The Efficacy of Cone-Beam CT–Based Liver Perfusion Mapping to Predict Initial Response of Hepatocellular Carcinoma to Transarterial Chemoembolization

Model-based perfusion reconstruction with time separation technique in cone-beam CT dynamic liver perfusion imaging

BACKGROUND

The success of embolization, a minimally invasive treatment of liver cancer, could be evaluated in the operational room with cone-beam CT by acquiring a dynamic perfusion scan to inspect the contrast agent flow.

PURPOSE

The reconstruction algorithm must address the issues of low temporal sampling and higher noise levels inherent in cone-beam CT systems, compared to conventional CT.

METHODS

Therefore, a model-based perfusion reconstruction based on the time separation technique (TST) was applied. TST uses basis functions to model time attenuation curves. These functions are either analytical or based on prior knowledge (PK), extracted using singular value decomposition of the classical CT perfusion data of animal subjects. To explore how well the PK can model perfusion dynamics and what the potential limitations are, the dynamic cone-beam CT (CBCT) perfusion scan was simulated from a dynamic CT perfusion scan under different noise levels. The TST method was compared to static reconstruction.

RESULTS

It was demonstrated on this simulated dynamic CBCT perfusion scan that a set consisting of only four basis functions results in perfusion maps that preserve relevant information, denoise the data, and outperform static reconstruction under higher noise levels. TST with PK would not only outperform static reconstruction but also the TST with analytical basis functions. Furthermore, it has been shown that only eight CBCT rotations, unlike previously assumed ten, are sufficient to obtain the perfusion maps comparable to the reference CT perfusion maps. This contributes to saving dose and reconstruction time. The real dynamic CBCT perfusion scan, reconstructed under the same conditions as the simulated scan, shows potential for maintaining the accuracy of the perfusion maps. By visual inspection, the embolized region was matching to that in corresponding CT perfusion maps.

CONCLUSIONS

CBCT reconstruction of perfusion scan data using the TST method has shown promising potential, outperforming static reconstructions and potentially saving dose by reducing the necessary number of acquisition sweeps. Further analysis of a larger cohort of patient data is needed to draw final conclusions regarding the expected advantages of the TST.

Application of Cone-beam Computed Tomography in Interventional Therapies for Liver Malignancy: A Consensus Statement by the Chinese College of Interventionalists

Despite its crucial role in interventional therapies for liver malignancy, cone-beam computed tomography (CBCT) has not yet been fully integrated into clinical practice due to several complicating factors, including nonstandardized operations and limited recognition of CBCT among interventional radiologists. In response, the Chinese College of Interventionalists has released a consensus statement aimed at standardizing and promoting the application of CBCT in the interventional therapies for liver malignancy. This statement summarizes CBCT scanning techniques, and operational standards, and highlights its potential applications in clinical practice.

Baseline parenchymal blood volume is a potential prognostic imaging biomarker in patients with malignant liver tumors treated with transarterial chemoembolization

PURPOSE

To assess the prognostic value of Parenchymal Blood Volume (PBV) in predicting survival, tumor response, and PBV response after transarterial chemoembolization (TACE).

METHODS

A total of 137 patients with malignant liver tumors who were treated with TACE between 07/2016 and 07/2018 were evaluated. Computed tomography illustrations were reworked at a dedicated workstation to create a PBV map which was overlapped with the associated magnetic resonance image to determine tumor diameter and PBV. Patients were divided into two groups according to their initial PBV value: PBV < 50 or ≥ 50 ml/l.

RESULTS

Retrospectively, for patients with at least 2 TACE and initial PBV < 50 ml/l (n = 27), the tumor volume, regardless of the primary tumor type, decreased by 13.26%, and PBV showed a decrease of 23.11%. For 84 patients with PBV ≥ 50 ml/l, the tumor volume decreased by 24.01%, and PBV showed a more substantial decrease of 44.69% (both p < 0.001). In the overall study population (n = 137), patients with an initial PBV ≥ 50 ml/l (n = 101) survived for an average of 15.05 months, while patients with an initial PBV < 50 ml/l (n = 36) survived for 10.01 months (p < 0.002). Subgroup analysis indicated that median survival in the HCC group was longer at PBV ≥ 50 ml/l. For CRC and other primary tumors, the survival time for high and low initial PBV was almost identical.

CONCLUSION

Our study reveals a noteworthy correlation between high initial PBV values and a significant reduction in both relative and absolute tumor volume. This association suggests a potential prognostic indicator, indicating that elevated PBV may signify a more favorable response to transarterial chemoembolization (TACE). Additionally, patients with high initial PBV values experienced an extended overall survival time. Notably, the subgroup analysis highlighted a prolonged survival time in the HCC group with elevated initial PBV values. These findings underscore the potential significance of assessing PBV as a predictive factor in the context of TACE, especially in specific tumor entities such as HCC. Further investigations are essential to validate and extrapolate these observations to optimize patient outcomes.

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.

Transcatheter Arterial Chemoembolization Combined with Simultaneous Cone-beam Computed Tomography-guided Microwave Ablation in the Treatment of Small Hepatocellular Carcinoma: Clinical Experiences From 50 Procedures

RATIONALE AND OBJECTIVES

To investigate the technical success, safety and outcomes of transcatheter arterial chemoembolization (TACE) combined with simultaneous cone-beam computed tomography (CBCT)-guided microwave ablation (MWA) in small hepatocellular carcinoma (SHCC).

MATERIALS AND METHODS

Retrospective analysis of 66 lesions in 50 patients (38 men, 12 women) who underwent TACE combined with simultaneous CBCT-guided MWA for SHCC. After 1 month of treatment, the tumor responses were assessed using the mRECIST criteria, along with interventional-related complications and changes in hepatic and renal function. Moreover, progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

All patients achieved technical success. The mean target tumor size was 3.4 ± 0.7 (range, 2.2-4.9) cm. The mean energy, ablation duration per tumor, and the mean safety margin were 51.3  ±  8.4  kJ, 6.7  ±  0.8  minutes and 1.4 ± 0.6 cm, respectively. The 1-, 3-, and 5-year PFS rates were 90.0%, 65.4%, and 35.7%, respectively, with a mean PFS of 43.46 months; and the 1-, 3-, and 5-year OS rates were 98.0%, 89.8%, and 74.3%, respectively, with a mean OS of 54.90 months. Multivariate Cox regression analysis further illustrated that TACE combined with MWA in the treatment of a single tumor with a diameter of less than 3 cm was an independent protective factor for PFS and OS (p < 0.001). The patients had no major complications. Among the exceptions, one patient (2%) had an asymptomatic perihepatic effusion that resolved spontaneously, two patients (4%) developed massive right pleural effusion, requiring thoracic drainage, and another patient (2%) developed a hepatic subcapsular hemorrhage required interventional embolization.

CONCLUSION

CBCT-guided TACE combined with simultaneous MWA was a safe and successful treatment of SHCC with a high technical efficacy.

Making timely remedial measures after TACE based on the results of cone-beam CT liver perfusion

OBJECTIVE

To evaluate the feasibility and safety of using cone-beam CT (CBCT) to measure changes in parenchymal blood volume (PBV) of patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) and to guide microwave ablation (MWA) for residual tumors.

METHODS

A retrospective study was performed on 42 patients with HCC who completed TACE and received CBCT-guided perfusion imaging. The residual active lesions after TACE were supplemented with MWA to complete the treatment process according to the residual PBV. The outcomes were analyzed, including PBV changes, interventional-related complications, local tumor progression (LTP) and overall survival (OS).

RESULTS

Technical success was achieved in all lesions. Correlation analysis revealed that greater volume of residual PBV after MWA is negatively correlated with LTP. (p = .000); and the decrease of PBV was positively correlated with LTP (p = .000). All adverse events and complications were CTCAE Grade 1/2. After combination treatment, the 1-, 3-, and 5-year LTP-free survival were 97.6%, 69.0% and 15.1%, respectively, with a median LTP of 49.0 months (95% CI:43.129,54.871). Multivariate Cox regression revealed that the residual PBV > 13 ml/1000 was an independent factor predicting a shorter OS and LTP (Both p< .05). For LTP, multivariate Cox regression showed that a tumor in a single lesion were independently predicted to have a longer LTP in patients with HCC (p = .033).

CONCLUSION

CBCT is feasible and safe to use to measure changes in the PBV before and after TACE treatment, while it can also guide MWA for the treatment of residual tumors in one session.

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.

Role of Cone-Beam CT in the Intraprocedural Evaluation of Chemoembolization of Hepatocellular Carcinoma

Purpose

To assess the ability of Cone-Beam CT (CBCT), performed during the Transcatheter Arterial Chemoembolization (TACE), in predicting the response to treatment of hepatocellular carcinoma (HCC).

Materials and Methods

We evaluated fifty patients (M/F = 40/10, mean age: 66.7 years ± 8.22) with hepatocellular carcinoma (HCC), for a total of 82 nodules evaluated (mean diameter: 21.4 ± 11 mm). All patients performed a CT scan one month before and one month after TACE. After TACE is completed, a CBCT was performed to assess the degree of drug retention in the lesions. For each lesion, the major diameter, volume, and density of the vital portion were evaluated. The response to TACE was assessed using the mRECIST criteria on the CT scan carried out one month after the procedure. The receiver operating characteristic (ROC) curves were performed to assess the accuracy of the CBCT in predicting the response to treatment and to identify the cut-off points for each parameter under examination.

Results

A complete response (CR) was observed in 24/50 patients (48%), a partial response (PR) in 16/50 (32%), stable disease (SD) in 8/50 (16%), and progressive disease (PD) in 2/50 (4%). Evaluation of the area under the ROC curve showed that the diameter, volume, and density of the lesion, measured with CBTC, had an accuracy of 94%, 96%, and 98%, respectively, in discriminating a complete response from a not complete response.

Conclusion

CBCT is effective in predicting short-term response at 1-month follow-up of HCC treated by chemoembolization.

The Efficacy of Cone-Beam CT-Based Perfusion Mapping in Evaluation of Tissue Perfusion in Peripheral Arterial Disease

This study investigated the use of cone-beam computed tomography (CBCT)-based perfusion mapping during percutaneous transluminal angioplasty (PTA) to predict clinical outcome in the peripheral arterial disease (PAD). From January 2016 to March 2020, 43 patients (28 male, 15 female; mean age, 69) with 51 limbs, who underwent PTA with CBCT-based foot perfusion mapping for PAD were included. Parenchymal blood volume (PBV) of foot was measured. Clinical response was investigated based on medical records. Predictive value for clinical success was evaluated using multiple logistic regression with C-statistics. Two reviewers visually assessed the improvement on angiography and CBCT-based foot perfusion mapping; inter-observer agreement of clinical success between the two were measured. Technical and clinical success rate of PTA was 90.8% and 68.6%, respectively. In multiple logistic regression, the maximum value of PBV (PBV_max) on perfusion mapping after PTA was significant (p = 0.03) for evaluating clinical success with the highest C-statistic (0.84). Using a cutoff of 235.7 mL/L for PBV_max after PTA, area under curve for prediction of clinical success was 0.664, and sensitivity and specificity were 71.4% and 68.8%, respectively. Consistency in prediction of clinical success between the two reviewers was almost perfect for CBCT-based foot perfusion mapping.

Usefulness of Cone-Beam CT-Based Liver Perfusion Mapping for Evaluating the Response of Hepatocellular Carcinoma to Conventional Transarterial Chemoembolization

We investigated the cone beam computed tomography (CBCT)-based-liver-perfusion-mapping usefulness during transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) to access treatment response and predict outcomes. From October 2016 to September 2018, 42 patients with HCCs scheduled for conventional TACE were prospectively enrolled. Three reviewers evaluated the unenhanced and contrast-enhanced CBCT and CBCT-based-liver-perfusion-mapping of each tumor. Parenchymal blood volume (PBV) was measured. The operator’s judgment on the technical results was recorded. Response outcome was determined on follow-up CT or magnetic resonance imaging, according to the modified Response Evaluation Criteria in Solid Tumors. Diagnostic performance for detection of a viable tumor was evaluated using multiple logistic regression with C-statistics. CBCT-based-liver-perfusion-mapping and the maximum PBV of the tumor were significant in multiple logistic regression analysis of response (p < 0.0001, p = 0.0448, respectively), with C-statistics of 0.9540 and 0.7484, respectively. Diagnostic accuracy of operator’s judgment was 79.66% (95%CI 69.39%–89.93%). Diagnostic performance of CBCT-based-liver-perfusion-mapping showed a high concordance in three reviewers. The mean PBV of tumor, maximum PBV of tumor, and mean PBV of liver significantly decreased after TACE (each p < 0.001). In ROC curve analysis, the AUC for prediction of residual tumor by the maximum PBV of tumor after TACE was 0.7523, with 80.8% sensitivity and 60.6% specificity.

Imaging-based characterization of convective tissue properties

Convective transport is an important phenomenon for nanomedicine delivery. We present an imaging-based approach to recover tissue properties that are significant in the accumulation of nanoparticles delivered via systemic methods. The classical pharmacokinetic analysis develops governing equations for the particle transport from a first principle mass balance. Fundamentally, the governing equations for compartmental mass balance represent a spatially invariant mass transport between compartments and do not capture spatially variant convection phenomena. Further, the parameters recovered from this approach do not necessarily have direct meaning with respect to the governing equations for convective transport. In our approach, a framework is presented for directly measuring permeability in the sense of Darcy flow through porous tissue. Measurements from our approach are compared to an extended Tofts model as a control. We demonstrate that a pixel-wise iterative clustering algorithm may be applied to reduce the parameter space of the measurements. We show that measurements obtained from our approach are correlated with measurements obtained from the extended Tofts model control. These correlations demonstrate that the proposed approach contains similar information to an established compartmental model and may be useful in providing an alternative theoretical framework for parameterizing mathematical models for treatment planning and diagnostic studies involving nanomedicine where convection dominated effects are important.

Quantitative Assessment of the Hemodynamic Effects of Intra-Arterial Nitroglycerin on Hepatocellular Carcinoma using Two-Dimensional Perfusion Angiography

PURPOSE

To determine the hemodynamic effects of intra-arterial nitroglycerin on hepatocellular carcinoma (HCC) using 2-dimensional (2D) perfusion angiography.

MATERIALS AND METHODS

Two-dimensional perfusion angiograms obtained prior to radioembolization from September 2019 to February 2020 were retrospectively reviewed. The inclusion criteria were the presence of Liver Imaging Reporting and Data System-5 tumors and angiographically distinguishable tumor and background liver. The exclusion criteria were previously treated tumors and motion-degraded studies. Thirteen patients with 2D perfusion angiograms obtained before and 2 minutes ± 1 after the administration of intra-arterial nitroglycerin were analyzed. The mean patient age was 72 years ± 9 and 11 of 13 (85%) had cirrhosis. The mean maximum tumor dimension was 4.6 cm ± 2.1. Eight tumors were in the right lobe and 5 were in the left lobe. The tumor and background liver 2D perfusion data were processed and the areas under the time-density curves were calculated. The relative perfusion of HCC to background liver was compared before and after nitroglycerin administration using a 2-tailed paired t-test.

RESULTS

The mean rate of contrast administration was 1.4 mL/s ± 0.7 and the mean volume administered was 7.1 mL ± 3.3. The mean nitroglycerin dose was 281 μg ± 69. Ten of 13 patients (77%) demonstrated a relative increase in tumor perfusion. The mean HCC to background liver area under the curve ratio was 1.94 ± 0.76 before and 2.40 ± 0.89 after nitroglycerin administration (P < .05).

CONCLUSIONS

Intra-arterial nitroglycerin increases previously untreated HCC perfusion relative to background liver as measured by 2D perfusion angiography, but this effect is variable among patients and should be validated with 3-dimensional imaging techniques.

Use of perfusional CBCT imaging for intraprocedural evaluation of endovascular treatment in patients with diabetic foot: a concept paper

Diabetes mellitus (DM) is one of the most common metabolic diseases worldwide; its global burden has increased rapidly over the past decade, enough to be considered a public health emergency in many countries. Diabetic foot disease and, particularly diabetic foot ulceration, is the major complication of DM: through a skin damage of the foot, with a loss of epithelial tissue, it can deepen to muscles and bones and lead to the amputation of the lower limbs. Peripheral arterial disease (PAD) in patients with diabetes, manifests like a diffuse macroangiopathic multi-segmental involvement of the lower limb vessels, also connected to a damage of collateral circulation; it may also display characteristic microaneurysms and tortuosity in distal arteries. As validation method, Bold-MRI is used. The diabetic foot should be handled with a multidisciplinary team approach, as its management requires systemic and localized treatments, pain control, monitoring of cardiovascular risk factors and other comorbidities. CBCT is an emerging medical imaging technique with the original feature of divergent radiation, forming a cone, in contrast with the spiral slicing of conventional CT, and has become increasingly important in treatment planning and diagnosis: from small anatomical areas, such as implantology, to the world of interventional radiology, with a wide range of applications: as guidance for biopsies or ablation treatments. The aim of this project is to evaluate the usefulness of perfusion CBCT imaging, obtained during endovascular revascularization, for intraprocedural evaluation of endovascular treatment in patients with diabetic foot. (www.actabiomedica.it).

The value of intra-procedural transcatheter intraarterial contrast-enhanced ultrasonography (IA-CEUS) in predicting the short-term efficacy of conventional transarterial chemoembolization (cTACE)

BACKGROUND

This study aimed to evaluate whether corona enhancement and intratumor perfusion features of intra-procedural transcatheter intraarterial contrast-enhanced ultrasonography (IA-CEUS) predict short-term tumor response on follow-up contrast-enhanced magnetic resonance imaging (CE-MRI) in patients with hepatocellular carcinoma (HCC) treated with conventional transarterial chemoembolization (cTACE).

METHODS

This trial included 39 patients with 51 HCC target lesions who underwent cTACE with IA-CEUS. The maximum cross-sectional area ratio of intratumor perfusion between pre- and post-procedure, as well as the peak value and sickness of corona enhancement immediately post-cTACE were measured respectively. Tumor response at MRI was assessed according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) guidelines. Nonparametric Spearman rank-order correlation was used to correlate the maximum cross-sectional area ratio of intratumor perfusion, the peak value, and sickness of corona enhancement of IA-CEUS immediately after cTACE with tumor response.

RESULTS

The results showed that 39 patients with 51 target lesions were assessed for tumor response. Complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD) were 22 (43.1%), 14 (27.5%), 10 (19.6%), and 5 (9.8%), respectively. The maximum cross-sectional area ratio of intratumor perfusion moderately correlated with tumor response on CE-MRI (Spearman rho =0.513, P<0.001). Furthermore, the peak value and sickness of corona enhancement showed a good correlation with tumor response on CE-MRI respectively (Spearman rho =0.671, P<0.001, rho =0.704, P<0.001).

CONCLUSIONS

Intra-procedural transcatheter IA-CEUS may predict short-term tumor response in cTACE of HCC. The feature of corona enhancement immediately post-cTACE also showed a more accurate prediction when compared with the feature of intratumor infusion (rho =0.671).