Improved Visibility of Metastatic Disease in the Liver During Intra-Arterial Therapy Using Delayed Arterial Phase Cone-Beam CT

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.

Exploring software navigation tools for liver tumour angiography: a scoping review

INTRODUCTION

Liver cancer presents a growing global health concern, necessitating advanced approaches for intervention. This review investigates the use and effectiveness of software navigation in interventional radiology for liver tumour procedures.

METHODS

In accordance with Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, a scoping review was conducted of the literature published between 2013 and 2023 sourcing articles through MEDLINE, Scopus, CINAHL and Embase. Eligible studies focused on liver cancer, utilised cone-beam computed tomography (CBCT), and employed software for intervention. Twenty-one articles were deemed eligible for data extraction and analysis.

RESULTS

Categorised by type, software applications yielded diverse benefits. Feeder detection software significantly enhanced vessel identification, reducing non-target embolisation by up to 43%. Motion correction software demonstrated a 20% enhancement in image quality, effectively mitigating breathing-induced motion artefacts. Liver perfusion software facilitated efficient tumour targeting while simultaneously reducing the occurrence of side effects. Needle guide software enabled precise radiofrequency ablation needle placement. Additionally, these software applications provided detailed anatomical simulations. Overall, software integration resulted in shorter procedures, reduced radiation exposure and decreased contrast media usage.

CONCLUSION

This scoping review highlights the innovative yet relatively underexplored role of software navigation for liver tumour procedures. The integration of software applications not only enhances procedural efficiency but also bolsters operator confidence, and contributes to improved patient outcomes. Despite the current lack of uniformity and standardisation, these software-driven advancements hold significant promise for transforming liver tumour interventions. To realise these benefits, further research is needed to explore the clinical impact and optimal utilisation of software navigation tools in interventional radiology.

An alternative second performance of contrast-enhanced ultrasound for large focal liver lesion is necessary for sufficient characterization

Focal liver lesions (FFLs) evaluated using contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) may have the same or similar findings or substantial discrepant findings. Such phenomenon can be found in two performances of CEUS that the second performance of CEUS conducted shortly following the initial performance of CEUS. Discrepancy of two performances of CEUS for FFLs occurring in the same patient at a short internal has not been well addressed, which raises challenge for CEUS for the evaluation of FFLs. In this case study, such phenomenon is illustrated and implication is obtained.

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.

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.

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.

Utility of 'dual phase' cone beam computed tomography during radioembolisation in patients with hepatocellular carcinoma: what is really changing in flow dynamics before and after 90Y delivery?

Purpose

The aims of the study were: 1) to compare two phases of dual-phase cone beam computed tomography (DP-CBCT) achieved before and after Yttrium-90 (⁹⁰Y) administration and to evaluate additional benefits during radioembolisation (RE) procedures; and 2) to compare DP-CBCT with pre-procedure contrast enhanced cross-sectional images in terms of tumour detection.

Material and methods

Twenty-three hepatocellular carcinoma patients undergoing RE treatment were scanned with DP-CBCT consisting of early arterial (EA) and late arterial (LA) phases before and after ⁹⁰Y administration. The CT-like datasets were compared according to embolisation effect, enhancement patterns, lesion detectability, image quality, and artifacts by two interventional radiologists blinded to each other. The compatibility of the two radiologists was evaluated with kappa statistical analysis, and the difference between EA and LA phases was evaluated with marginal homogeneity test. Also, DP-CBCT images were compared with preprocedural cross-sectional images (CT/MRI).

Results

For 23 patients 92 data were acquired. Thirteen patients showed a decrease on post-embolisation images both visually and on Hounsfield unit (HU) measurements. No statistical difference was found for tumour detection between EA and LA phases (p = 1.0). Tumour enhancement was visually superior at LA phases whereas EA phases were better for arterial mapping for selective catheterisation. DP-CBCT images were not inferior to preprocedural cross-sectional imaging findings.

Conclusions

DP-CBCT is a promising tool for predicting tumour response to therapy and is not inferior to preprocedural cross-sectional imaging in terms of tumour detection. It allows better assessment during RE procedures because early phases provide good mapping for superselective catheterisation whereas late phases are better for visualisation of tumour enhancement.

The clinical safety and efficacy of conventional transcatheter arterial chemoembolization and drug-eluting beads-transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma: A meta-analysis

Transcatheter arterial chemoembolization (TACE) plays an important role in the treatment of unresectable liver cancer. We conducted this meta-analysis to compare the clinical safety and efficacy of conventional TACE (C-TACE) and drug-eluting beads (DEB)-TACE. A search for those procedures was performed using the PubMed, EMBASE, and Cochrane Library databases. A meta-analysis of patients who underwent C-TACE or DEB-TACE was conducted. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Of 334 studies, 30 were analyzed. The complete response rate, disease control rate, objective response rate, 3-year survival rate, and non-response rate were significantly higher in patients who underwent DEB-TACE than those in patients who underwent C-TACE. The 1-year survival rate, 2-year survival rate, 30-day mortality rate, complete response rate, disease control rate, complete necrosis rate, non-response rate, objective response rate, progressive disease rate, and recurrence did not differ significantly between patients who underwent C-TACE and patients who underwent DEB-TACE. Patients who undergo DEB-TACE might have a higher complete response rate, disease control rate, and 3-year survival rate than patients who undergo C-TACE. Safety did not differ significantly between C-TACE and DEB-TACE.

Sequential dual-phase cone-beam CT is able to intra-procedurally predict the one-month treatment outcome of multi-focal HCC, in course of degradable starch microsphere TACE

OBJECTIVE

To evaluate the prognostic value of sequential dual-phase CBCT (DP-CBCT) imaging performed during degradable starch microsphere TACE (DSM-TACE) session in predicting the HCC's response to treatment, evaluate with modify response evaluation criteria in solid tumours (mRECIST) at 1-month multi-detector CT (MDCT) follow-up.

MATERIALS AND METHODS

Between January and May 2018, 24 patients (68.5 ± 8.5 year [45-85]) with HCC lesions (n = 96 [average 4/patient]) were prospectively enrolled. Imaging assessment included: pre-procedural MDCT, intra-procedural DP-CBCT performed before first and second DSM-TACEs and 1-month follow-up MDCT. Lesions' attenuation/pseudo-attenuation was defined as average value measured on ROIs (HU for MDCT; arbitrary unit called HU* for CBCT). Lesions' attenuation modification was correlated with the post-procedural mRECIST criteria at 1-month MDCT.

RESULTS

Eighty-two DSM-TACEs were performed. Lesion's attenuation values were: pre-procedural MDCT arterial phase (AP) 107.00 HU (CI 95% 100.00-115.49), venous phase (VP) 85.00 HU (CI 95% 81.13-91.74); and lesion's pseudo-attenuation were: first CBCT-AP 305.00 HU* (CI 95% 259.77-354.04), CBCT-VP 155.00 HU* (CI 95% 135.00-163.34). For second CBCT were: -AP 210.00 HU* (CI 95% 179.47-228.58), -VP 141.00 HU* (CI 95% 125.47-158.11); and for post-procedural MDCT were: -AP 95.00 HU (CI 95% 81.35-102.00), -VP 83.00 HU (CI 95% 78.00-88.00). ROC curve analysis showed that a higher difference pseudo-attenuation between first and second DP-CBCTs is related to treatment response. The optimal cut-off value of the difference between first and second CBCT-APs to predict complete response, objective response (complete + partial response) and overall disease control (objective response + stable disease) were > 206 HU* (sensitivity 80.0%, specificity 81.7%), > 72 HU* (sensitivity 79.5%, specificity 83.0%) and > - 7 HU* (sensitivity 91.6%, specificity 65.4%), respectively.

CONCLUSIONS

DP-CBCT can predict intra-procedurally, by assessing lesion pseudo-attenuation modification, the DSM-TACE 1-month treatment outcome.

Theranostics in Interventional Oncology: Versatile Carriers for Diagnosis and Targeted Image-Guided Minimally Invasive Procedures

We are continuously progressing in our understanding of cancer and other diseases and learned how they can be heterogeneous among patients. Therefore, there is an increasing need for accurate characterization of diseases at the molecular level. In parallel, medical imaging and image-guided therapies are rapidly developing fields with new interventions and procedures entering constantly in clinical practice. Theranostics, a relatively new branch of medicine, refers to procedures combining diagnosis and treatment, often based on patient and disease-specific features or molecular markers. Interventional oncology which is at the convergence point of diagnosis and treatment employs several methods related to theranostics to provide minimally invasive procedures tailored to the patient characteristics. The aim is to develop more personalized procedures able to identify cancer cells, selectively reach and treat them, and to assess drug delivery and uptake in real-time in order to perform adjustments in the treatment being delivered based on obtained procedure feedback and ultimately predict response. Here, we review several interventional oncology procedures referring to the field of theranostics, and describe innovative methods that are under development as well as future directions in the field.

Is dual-phase C-arm CBCT sufficiently accurate for the diagnosis of colorectal cancer liver metastasis during liver intra-arterial treatment?

PURPOSE

This study aimed to estimate the accuracy of dual-phase C-arm cone beam computed tomography (CBCT) for the detection of colorectal cancer liver metastases, as compared with multidetector computed tomography (MDCT).

MATERIALS AND METHODS

Between March 2014 and December 2016, 49 consecutive patients referred for intra-arterial treatment for colorectal cancer liver metastases were enrolled in a single-center observational study. All patients were examined with MDCT and with dual-phase C-arm cone beam computed tomography performed after iodine injection in the proper hepatic artery before intra-arterial treatment. Two blinded observers independently reviewed all examinations. Diagnostic accuracy was determined using both a six-cell matrix method and a "worst-case scenario."

RESULTS

Readers identified at MDCT 264 colorectal liver metastases and 43 other liver lesions. The early and late arterial phase showed 240 and 277 liver lesions respectively. A certainty of the diagnosis was obtained in 63% and 85% at the early (EAP) and late arterial phase (LAP), respectively. Streak artifacts or liver segment truncation, or inadequate enhancement was responsible for the inability to see or to correctly adjudicate a lesion to a diagnosis in 27% and 15% of the cases at the EAP and LAP. The "worst-case scenario" yielded a Se and Sp of 58% and 51%, respectively, at EAP and 84% and 70%, respectively, at LAP.

CONCLUSION

On CBCT, EAP showed limited accuracy. LAP provided the best tumor detectability.

KEY POINTS

• The early arterial phase (EAP) yielded poor accuracy: Se = 58% and Sp = 51% (p < 0.0001). • The late arterial phase (LAP) phase yielded good accuracy: Se = 84% and Se = 70% (p = 0.02). • The probability of a correct diagnosis at the EAP was 60%.

Visibility of Hypovascularized Liver Tumors during Intra-Arterial Therapy Using Split-Bolus Single-Phase Cone Beam CT

PURPOSE

To validate a split-bolus contrast injection protocol for single-phase CBCT in terms of detectability of hypovascular liver tumors compared to digital subtraction angiography (DSA).

MATERIALS AND METHODS

In this retrospective, single-center study, 20 consecutive patients with in total 77 hypovascularized tumors referred for intra-arterial therapy received a split-bolus single-phase CBCT. Two readers rated the visibility of the target tumors scheduled for embolization in CBCT and DSA compared to the pre-interventional multiphasic CT or MRI used as reference on a 3-point scoring system (1 = optimal, 3 = not visible) and catheter-associated artifacts (1 = none, 3 = extended). SNR, CNR and contrast values were derived from 37 target tumors in CBCT and MRI. Statistical analysis included the kappa test to determine interrater reliability, the Friedman's test for the inter-modality comparison evaluating tumor visibility in DSA and CBCT as well as for quantitative assessment. Post hoc analysis included the Wilcoxon signed-rank test. p values < 0.05 were considered significant.

RESULTS

Ninety percentage of target tumors were rated as visible in CBCT and 37.5% in DSA (p < 0.001). 70.1% of pre-interventionally detected hypovascularized tumors were depicted with CBCT and 31.2% by DSA (p < 0.001). 7.8% of known tumors were outside the FOV. Quantitative assessment showed higher image contrasts in CBCT (1.91 ± 7.01) compared to hepatobiliary-phase MRI (0.29 ± 0.14, p = 0.003) and to portal-venous (p.v.) MRI (0.31 ± 0.13, p < 0.001), but higher CNR for MRI (1.18 ± 0.80; 13.92 ± 15.82; 13.79 ± 6.65).

CONCLUSION

In conclusion, the split-bolus single-phase CBCT detects significantly more hypovascularized liver tumors compared to DSA performed through the proper hepatic artery with high image contrasts.

LEVEL OF EVIDENCE

Level III, diagnostic study.