT angiography using the same injection point as for selective cone-beam CT. RSV and VPV were then compared as absolute, relative, and signed volumetric errors (ABS_Err, RV_Err, and SV_Err, respectively), whereas their spatial correspondence was assessed using the Dice similarity coefficient.

RESULTS

The software was technically successful in automatically computing VPV in 74 of 78 (94.8%) cases. In the 74 analyzed couples, the median RSV was not significantly different from the median VPV (394 mL [196-640 mL] and 391 mL [192-620 mL], respectively; P = .435). The median ABS_Err, RV_Err, SV_Err, and Dice similarity coefficient were 40.9 mL (19.9-97.7 mL), 12.8% (5%-22%), 9.9 mL (-49.0 to 40.4 mL), and 80% (76%-84%), respectively. No significant ABS_Err, RV_Err, SV_Err, and Dice similarity coefficient differences were found between the 2 centers (P = .574, P = .612, P = .416, and P = .674, respectively).

CONCLUSIONS

Perfusion hepatic volumes simulated on proximal enhanced cone-beam CT using the virtual parenchyma software are numerically and spatially similar to those manually obtained on selective cone-beam CT.

The efficacy of TACE; how can automated feeder software help?

Background

This is a prospective study of 44 patients having 57 hepatocellular carcinoma (HCC) lesions indicated for transarterial chemoembolization (TACE) and a control group of 41 patients having 55 HCC lesions. TACE in the study group was performed on an angiography machine with an installed automated feeder detection (AFD) software (EmboGuide; Philips Healthcare, Best, The Netherlands) and in the control group was performed on a similar angiography machine (ALLURA XPER FD 20, Philips, Holland), but lacking the AFD software. The aim is to evaluate the clinical utilization of cone-beam CT (CBCT) and (AFD) software in accurate detection of (HCC) arterial feeders, the effect of (AFD) software utilization on the outcome of (TACE) and its utilization effect on fluoroscopy time and radiation dose to the patient during the (TACE) procedure.

Results

The highest percentage of agreement was between the number of arterial feeders detected by EmboGuide and the actual number of feeders detect during embolization reaching 91.2% with p value < 0.001. The residual non-intended non-embolized areas among the study group at 1-month follow-up were found in 2 out of 57 lesions compared to 9 out of 55 lesions in the control group. The average dose-area product (DAP) among the study group was less than that of the control group.

Conclusion

CBCT using AFD software provides more information about tumor feeders with consequent more efficient targeted embolization, higher success rate of TACE and less patient exposure to radiation.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Clinical course and role of embolization in patients with spontaneous rupture of hepatocellular carcinoma

Background

A diverse clinical course after the spontaneous rupture of hepatocellular carcinoma (HCC) renders nonstandardized treatment protocols.

Purpose

To evaluate clinical course and role of transcatheter arterial embolization (TAE) in patients with rupture of HCC.

Materials and methods

This retrospective study included 127 patients who were treated for ruptured HCC at single institution between 2005 and 2014. After multidisciplinary discussion, patients underwent medical management, TAE, emergency surgery or staged surgery. Patients were retrospectively divided into two groups based on the intent of treatment: curative and palliative. The rebleeding rate and 1-month and overall survival (OS) were compared between two groups. The incidence and survival of patients with intraperitoneal drop metastasis (IPDM) were also analyzed.

Results

The overall rebleeding rate in patients who underwent TAE was 3.1% (3/96). One-month mortality rate was 6.3% (8/127). The rebleeding and 1-month mortality rates were not significantly different between two groups. OS was significantly higher in the curative treatment group (median: 12.0 vs 2.2 months, p&lt;0.001). Among 96 patients who initially received TAE, ten patients underwent staged operation (10.4%). The median OS for medical management, TAE, emergency surgery and staged surgery was 2.8, 8.7, 19.1 and 71.1 months, respectively. Of all patients, 15.2% developed IPDM mostly within 1 year and their survival was poorer than that of patients without IPDM (median: 6.3 vs. 15.1 months, p&lt;0.001).

Conclusion

TAE provided effective immediate hemostasis with a low rebleeding rate and may serve as a bridge to elective surgery. IPDM frequently occurred within 1 year and manifested poor survival; thus, close surveillance should be considered for patients with spontaneous rupture of HCC.

Source-detector trajectory optimization in cone-beam computed tomography: a comprehensive review on today’s state-of-the-art

Cone-beam computed tomography (CBCT) imaging is becoming increasingly important for a wide range of applications such as image-guided surgery, image-guided radiation therapy as well as diagnostic imaging such as breast and orthopaedic imaging. The potential benefits of non-circular source-detector trajectories was recognized in early work to improve the completeness of CBCT sampling and extend the field of view (FOV). Another important feature of interventional imaging is that prior knowledge of patient anatomy such as a preoperative CBCT or prior CT is commonly available. This provides the opportunity to integrate such prior information into the image acquisition process by customized CBCT source-detector trajectories. Such customized trajectories can be designed in order to optimize task-specific imaging performance, providing intervention or patient-specific imaging settings. The recently developed robotic CBCT C-arms as well as novel multi-source CBCT imaging systems with additional degrees of freedom provide the possibility to largely expand the scanning geometries beyond the conventional circular source-detector trajectory. This recent development has inspired the research community to innovate enhanced image quality by modifying image geometry, as opposed to hardware or algorithms. The recently proposed techniques in this field facilitate image quality improvement, FOV extension, radiation dose reduction, metal artifact reduction as well as 3D imaging under kinematic constraints. Because of the great practical value and the increasing importance of CBCT imaging in image-guided therapy for clinical and preclinical applications as well as in industry, this paper focuses on the review and discussion of the available literature in the CBCT trajectory optimization field. To the best of our knowledge, this paper is the first study that provides an exhaustive literature review regarding customized CBCT algorithms and tries to update the community with the clarification of in-depth information on the current progress and future trends.

Phase I Dose-Escalation Study of Tirapazamine Chemoembolization for Unresectable Early- and Intermediate-Stage Hepatocellular Carcinoma

PURPOSE

To investigate the safety of replacing doxorubicin with tirapazamine in conventional transarterial chemoembolization (TACE) in an Asian population with hepatocellular carcinoma (HCC), and to determine the optimal tirapazamine dose for phase II studies.

MATERIALS AND METHODS

This was a phase I, 3 + 3 dose-escalation study for patients with unresectable early- and intermediate-stage HCC who received 5, 10, or 20 mg/m2 of intra-arterial (IA) tirapazamine followed by ethiodized oil/gelatin sponge-based embolization. Key eligibilities included HCCs no more than 10 cm in diameter, prior embolization allowed, Eastern Cooperative Oncology Group performance status of 0 or 1, Child-Pugh score of 5-7, and platelet count of ≥60,000 μL. Dose-limiting toxicity (DLT) was defined as any grade 3 nonhematological or grade 4 hematological toxicity, with the exception of transient elevation of aminotransferase levels after the procedure.

RESULTS

Seventeen patients were enrolled, 59% of whom had progression from a prior HCC therapy and 35% of whom had progression or recurrence after TACE. All patients tolerated the tirapazamine TACE well without any DLT or serious adverse event. Using the modified Response Evaluation Criteria in Solid Tumors, the complete response (CR) rate was 47%, and the CR + partial response rate was 65%. The median duration of response was not reached. The median time to progression was 12.6 months (95% confidence interval, 5.1-not reached). The median overall survival was 29.3 months. The selected phase II dose was set at a fixed dose of 35 mg of IA tirapazamine.

CONCLUSIONS

IA tirapazamine with transarterial embolization was well tolerated and showed promising efficacy signals in intermediate-stage HCC, justifying pursuit of a phase II study.

Paradigm shift in the treatment options of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is prevalent worldwide with suboptimal therapeutic outcomes. The advancement of therapeutic options and the development of new systemic therapies expand the armamentarium to tackle HCC. Treatment options should be provided based on the hierarchy of efficacy in a multidisciplinary perspective, instead of the traditional stage-guided scheme. In advanced HCC, lenvatinib has a comparable efficacy as sorafenib for the first-line therapy of HCC; while regorafenib, cabozantinib, and ramucirumab have been approved as second-line therapy after the failure of sorafenib. Immune checkpoint inhibitor therapy prolongs response rate and survival and enables long-term cure. Atezolizumab plus bevacizumab is superior to sorafenib as the first-line therapy for advanced HCC. Several emerging regimens by the combination of various systemic therapies are currently under clinical trials. Systemic therapy may be used in the neoadjuvant, adjuvant or even as initial therapy for intermediate-stage HCC. The paradigm shift of HCC treatment will improve patient outcomes.

Effectuality study of a 3D motion correction algorithm in C-arm CTs of severely impaired image quality during transarterial chemoembolization

Background

To evaluate effectivity of a 3D-motion correction algorithm in C-Arm CTs (CACT) with limited image quality (IQ) during transarterial chemoembolization (TACE).

Methods

From 1/2015–5/2021, 644 CACTs were performed in patients during TACE. Of these, 27 CACTs in 26 patients (18 m, 8f; 69.7 years ± 10.7 SD) of limited IQ were included. Post-processing of the original raw-data sets (CACT_Org) included application of a 3D-motion correction algorithm and bone segmentation (CACT_{MC_no_bone}). Four radiologists (R1-4) compared the images by choosing their preferred dataset and recommending repeat acquisition in case of severe IQ-impairment. R1,2 performed additional grading of intrahepatic vessel visualization, presence/extent of movement artifacts, and overall IQ.

Results

R1,2 demonstrated excellent interobserver agreement for overall IQ (ICC 0.79,p < 0.01) and the five-point vessel visualization scale before and after post-processing of the datasets (ICC 0.78,p < 0.01). Post-processing caused significant improvement, with overall IQ improving from 2.63 (CACT_Org) to 1.39 (CACT_{MC_no_bone};p < 0.01) and a decrease in the mean distance of identifiable, subcapsular vessels to the liver capsule by 4 mm (p < 0.01). This proved especially true for datasets with low parenchymal and high hepatic artery contrast. A good interobserver agreement (ICC = 0.73) was recorded concerning the presence of motion artifacts, with significantly less discernible motion after post-processing (CACT_Org:1.31 ± 1.67, CACT_{MC_no_bone}:1.00 ± 1.34, p < 0.01). Of the 27 datasets, ≥ 23 CACT_{MC_no_bone} were preferred, with identical datasets chosen by the readers to show benefit from the algorithm.

Conclusion

Application of a 3D-motion correction algorithm significantly improved IQ in diagnostically limited CACTs during TACE, with the potential to decrease repeat acquisitions.

Precision Imaging Guidance in the Era of Precision Oncology: An Update of Imaging Tools for Interventional Procedures

Interventional oncology (IO) procedures have become extremely popular in interventional radiology (IR) and play an essential role in the diagnosis, treatment, and supportive care of oncologic patients through new and safe procedures. IR procedures can be divided into two main groups: vascular and non-vascular. Vascular approaches are mainly based on embolization and concomitant injection of chemotherapeutics directly into the tumor-feeding vessels. Percutaneous approaches are a type of non-vascular procedures and include percutaneous image-guided biopsies and different ablation techniques with radiofrequency, microwaves, cryoablation, and focused ultrasound. The use of these techniques requires precise imaging pretreatment planning and guidance that can be provided through different imaging techniques: ultrasound, computed tomography, cone-beam computed tomography, and magnetic resonance. These imaging modalities can be used alone or in combination, thanks to fusion imaging, to further improve the confidence of the operators and the efficacy and safety of the procedures. This article aims is to provide an overview of the available IO procedures based on clinical imaging guidance to develop a targeted and optimal approach to cancer patients.

The Role of Catheter-Directed CT-Angiography in Radioembolisation

Radioembolisation is an established transarterial therapy for hepatocellular carcinoma and liver metastasis. Success of radioembolisation depends on meticulous angiography and accurate dosimetry. Intra-procedure catheter-directed CT-angiography is commonly performed to improve the efficacy and safety of radioembolisation. This review article will (1) introduce the differences between cone beam CT and hybrid angiography-CT, and (2) describe the benefits of catheter-directed CT-angiography in radioembolisation from both an interventional radiology and nuclear medicine perspective.

Utility of Cone-Beam CT for Bronchial Artery Embolization and Chemoinfusion: A Single-Institution Retrospective Case Series

PURPOSE

To describe the technique and document utility of adjunctive cone-beam CT (CBCT) in patients undergoing bronchial artery embolization (BAE) or chemoinfusion (BAC).

MATERIALS AND METHODS

Between August 2010 and February 2021, 26 patients (62 bronchial arteries) were evaluated with CBCT in addition to the usual digital subtraction angiography (DSA) during BAE or BAC. 19 patients (43 arteries) underwent BAE for hemoptysis; 7 patients (19 arteries) had BAC for palliation of lung malignancy. Retrospective review of procedural reports and the archived DSA and CBCT images was assessed for (1) whether CBCT findings added unique diagnostic information prior to treatment of target arteries compared to DSA alone; and (2) whether these unique CBCT findings led to modification of embolization or chemoinfusion technique.

RESULTS

In 61 of 62 (98%) interrogated bronchial arteries, CBCT provided additional unique diagnostic information over planar DSA, primarily cross-sectional assessment of the spinal canal for spinal arteries. In 46/62 (74%) of the bronchial arteries the unique information did not lead to a change in therapeutic technique. In 15 bronchial arteries (24%), the added information from CBCT led to change in embolization and/or chemoinfusion technique. Embolization of one small unrecognized spinal artery branch (1.6%), which was missed intra-procedurally but retrospectively seen on CBCT led to transient spinal cord ischemia.

CONCLUSIONS

These results suggest that adjunctive use of CBCT technique may improve diagnostic confidence from information provided by DSA in nearly all cases of BAE and BAC leading to improved therapeutic targeting or change in technique of embolization or chemoinfusion.

Accuracy of a CBCT-based virtual injection software for vessel detection during hepatic arterial embolization

PURPOSE

To assess the accuracy, sensitivity, positive predictive value (PPV) and interobserver agreement of a virtual injection (VI) software that simulates selective arterial injection from nonselective cone-beam CT (CBCT) arteriography.

METHODS

From March 2019 to May 2020, 20 consecutive patients in whom a nonselective injected CBCT and a selective CT angiography (CTA) were completed in the same procedure, were retrospectively included. The position of the microcatheter tip used for selective CTA injection was identified. The VI was simulated from the exact same point on the nonselective CBCT and the two volumes were merged. VI was compared to the real injection on the selective CTA. Three interventional radiologists evaluated the accuracy using a 6-point scale (Perfect; Good; Fair; Incorrect Origin; False Negative; Non existing). Sensitivity, PPV, and Fleiss' kappa were calculated. Numerical variables were presented as means ± standard deviations.

RESULTS

Twenty procedures and 195 vessel segments were analyzed. Most vessels were 4th order (57/195; 29%) and 5th order (96/195; 49%). VI was classified as perfect to good in 96.8% ± 1.4 of 1st-3rd order arteries and in 83.4% ± 0.4 of 4th-5th order arteries. Interobserver agreement was substantial (Fleiss' kappa = 0.79; 95% confidence interval = 0.73-0.84, P < 0.01). False negatives were reported with a mean of 9.4% ± 0.3. Average sensitivity was 90.6% ± 0.3 and average PPV was 92.7% ± 0.02. Fourteen false positives were noted.

CONCLUSION

CBCT-based VI software accurately simulated distal injections in the liver with high sensitivity and a substantial interobserver agreement.

Quantitative and qualitative evaluation of liver metastases with intraprocedural cone beam CT prior to transarterial radioembolization as a predictor of treatment response

Purpose

To investigate, by quantitative and qualitative enhancement measurements, the correlation between tumor enhancement on cone beam computed tomography (CBCT) images and treatment response at 6 months in patients undergoing transarterial radioembolization (TARE) for liver metastases.

Materials and Methods

36 patients (56% male; median age 62.5 years) with 104 metastases were retrospectively included. Quantitative and qualitative enhancement of liver metastases were evaluated on CBCT images before TARE. Quantitative analysis consisted of lesion enhancement measurements (ROI HU lesion - ROI HU relative to inferior vena cava). Qualitative analysis consisted of subjective enhancement pattern analysis (diffuse, sparse, rim-like or non-enhancing). Morphologic tumor response was evaluated according to RECIST 1.1 criteria on follow-up CT or MR imaging.

Results

At a mean follow up of 6.5 ± 3.7 months, progressive disease (PD) was found in 4 patients, partial response (PR) in 11 and stable disease (SD) in 21. Relative lesion enhancement was significantly different between these groups (-37.5±154.2 HU vs. 103.8±93.4 vs. 181±144 HU in PD vs. SD vs. PR group, respectively; p<0.01). ROC analysis of relative lesion enhancement to predict progressive disease showed an area under the curve of 0.86 (p<0.01). For qualitative lesion enhancement analysis, no difference between groups was found.

Conclusion

Quantitative enhancement measurements derived from intraprocedural contrast enhanced CBCT may identify responders to TARE in patients with liver metastases.

Yttrium-90 Radioembolization Is Associated with Better Clinical Outcomes in Patients with Hepatocellular Carcinoma Compared with Conventional Chemoembolization: A Propensity Score-Matched Study

Background

Both trans-arterial radioembolization (TARE) and conventional trans-arterial chemoembolization (TACE) can effectively control hepatocellular carcinoma (HCC) in patients who are not suitable for curative resection. This study compared the effectiveness of TARE and conventional TACE as the initial trans-arterial treatment for hepatocellular carcinoma (HCC) assessed by tumor response and clinical outcomes.

Material and Methods

Data were retrospectively analyzed the propensity score-matched cohort for overall survival (OS), progression-free survival (PFS), and intrahepatic PFS in patients who have received TARE or TACE as the first HCC treatment from March 2012 to December 2017.

Results

A total of 138 patients initially treated with TARE (n = 54) or TACE (n = 84) was included in this study. Of 138 patients, median age was 59 years and the mean follow-up period was 27.6 months. TARE showed better OS (hazard ratio [HR] = 0.54, 95% confidence interval [CI] = 0.31–0.92, log-rank P = 0.02), better PFS (HR = 0.51, 95% CI = 0.36–0.97, log-rank P = 0.04), and better intrahepatic PFS (HR = 0.51, 95% CI = 0.30–0.88, log-rank P = 0.01) compared with TACE. TARE was an independent prognostic factor for OS (adjusted HR [aHR] = 0.52, 95% CI = 0.30–0.90, P = 0.02), PFS (aHR = 0.57, 95% CI = 0.35–0.94, P = 0.03), and intrahepatic PFS (aHR = 0.49, 95% CI = 0.28–0.84, P = 0.01).

Conclusion

TARE as initial trans-arterial treatment is associated with better clinical outcomes such as longer OS compared with TACE in patients with HCC.

Portal Vein Embolization Using N-Butyl Cyanoacrylate-Glue: What Impact Does a Central Vascular Plug Have?

Purpose

To examine if the addition of a central vascular plug (CVP) to portal vein embolization (PVE) with N-butyl cyanoacrylate-glue (NBCA) increases future liver remnant (FLR) growth.

Material and Methods

This is a single-center retrospective study of 115 consecutive patients with colorectal liver metastases undergoing PVE in 2013–2019. All patients were embolized with NBCA as the main embolic agent. In 2017–2019 NBCA was combined with a CVP in the central part of the right portal vein. Growth of the FLR and standardized FLR (sFLR) including degree of hypertrophy (DH) and kinetic growth rate (KGR) were analyzed, as well as procedure data such as use of cone-beam CT (CBCT), dose area product (DAP), fluoroscopy time and contrast dose.

Results

A total of 40 patients (35%) underwent PVE with a combination of CVP and NBCA. The DH was higher in these patients after 4 weeks, mean 13.6% (SD 7.8) vs. 10.5% (SD 6.4; p = 0.022), verified in multivariate analysis (coefficient 4.1, p = 0.015). A CVP did not significantly increase the resection rate (90% vs 82%, p = 0.4). Cone beam CT was used in 65 patients (57%). Use of CBCT did not affect FLR growth, and fluoroscopy time and contrast doses were not different in patients having a CBCT or not. Slightly lower DAP (median 3375 vs. 4499 cGy*cm²; p = 0.09) was seen in procedures where CBCT was used.

Conclusion

A CVP in addition to NBCA embolization was associated with increased growth of the FLR compared to NBCA alone.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-021-03014-w.

Thrombin Based Photothermal-Responsive Nanoplatform for Tumor-Specific Embolization Therapy

The specific coagulation in the tumor vasculature has the potential for the ablation of solid tumors by cutting off the blood supply. However, the safe delivery of effective vessel occluding agents in the tumor-specific embolization therapy remains challenging. Herein, it is reported that the photothermal responsive tumor-specific embolization therapy based on thrombin (Thr) is delivered by intravenous injection via the phase-change materials (PCM)-based nanoparticles. The wax sealing profile of PCM enables safe delivery and prevents the preleakage of Thr in the blood circulation. While in the tumor site, the thermal effect induced by IR780 triggers the melting of PCM and rapidly releases Thr to generate coagulation in the tumor blood vessels. Based on the safe delivery and controllable release of Thr, thermal responsive tumor-specific embolization therapy could be achieved with high efficiency and no significant damage to normal organs and tissues. The safe administration of Thr to induce vascular infarction in tumors based on PCM nanoparticles in this work shows a promising strategy for improving the therapeutic specificity and efficacy of coagulation-based tumor therapy.

Impact of cone-beam computed tomography with automated feeder detection software on the survival outcome of patients with hepatocellular carcinoma during treatment with conventional transarterial chemoembolization

Background

Inoperable hepatocellular carcinoma (HCC) is treated by conventional transarterial chemoembolization (cTACE) using cone-beam computed tomography (CBCT) or digital subtraction angiography (DSA). We compared patient survival outcomes between CBCT-cTACE with automated tumor-feeder detection (AFD) software and DSA-cTACE alone in inoperable HCC patients.

Methods

We reviewed the data of 337 HCC patients treated by CBCT-cTACE or DSA-cTACE between January 2015 and December 2019. Treatment response, progression-free survival (PFS), overall survival (OS), and complications between the CBCT-cTACE and DSA-cTACE groups were compared. Univariate and multivariate logistic regression analyses examined the potential prognostic factors affecting survival after chemoembolization.

Results

Tumor response rates in complete response, partial response, and stable disease at 1 month were 67%, 28%, and 4% in the CBCT-cTACE group and 22%, 48%, and 9% in the DSA-cTACE group, respectively. OS rates of patients in the CBCT-cTACE versus DSA-cTACE groups were 87% versus 54%, 44% versus 15%, and 34% versus 7% at 1, 3, and 5 years, respectively. The CBCT-cTACE group had significantly improved PFS (p < 0.001) and OS (p < 0.001). Multivariate analysis showed that CBCT with AFD software was an independent factor associated with longer OS (hazard ratio, 0.38; p < 0.001).

Conclusions

Compared with conventional DSA, combining selective cTACE with CBCT and AFD software leads to better tumor response and prolongs OS in patients with inoperable HCC.

Flat-panel conebeam CT in the clinic: history and current state

Research into conebeam CT concepts began as soon as the first clinical single-slice CT scanner was conceived. Early implementations of conebeam CT in the 1980s focused on high-contrast applications where concurrent high resolution ( < 200    μ m ), for visualization of small contrast-filled vessels, bones, or teeth, was an imaging requirement that could not be met by the contemporaneous CT scanners. However, the use of nonlinear imagers, e.g., x-ray image intensifiers, limited the clinical utility of the earliest diagnostic conebeam CT systems. The development of consumer-electronics large-area displays provided a technical foundation that was leveraged in the 1990s to first produce large-area digital x-ray detectors for use in radiography and then compact flat panels suitable for high-resolution and high-frame-rate conebeam CT. In this review, we show the concurrent evolution of digital flat panel (DFP) technology and clinical conebeam CT. We give a brief summary of conebeam CT reconstruction, followed by a brief review of the correction approaches for DFP-specific artifacts. The historical development and current status of flat-panel conebeam CT in four clinical areas-breast, fixed C-arm, image-guided radiation therapy, and extremity/head-is presented. Advances in DFP technology over the past two decades have led to improved visualization of high-contrast, high-resolution clinical tasks, and image quality now approaches the soft-tissue contrast resolution that is the standard in clinical CT. Future technical developments in DFPs will enable an even broader range of clinical applications; research in the arena of flat-panel CT shows no signs of slowing down.

CIRSE Standards of Practice on Hepatic Transarterial Chemoembolisation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing transarterial chemoembolisation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It will encompass all technical details reflecting European practice of different TACE procedures (Lp-TACE, DEM-TACE, DSM-TACE, b-TACE) as well as revising the existing literature on the various clinical indications (HCC, mCRC, ICC, NET). Finally, new frontiers of development will also be discussed.

In the Era of Systemic Therapy for Hepatocellular Carcinoma Is Transarterial Chemoembolization Still a Card to Play?

Conventional transarterial embolization (cTACE) has been proven to be effective for intermediate stage hepatocellular carcinoma (HCC), with a recent systematic review showing an overall survival (OS) of 19.4 months. Nevertheless, due to the rapid development of the systemic therapeutic landscape, the place of TACE is becoming questionable. Is there still a niche for TACE in the era of immunotherapy and combination treatments such as atezolizumab-bevacizumab, which has shown an OS of 19.2 months with excellent tolerance? The development of drug-eluting microspheres (DEMs) has led to the standardization of the technique, and along with adequate selection, it showed an OS of 48 months in a retrospective study. In order to increase treatment selectivity, new catheters have also been added to the TACE arsenal as well as the use of cone-beam CT (CBCT), which provides three-dimensional volumetric images and guidance during procedures. Moreover, the TACE indications have also widened. It may serve as a "bridging therapy" for liver transplantation candidates while they are on the waiting list, and it represents a valuable downstaging tool to transplantation criteria. The aim of this review is to explore the current data on the advancements of TACE and its future place amongst the growing panel of treatments.

Combined Angio-CT Systems: A Roadmap Tool for Precision Therapy in Interventional Oncology

Combined angiography-CT (angio-CT) systems, which combine traditional angiographic imaging with cross-sectional imaging, are a valuable tool for interventional radiology. Although cone-beam CT (CBCT) technology from flat-panel angiography systems has been established as an adjunct cross-sectional imaging tool during interventional procedures, the intrinsic advantages of angio-CT systems concerning superior soft-tissue imaging and contrast resolution, along with operational ease, have sparked renewed interest in their use in interventional oncology procedures. Owing to increases in affordability and usability due to an improved workflow, angio-CT systems have become a viable alternative to stand-alone flat-panel angiographic systems equipped with CBCT. This review aims to provide a comprehensive technical and clinical guide for the use of angio-CT systems in interventional oncology. The basic concepts related to the use of angio-CT systems, including concepts related to workflow setup, imaging characteristics, and acquisition parameters, will be discussed. Additionally, an overview on the clinical applications and the benefits of angio-CT systems in routine therapeutic and palliative interventional oncology procedures will be reviewed. Keywords: Ablation Techniques, CT-Angiography, Interventional-Body, Interventional-MSK, Chemoembolization, Embolization, Radiation Therapy/Oncology, Abdomen/GI, Skeletal-Axial Supplemental material is available for this article. © RSNA, 2021.

Conventional Hepatic Volumetry May Lead to Inaccurate Segmental Yttrium-90 Radiation Dosimetry

OBJECTIVE

To compare radioembolization treatment zone volumes from mapping cone beam CT (CBCT) versus planning CT/MRI and to model their impact on dosimetry.

METHODS

Y90 cases were retrospectively identified in which intra-procedural CBCT angiograms were performed. Segmental and lobar treatment zone volumes were calculated with semi-automated contouring using Couinaud venous anatomy (planning CT/MRI) or tumor angiosome enhancement (CBCT). Differences were compared with a Wilcoxon signed-rank test. Treatment zone-specific differences in segmental volumes by volumetric method were also calculated and used to model differences in delivered dose using medical internal radiation dosimetry (MIRD) at 200 and 120 Gy targets. Anatomic, pathologic, and technical factors likely affecting segmental volumes by volumetric method were evaluated.

RESULTS

Forty segmental and 48 lobar CBCT angiograms and corresponding planning CT/MRI scans were included. Median Couinaud- and CBCT-derived segmental volumes were 281 and 243 mL, respectively (p = 0.005). Differences between Couinaud and CBCT lobar volumes (right, left) were not significant (p = 0.24, p = 0.07). Couinaud overestimated segmental volumes in 28 cases by a median of 98 mL (83%) and underestimated in 12 cases by median 69 mL (20%). At a 200 Gy dose target, Couinaud estimates produced median delivered doses of 367 and 160 Gy in these 28 and 12 cases. At a 120 Gy target, Couinaud produced doses of 220 and 96 Gy. Proximal vs. distal microcatheter positioning, variant arterial anatomy, and tumor location on or near segmental watersheds were leading factors linked to volumetric differences.

CONCLUSION

Use of CBCT-based volumetry may allow more accurate, personalized dosimetry for segmental Y90 radioembolization.

The Impact of the use of C-Arm Cone-Beam CT during Chemoembolization for Hepatocellular Carcinoma

OBJECTIVE

The objective of the study was to investigate the consequences of using C-arm cone-beam computed tomography (CBCT) on super-selective catheterization of hepatic artery (HA) branches during chemoembolization of hepatocellular carcinoma.

METHODS

Two groups of patients were created according to the dates of their treatment sessions. Group A and Group B included patients who had their treatment sessions in 2004 - 2005 and 2008 - 2010, respectively. The sessions performed in 2006 and 2007 were excluded to allow for the adoption and incorporation of CBCT imaging into clinical practice. All chemoembolized HA branches were categorized according to selection order (0-1, 2, or ≥3). Other procedure variables were documented.

RESULTS

A total of 58 and 183 sessions were included in Groups A and B, respectively, for 144 patients. C-arm CBCT was used in 2 (3%) sessions and 142 (78%) sessions in groups A and B, respectively. The average number of vessels treated was significantly higher in group B (1.8) compared to group A (1.3) (P < .0001). A shift to an increased selection order in group B (0-1, 44 [24%]; 2, 85 [46%]; ≥3, 54 [30%]) was more significant (P = .0004) than that in group A (0-1, 32 [55%]; 2, 18 [31%]; ≥3, 8 [14%]). The average duration of the procedure was significantly longer in group B (P = .0002).

CONCLUSIONS

Using C-arm CBCT during chemoembolization has a positive impact on increasing the number and order of HA selected and chemoembolized. This comes at the expense of an increase in the duration of the procedure.

Anatomy-guided multimodal registration by learning segmentation without ground truth: Application to intraprocedural CBCT/MR liver segmentation and registration

Multimodal image registration has many applications in diagnostic medical imaging and image-guided interventions, such as Transcatheter Arterial Chemoembolization (TACE) of liver cancer guided by intraprocedural CBCT and pre-operative MR. The ability to register peri-procedurally acquired diagnostic images into the intraprocedural environment can potentially improve the intra-procedural tumor targeting, which will significantly improve therapeutic outcomes. However, the intra-procedural CBCT often suffers from suboptimal image quality due to lack of signal calibration for Hounsfield unit, limited FOV, and motion/metal artifacts. These non-ideal conditions make standard intensity-based multimodal registration methods infeasible to generate correct transformation across modalities. While registration based on anatomic structures, such as segmentation or landmarks, provides an efficient alternative, such anatomic structure information is not always available. One can train a deep learning-based anatomy extractor, but it requires large-scale manual annotations on specific modalities, which are often extremely time-consuming to obtain and require expert radiological readers. To tackle these issues, we leverage annotated datasets already existing in a source modality and propose an anatomy-preserving domain adaptation to segmentation network (APA2Seg-Net) for learning segmentation without target modality ground truth. The segmenters are then integrated into our anatomy-guided multimodal registration based on the robust point matching machine. Our experimental results on in-house TACE patient data demonstrated that our APA2Seg-Net can generate robust CBCT and MR liver segmentation, and the anatomy-guided registration framework with these segmenters can provide high-quality multimodal registrations.

Intraprocedural cone-beam CT with parenchymal blood volume assessment for transarterial chemoembolization guidance: Impact on the effectiveness of the individual TACE sessions compared to DSA guidance alone

PURPOSE

The objective of this retrospective single centre study was to evaluate the impact of intraprocedural cone-beam CT with parenchymal blood volume assessment (PBV-CBCT) for guidance of transarterial chemoembolization with drug-eluting beads (DEB-TACE) in HCC patients on the effectiveness (local tumour response, survival and number of individual TACE sessions) compared to guidance solely by digital subtraction angiography (DSA).

METHOD

n = 179 HCC patients (mean age, 77.4 y) undergoing DEB-TACE, with (n = 28) and without (n = 151) PBV-CBCT, using 100-300 μm microspheres loaded with epirubicin were retrospectively analysed. Tumour response according to mRECIST, overall survival and number of TACE interventions as well as laboratory parameters for liver function and inflammation were recorded. The analysis of the influence of intraprocedural PBV-CBCT was based on matched pair analysis (CBCT n = 28 vs. DSA n = 28). Gender, tumour number, tumour size and HCC risk factors were equally distributed between both groups.

RESULTS

Response rates according to mRECIST:CBCT: PD: 7%, SD: 28 %, PR: 46 %, CR: 18 %; DSA: PD: 7 %, SD: 32 %, PR: 39 %, CR: 21 % (p = 0.174). Median OS: CBCT: 44.1 months; DSA: 28.8 months (p = 0.815). Median TACE number: CBCT: 2.0; DSA: 3.0 (p = 0.046).

CONCLUSIONS

The use of intraprocedural PBV-CBCT for TACE guidance reduced the number of re-interventions, with no negative effects on tumour response and overall survival. The study findings support the use of PBV-CBCT for DEB-TACE guidance as the improved immediate feedback leads to a considerable increase of the treatment efficiency and helps to avoid unnecessary re-interventions.

Efficacy and Safety of Cone-Beam Computed Tomography-Derived Augmented Fluoroscopy Combined with Endobronchial Ultrasound in Peripheral Pulmonary Lesions

BACKGROUND

The diagnostic yield of peripheral pulmonary lesions (PPLs) using radial endobronchial ultrasound (EBUS) remains challenging without navigation systems. Cone-beam computed tomography-derived augmented fluoroscopy (CBCT-AF) represents a recently developed technique, and its clinical utility remains to be investigated.

OBJECTIVES

The aim of this study was to investigate the diagnostic yield of transbronchial biopsy (TBB) using a combination of CBCT-AF and radial EBUS.

METHODS

We recruited consecutive patients with PPLs who underwent radial EBUS-guided TBB, with or without AF, between October 2018 and July 2019. Following propensity score 1:1 matching, we recorded the procedure-related data and measured their efficacy and safety.

RESULTS

While 72 patients received EBUS-plus-AF, 235 patients received EBUS only. We included 53 paired patients following propensity score matching. The median size of lesions was 2.8 and 2.9 cm in the EBUS-plus-AF group and EBUS-only group, respectively. Diagnostic yield was higher in the former group (75.5 vs. 52.8%; p = 0.015). The diagnostic yield for the EBUS-plus-AF group was significantly higher for lesions ≤30 mm (73.5 vs. 36.1%; p = 0.002). Moreover, there was no significant difference in the complication rates (3.8 vs. 5.7%; p = 1.000). Twenty-four nodules (45.3%) were invisible by fluoroscopy in the EBUS-plus-AF group. All of them were identifiable on CBCT images and successfully annotated for AF. The mean radiation dose of total procedure, CBCT, and fluoroscopy was 19.59, 16.4, and 3.17 Gy cm2, respectively.

CONCLUSIONS

TBB using a combination of CBCT-AF and EBUS resulted in a satisfactory diagnostic yield and safety.

Review of Intra-Arterial Therapies for Colorectal Cancer Liver Metastasis

Simple Summary

Colorectal cancer liver metastasis occurs in more than 50% of patients with colorectal cancer and is thought to be the most common cause of death from this cancer. The mainstay of treatment for inoperable liver metastasis has been combination systemic chemotherapy with or without the addition of biological targeted therapy with a goal for disease downstaging, for potential curative resection, or more frequently, for disease control. For patients with dominant liver metastatic disease or limited extrahepatic disease, liver-directed intra-arterial therapies including hepatic arterial chemotherapy infusion, chemoembolization and radioembolization are alternative treatment strategies that have shown promising results, most commonly in the salvage setting in patients with chemo-refractory disease. In recent years, their role in the first-line setting in conjunction with concurrent systemic chemotherapy has also been explored. This review aims to provide an update on the current evidence regarding liver-directed intra-arterial treatment strategies and to discuss potential trends for the future.

Abstract

The liver is frequently the most common site of metastasis in patients with colorectal cancer, occurring in more than 50% of patients. While surgical resection remains the only potential curative option, it is only eligible in 15–20% of patients at presentation. In the past two decades, major advances in modern chemotherapy and personalized biological agents have improved overall survival in patients with unresectable liver metastasis. For patients with dominant liver metastatic disease or limited extrahepatic disease, liver-directed intra-arterial therapies such as hepatic arterial chemotherapy infusion, chemoembolization and radioembolization are treatment strategies which are increasingly being considered to improve local tumor response and to reduce systemic side effects. Currently, these therapies are mostly used in the salvage setting in patients with chemo-refractory disease. However, their use in the first-line setting in conjunction with systemic chemotherapy as well as to a lesser degree, in a neoadjuvant setting, for downstaging to resection have also been investigated. Furthermore, some clinicians have considered these therapies as a temporizing tool for local disease control in patients undergoing a chemotherapy ‘holiday’ or acting as a bridge in patients between different lines of systemic treatment. This review aims to provide an update on the current evidence regarding liver-directed intra-arterial treatment strategies and to discuss potential trends for the future.

Comparison of the effectiveness of celiac versus common hepatic artery injection for the detection of hepatocellular carcinoma and of the feeding artery on cone-beam computed tomographs obtained during hepatic angiography

Background

Cone-beam computed tomography (CBCT) has been widely used during transcatheter arterial chemoembolization for hepatocellular carcinoma.

Purpose

To evaluate the sensitivity of CBCT for the detection of hepatocellular carcinomas and the tumor feeders by comparing celiac artery (CA) and common hepatic artery (CHA) injection.

Material and methods

We retrospectively enrolled 30 patients (52 hepatocellular carcinoma lesions) who had undergone CBCT-assisted transcatheter arterial chemoembolization. In 17 procedures (28 hepatocellular carcinomas) we acquired CBCT scans using CA injections (CBCT-CA) and in 18 (24 hepatocellular carcinomas) we used CHA injections (CBCT-CHA). Of the 30 patients, 5 underwent CBCT-CA and CBCT-CHA at different transcatheter arterial chemoembolization procedures. We performed inter-group comparisons of the detectability of hepatocellular carcinoma, the feeding artery, the intrahepatic artery branch order, and the tumor-to-liver contrast.

Results

CBCT-CA detected all 28 hepatocellular carcinomas and 27 of their feeders (96.4%); CBCT-CHA identified 22 of 24 hepatocellular carcinomas (91.7%) and 21 of their feeders (95.5%). There was no significant inter-group difference in the detectability of hepatocellular carcinoma lesions (p = 0.21) or feeding arteries (p = 0.69). CBCT-CHA was superior for the assessment of the tumor-to-liver contrast and the intrahepatic artery branch order (both: p < 0.01).

Conclusion

CBCT-CA and CBCT-CHA were equally useful for the detection of hepatocellular carcinoma and of the feeding artery, although CBCT-CHA yields better visualization of hepatocellular carcinoma and the hepatic artery. Thus CA injection seems sufficient for lesion and vessel detection when the insertion of an angiographic catheter into the CHA is difficult.

Evaluation of a Motion Correction Algorithm for C-Arm Computed Tomography Acquired During Transarterial Chemoembolization

Purpose

The aim of this retrospective study was to evaluate the feasibility of a motion correction 3D reconstruction prototype technique for C-arm computed tomography (CACT).

Material and Methods

We included 65 consecutive CACTs acquired during transarterial chemoembolization of 54 patients (47 m,7f; 67 ± 11.3 years). All original raw datasets (CACT_Org) underwent reconstruction with and without volume punching of high-contrast objects using a 3D image reconstruction software to compensate for motion (CACT_{MC_bone};CACT_{MC_no bone}). Subsequently, the effect on image quality (IQ) was evaluated using objective (image sharpness metric) and subjective criteria. Subjective criteria were defined by vessel geometry, overall IQ, delineation of tumor feeders, the presence of foreign material-induced artifacts and need for additional imaging, assessed by two independent readers on a 3-(vessel geometry and overall IQ) or 2-point scale, respectively. Friedman rank-sum test and post hoc analysis in form of pairwise Wilcoxon signed-rank test were computed and inter-observer agreement analyzed using kappa test.

Results

Objective IQ as defined by an image sharpness metric, increased from 273.5 ± 28 (CACT_Org) to 328.5 ± 55.1 (CACT_{MC_bone}) and 331 ± 57.8 (CACT_{MC_no bone}; all p < 0.0001). These results could largely be confirmed by the subjective analysis, which demonstrated predominantly good and moderate inter-observer agreement, with best agreement for CACT_{MC_no bone} in all categories (e.g., vessel geometry: CACT_Org: κ = 0.51, CACT_{MC_bone}: κ = 0.42, CACT_{MC_no bone}: κ = 0.69).

Conclusion

The application of a motion correction algorithm was feasible for all data sets and led to an increase in both objective and subjective IQ parameters.

Level of Evidence

3

"Primum Non Nocere" in Interventional Oncology for Liver Cancer: How to Reduce the Risk for Complications?

Interventional oncology represents a relatively new clinical discipline based upon minimally invasive therapies applicable to almost every human organ and disease. Over the last several decades, rapidly evolving research developments have introduced a newer generation of treatment devices, reagents, and image-guidance systems to expand the armamentarium of interventional oncology across a wide spectrum of disease sites, offering potential cure, control, or palliative care for many types of cancer patients. Due to the widespread use of locoregional procedures, a comprehensive review of the methodologic and technical considerations to optimize patient selection with the aim of performing a safe procedure is mandatory. This article summarizes the expert discussion and report from the Mediterranean Interventional Oncology Live Congress (MIOLive 2020) held in Rome, Italy, integrating evidence-reported literature and experience-based perceptions as a means for providing guidance on prudent ways to reduce complications. The aim of the paper is to provide an updated guiding tool not only to residents and fellows but also to colleagues approaching locoregional treatments.

Characterization of Liver Metastases During Catheter-Directed Liver Interventions: A Comparison between Dual Phase Cone-Beam Computed Tomography and Conventional Contrast-Enhanced Computed Tomography

Objectives:

To compare the diagnostic performance of intra-arterial dual phase cone-beam computed tomography (DP-CBCT) with contrast-enhanced computed tomography (CE-CT) when characterizing tumor burden in patients with metastatic liver cancer.

Materials and Methods:

This retrospective study included 29 patients with colorectal (n =10), breast (n = 9) and neuroendocrine (n = 10) liver metastases, referred for catheter-directed treatment. Tumor type, number, maximum size, and appearance were assessed. Paired-sample t-tests compared image quality, tumor numbers, and diameters between imaging modalities.

Results:

Image quality was not different between DP-CBCT and CE-CT (p = 0.9). In 18 patients (62%) DP-CBCT and CE-CT showed diffuse, uncountable metastases in the liver. Of the remaining 11 patients, DP-CBCT identified two patients with diffuse tumors that appeared as a sum of 17 distinct metastases on CE-CT. In the remaining nine patients a total of 102 metastases were found using both DP-CBCT and CE-CT. Tumor detection accuracy was 98% in DP-CBCT and 67% in CE-CT (p = 0.025). Metastases were larger in diameter on DP-CBCT: colorectal: 57 +/– 9.5 mm versus 43 +/– 8.3 mm (p = 0.02); breast: 57 +/– 10 mm versus 43 +/– 8.5 mm (p = 0.03) and neuroendocrine: 56 +/– 6.3 mm versus 51 +/– 5.8 mm (p = 0.01). Rim enhancement appeared in 100% of patients with colorectal and 89% of patients with breast metastases on DP-CBCT, but was variable on CE-CT. Neuroendocrine tumors had variable rim enhancement within the same patient and across imaging modalities.

Conclusions:

DP-CBCT of the liver may demonstrate larger metastatic tumor burden and lesion size with a variable contrast enhancement compared to CE-CT.

Paraplegia after transcatheter artery chemoembolization in a child with clear cell sarcoma of the kidney: A case report

BACKGROUND

Transcatheter arterial chemoembolization (TACE) is a common treatment for inoperable malignant renal tumors. However, a series of complications may follow the TACE treatment. Spinal cord injury caused by the embolization of intercostal or lumbar arteries is extremely rare.

CASE SUMMARY

We describe a case with quite uncommon spinal cord injury after TACE in a 3-year-old child with clear cell sarcoma of the kidney. Sensory impairment beneath the T10 dermatomes and paraplegia on the day after TACE were found in this patient. Unfortunately, sustained paraplegia still existed for more than 2 mo after TACE despite the large dose of steroids and supportive therapy.

CONCLUSION

We should draw attention to an uncommon complication of paraplegia after TACE treatment in malignant renal tumors. Although it is rare, the result is disastrous.

Intra-procedural dual phase cone beam computed tomography has a better diagnostic accuracy over pre-procedural MRI and MDCT in detection and characterization of HCC in cirrhotic patients undergoing TACE procedure

PURPOSE

This study was directed to compare diagnostic accuracy of dual-phase cone beam computed tomography (DP-CBCT) vs pre-procedural second line imaging modality (SLIM [multidetector computed tomography and magnetic resonance imaging]) to detect and characterize hepatocellular carcinoma (HCC) in cirrhotic patients with indication for trans-arterial chemoembolization (TACE).

METHODS

This is a single centre, retrospective, and observational study. Exclusion criteria were not-assisted DP-CBCT TACE, and unavailable follow-up SLIM. We evaluated 280 consecutive patients (January/2015-Febraury/2019). Seventy-two patients were eligible. Three radiologists in consensus reviewed: pre-procedural SLIM, DP-CBCT, and SLIM at follow-up, with 4 months of interval between each reading. Hyper-vascular foci (HVF) were detected and characterized. Diameter was recorded. Radiological behaviour, according to LI-RADS criteria, of HFV throughout follow-up time was the reference standard. Diagnostic accuracy was calculated for pre-procedural SLIM and DP-CBCT and evaluated through receiver operating characteristic curve. HVF only visible on DP-CBCT (defined as occult) were analysed. Tumour diameters were compared.

RESULTS

Median time between pre-procedural SLIM and DP-CBCT and between DP-CBCT and definitive radiological diagnosis of HVF were 46.0 days (95%CI 36.5-55.0) and 30.5 days (95%CI 29.0-33.0), respectively. DP-CBCT had a better diagnostic performance than pre-examination SLIM (sensitivity 99%vs78%; specificity 89%vs85%; PPV 99%vs99%; NPV 92%vs30%; and accuracy 94%vs79%). DP-CBCT diagnosed 63 occult HVF. Occult HCC were 54/243 (22.2%). Six were occult angiomas. Three were false positive. Mean diameter was significantly higher in DP-CBCT vs pre-procedural SLIM (+7.5% [95%CI 3.7-11.3], p < 0.05).

CONCLUSIONS

DP-CBCT has a better diagnostic accuracy and NPV than pre-procedural SLIM in cirrhotic patients with indication for TACE.

A systematic review of automated feeder detection software for locoregional treatment of hepatic tumors

PURPOSE

The purpose of this study was to perform a systematic review of current literature describing the efficacy and technical outcomes of transarterial liver therapies using automated feeder detection (AFD) software.

MATERIALS AND METHODS

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A structured search was performed in the PubMed, SCOPUS, and Embase databases of patients undergoing locoregional therapy of liver tumors utilizing AFD software. Demographic data, procedure data (including radiometrics) and tumor response rate were recorded. Where available, performance of AFD was compared to conventional digital subtraction angiography (DSA) and cone-beam CT (CBCT) without AFD.

RESULTS

A total of 14 full-text manuscripts met inclusion criteria, comprising 1042 tumors in 604 patients (305 men, 156 women; mean age, 68.6±6.0 [SD] years), including 537 patients with hepatocellular carcinoma, 8 with metastases from neuroendocrine tumors, and 59 patients without reported etiology. Reported sensitivity of AFD ranged between 86% and 98.5%, compared to DSA alone (38% - 64%) or DSA in combination with CBCT (69% - 81%). Three studies reported tumor response by modified response evaluation criteria in solid tumors (mRECIST) guidelines, with complete response in the range of 60% - 69%.

CONCLUSION

AFD is a promising new technology for the identification of intrahepatic and extrahepatic tumor-feeding arteries and should be considered a useful adjunct to conventional DSA and CBCT in the treatment of liver tumors.

Comparison of radiation dose and image quality between flat panel computed tomography and multidetector computed tomography in a hybrid CT-angiography suite

The purpose of this study was to compare, using the same radiation dose and image quality metrics, flat panel computed tomography (FPCT) to multidetector CT (MDCT) in interventional radiology. A single robotic angiography system with FPCT was compared to a single MDCT system, both installed in a hybrid CT-angiography laboratory and both operating under automatic exposure control. Radiation dose was measured on the central axis (D_c ) of a CT dosimetry phantom 30 cm in diameter and 60 cm in length using default protocols for FPCT and MDCT with the imaged length in MDCT matched to the field of view of FPCT. The noise power spectrum (NPS), modulation transfer function (MTF), and z-axis resolution were measured using the same phantom. Iodine contrast to noise ratio (CNR) was also measured. Radiation dose (D_c ) was 41%-69% lower in MDCT compared to FPCT when default protocols and automatic exposure control were used. While spatial resolution could generally be matched with appropriate choice of kernel in MDCT, MTF dropped more quickly at higher spatial frequency for MDCT than FPCT. Image noise was 49%-120% higher for MDCT compared to FPCT for comparable in-plane spatial resolution. Z-axis resolution was slightly better for MDCT than FPCT, while iodine CNR depended on protocol selection. Radiation dose was much lower for MDCT compared to FPCT, but image noise was much higher. Matching image noise in MDCT to FPCT would result in similar radiation doses. Iodine contrast depended on dose modulation settings for MDCT.

2019 Update of Indian National Association for Study of the Liver Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri II Recommendations

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality, and healthcare expenditure in patients with chronic liver disease in India. The Indian National Association for Study of the Liver (INASL) had published its first guidelines on diagnosis and management of HCC (The Puri Recommendations) in 2014, and these guidelines were very well received by the healthcare community involved in diagnosis and management of HCC in India and neighboring countries. However, since 2014, many new developments have taken place in the field of HCC diagnosis and management, hence INASL endeavored to update its 2014 consensus guidelines. A new Task Force on HCC was constituted that reviewed the previous guidelines as well as the recent developments in various aspects of HCC that needed to be incorporated in the new guidelines. A 2-day round table discussion was held on 5th and 6th May 2018 at Puri, Odisha, to discuss, debate, and finalize the revised consensus statements. Each statement of the guideline was graded according to the Grading of Recommendations Assessment Development and Evaluation system with minor modifications. We present here the 2019 Update of INASL Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri-2 Recommendations.