The usefulness of contrast-enhanced ultrasonography in the early detection of hepatocellular carcinoma viability after transarterial chemoembolization: pilot study

Accuracy of Contrast-Enhanced Ultrasound for Hepatocellular Carcinoma Post-Transcatheter Arterial Embolization

Background/Objectives: Contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technique with similar accuracy to CT and MRI for the diagnosis of hepatocellular carcinoma (HCC). CEUS offers several advantages in patient populations who have contraindications for CT or MRI. There are limited prospective studies in the United States evaluating the diagnostic equivalence of CEUS following transcatheter arterial chemoembolization (TACE) with same-day CT/MRI. This prospective pilot study compared CEUS and CT/MRI in patients with HCC following TACE in a United States population using Lumason® contrast agent and the Liver Reporting and Data System (LI-RADS). Methods: Following institutional review board protocols, adult patients with a diagnosis of HCC were included. Follow-up CT/MRI was directed by referring clinicians, and CEUS was performed on the same day. CEUS was used to evaluate for treated lesion(s), new lesion(s), and portal vein thrombus before and after Lumason®. Any subsequent follow-up imaging was reviewed. Results: In 26 enrolled patients, 33 target lesions were identified (size range 0.9-16.8 cm), and 26 were LI-RADS-5 or -M. CEUS identified 19 cases of residual tumor, 12 with no viable disease; CT/MRI identified 17 cases of residual tumor, 16 with no viable disease (p = 0.617). Both CEUS and CT/MRI identified five portal vein thrombi. Two lesions were missed or miscategorized on CEUS, while six were missed or miscategorized on CT/MRI (p = 0.289). Six new lesions were identified on both CEUS and CT/MRI. Of these new lesions, four were identified only by CT/MRI and three only by CEUS. Conclusions: CEUS is comparable to CT/MRI performed at identical follow-up intervals in evaluating for residual versus treated HCC following first-time TACE.

Diagnostic values of contrast-enhanced MRI and contrast-enhanced CT for evaluating the response of hepatocellular carcinoma after transarterial chemoembolisation: a meta-analysis

OBJECTIVES

To assess and compare the diagnostic value of contrast-enhanced MRI (CEMRI) and contrast-enhanced CT (CECT) for evaluating the response of hepatocellular carcinoma (HCC) after transarterial chemoembolisation (TACE).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, the Cochrane Library, CNKI and Wanfang databases were systematically searched from inception to 1 August 2023.

ELIGIBILITY CRITERIA

Studies with any outcome that demonstrates the diagnostic performance of CEMRI and CECT for HCC after TACE were included.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted the data and assessed the quality of included studies. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. The diagnostic performance of CEMRI and CECT for the response of HCC was investigated by collecting true and false positives, true and false negatives, or transformed-derived data from each study to calculate specificity and sensitivity. Other outcomes are the positive likelihood ratio/negative likelihood ratio (NLR), the area under the receiver operating characteristic curve (AUC) for diagnostic tests and the diagnostic OR (DOR). Findings were summarised and synthesised qualitatively according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

This study included 5843 HCC patients diagnosed with CEMRI or CECT and treated with TACE from 36 studies. The mean proportion of men in the total sample was 76.3%. The pool sensitivity, specificity and AUC of CEMRI in diagnosing HCC after TACE were 0.92 (95% CI: 0.86 to 0.96), 0.94 (95% CI: 0.86 to 0.98) and 0.98 (95% CI: 0.96 to 0.99). The pool sensitivity, specificity and AUC of CECT in diagnosing HCC after TACE were 0.74 (95% CI: 0.68 to 0.80), 0.98 (95% CI: 0.93 to 1.00) and 0.90 (95% CI: 0.88 to 0.93).

CONCLUSIONS

In conclusion, this study found that both CEMRI and CECT had relatively high predictive power for assessing the response of HCC after TACE. Furthermore, the diagnostic value of CEMRI may be superior to CECT in terms of sensitivity, AUC, DOR and NLR.

Contrast-enhanced US Evaluation of Hepatocellular Carcinoma Response to Chemoembolization: A Prospective Multicenter Trial

Background Contrast-enhanced (CE) US has been studied for use in the detection of residual viable hepatocellular carcinoma (HCC) after locoregional therapy, but multicenter data are lacking. Purpose To compare two-dimensional (2D) and three-dimensional (3D) CE US diagnostic performance with that of CE MRI or CT, the current clinical standard, in the detection of residual viable HCC after transarterial chemoembolization (TACE) in a prospective multicenter trial. Materials and Methods Participants aged at least 21 years with US-visible HCC scheduled for TACE were consecutively enrolled at one of three participating academic medical centers from May 2016 to March 2022. Each underwent baseline 2D and 3D CE US before TACE, 2D and 3D CE US 1-2 weeks and/or 4-6 weeks after TACE, and CE MRI or CT 4-6 weeks after TACE. CE US and CE MRI or CT were evaluated by three fellowship-trained radiologists for the presence or absence of viable tumors and were compared with reference standards of pathology (18%), angiography on re-treatment after identification of residual disease at 1-2-month follow-up imaging (31%), 4-8-month CE MRI or CT (42%), or short-term (approximately 1-2 months) CE MRI or CT if clinically decompensated and estimated viability was greater than 50% at imaging (9%). Diagnostic performance criteria, including sensitivity and specificity, were obtained for each modality and time point with generalized estimating equation analysis. Results A total of 132 participants were included (mean age, 64 years ± 7 [SD], 87 male). Sensitivity of 2D CE US 4-6 weeks after TACE was 91% (95% CI: 84, 95), which was higher than that of CE MRI or CT (68%; 95% CI: 58, 76; P < .001). Sensitivity of 3D CE US 4-6 weeks after TACE was 89% (95% CI: 81, 94), which was higher than that of CE MRI or CT (P < .001), with no evidence of a difference from 2D CE US (P = .22). CE MRI or CT had 85% (95% CI: 76, 91) specificity, higher than that of 4-6-week 2D and 3D CE US (70% [95% CI: 56, 80] and 67% [95% CI: 53, 78], respectively; P = .046 and P = .023, respectively). No evidence of differences in any diagnostic criteria were observed between 1-2-week and 4-6-week 2D CE US (P > .21). Conclusion The 2D and 3D CE US examinations 4-6 weeks after TACE revealed higher sensitivity in the detection of residual HCC than CE MRI or CT, albeit with lower specificity. Importantly, CE US performance was independent of follow-up time. Clinical trial registration no. NCT02764801 © RSNA, 2023 Supplemental material is available for this article.

The feasibility of early response evaluation using superb microvascular imaging one day after transcatheter arterial chemoembolization for hepatocellular carcinoma

PURPOSE

The purpose of this study was to determine the feasibility of early Superb microvascular imaging (SMI) for prediction of the effect of HCC treatment after transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

A total of 96 HCCs (70 patients) treated with TACE between September 2021 and May 2022 were included in this study. SMI, Color Doppler imaging (CDI), and Power Doppler imaging (PDI) were performed the day after TACE for evaluation of intratumoral vascularity of the lesion using an Aplio500 ultrasound scanner (Toshiba Medical Systems, Corporation, Tochigi, Japan). Grading of the vascular presence was performed using a five-point scale. A dynamic CT image taken after 29-42 days was used for comparison of sensitivity, specificity, and accuracy for detection of tumor vascularity between SMI, CDI, and PDI. Univariate and multivariate analysis were performed for assessment of factors affecting intratumoral vascularity.

RESULTS

Fifty-eight lesions (60%) showed complete remission (CR) and 38 lesions (40%) showed partial response (PR) or no response at 29-42 days on Multi-detector Computed Tomography (MDCT) after TACE. SMI showed sensitivity of 86.84% for detection of intratumoral flow, which was significantly higher compared with that of CDI (10.53%, p < 0.001) and PDI (36.84%, p < 0.001). The results of multivariate analysis indicated that tumor size was a significant factor in detection of blood flow using the SMI technique.

CONCLUSION

Early SMI may be utilized as an adjunctive diagnostic test for evaluation of treated lesions after TACE, particularly when the location of the tumor is in an area of the liver where a suitable sonic window can be identified.

Loco-regional treatment of hepatocellular carcinoma: Role of contrast-enhanced ultrasonography

Hepatocellular carcinoma (HCC) is one of the few cancers for which locoregional treatments (LRTs) are included in international guidelines and are considered as a valid alternative to conventional surgery. According to Barcelona Clinic Liver Cancer classification, percutaneous treatments such as percutaneous ethanol injection, radiofrequency ablation and microwave ablation are the therapy of choice among curative treatments in patients categorized as very early and early stage, while transcatheter arterial chemoembolization is considered the better option for intermediate stage HCC. A precise assessment of treatment efficacy and surveillance is essential to optimize survival rate, whereas residual tumor requires additional treatment. Imaging modalities play a key role in this task. Currently, contrast-enhanced computed tomography/magnetic resonance imaging are considered the standard imaging modalities for this purpose. Contrast enhanced ultrasound (CEUS), using second generation contrast agents, plays an increasingly important role in detecting residual disease after LRTs. CEUS is a straightforward to perform, repeatable and cost-effective imaging modality for patients with renal failure or iodine allergies. Due to the ability to focus on single regions, CEUS can also provide high temporal resolution. Moreover, several studies have reported the same or better diagnostic accuracy as contrast-enhanced computed tomography for assessing tumor vascularity 1 mo after LRTs, and recently three-dimensional (3D)-CEUS has been reported as a promising technique to improve the evaluation of tumor response to therapy. Furthermore, CEUS could be used early after procedures in monitoring HCC treatments, but nowadays this indication is still debated, and data from literature are conflicting, especially after transcatheter arterial chemoembolization procedure.

Comparative the clinical value of contrast-enhanced ultrasonography, enhancement CT and MRI for diagnosing of liver lesions

BACKGROUND

To investigate the accuracy of contrast-enhanced ultrasonography, CT-enhancement and MRI in the diagnosis of liver-occupying lesions.

METHODS

176 patients with suspected liver lesions in our hospital were retrospectively studied from July 2014 to July 2016. All of the 176 patients were diagnosed by contrast-enhanced ultrasonography, enhanced CT and MRI, and the pathological examination was performed. The results of pathological examination were regarded as the results of the diagnosis. The diagnostic accuracywas then compared among contrast-enhanced ultrasound, enhanced CT and MRI of these patients.

RESULTS

The results of contrast-enhanced ultrasonography showed that 164 of the 176 patients had liver-occupying lesions, and the accuracy of the diagnosis was 95.35%, which was significantly higher than that of CT enhancement and MRI (80.23% 84.30%). The accuracy of contrast-enhanced ultrasonography, in the diagnosis of primary liver cancer was significantly higher than that of CT enhancement and MRI (P <  0.05), and the difference was significant difference (P <  0.05).

CONCLUSIONS

The examination of contrast-enhanced ultrasonography is relatively simple, and the patients can get duplicateexamination, so we should choose the contrast-enhanced ultrasonography as the preferred method of diagnosis in liver mass, especially primary liver cancer.

Intraarterial contrast-enhanced ultrasound to predict the short-term tumour response of hepatocellular carcinoma to Transarterial chemoembolization with Lipiodol

BACKGROUND

Transarterial chemoembolization (TACE) is an effective locoregional therapy in hepatocellular carcinoma (HCC). However, it is difficult to predict the tumour response (TR) of TACE intraprocedurally. The aim of this study was to predict the TR after TACE (1-3 months) in HCC patients using intraprocedural intraarterial contrast enhanced ultrasound (IA-CEUS).

METHODS

In this case-control study, consecutive patients who received TACE in our hospital from September 2018 to May 2019 were enrolled. IA-CEUS was performed before and after TACE. Postoperative contrast-enhanced liver MRI was performed 1-3 months after TACE as the gold standard. According to the modified Response Evaluation Criteria in Solid Tumours (mRECIST), ultrasonic manifestations were compared between the complete remission (CR) group and non-CR group by univariate and multivariate analyses. A logistic predictive model was established and validated, and its diagnostic efficiency was evaluated.

RESULTS

Forty-four patients with sixty-one lesions were enrolled in the study. Multivariate analysis identified, the risk factors as a large lesion diameter (OR: 1.84; 95% confidence interval [CI]: 1.009, 3.080; P = 0.020), a larger dimension of non-enhancing area in superior mesenteric artery (SMA)-CEUS than the size in B-mode ultrasound preoperatively (OR: 3.379; 95% CI: 1.346,8.484; P = 0.010), presence of corona enhancement in hepatic artery (HA)-CEUS postoperatively (OR: 6.642; 95% CI: 1.214, 36.331; P = 0.029), and decreased corona enhancement thickness (per centimetre) postoperatively (OR: 0.025; 95% CI: 0.006,0.718; P = 0.025). The area under the receiver operating characteristic curve (AUROC) of the predictive model was 0.904 (95% CI: 0.804, 0.966; P < 0.001). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 81.08, 91.67, 85.25, 93.75, and 75.86%, respectively. Leave-one-out cross-validation (LOOCV) showed that the accuracy was 77.05%.

CONCLUSIONS

Intraprocedural IA-CEUS can be used to predict the TR in HCC patients after TACE.

Meta-analysis and systematic review of contrast-enhanced ultrasound in evaluating the treatment response after locoregional therapy of hepatocellular carcinoma

PURPOSE

Contrast-enhanced ultrasound (CEUS) is a useful tool to assess treatment response after percutaneous ablation or transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Here, we performed a systematic review and meta-analysis to evaluate the usefulness of CEUS in identifying residual tumor after locoregional therapy.

METHODS

PubMed, Scopus, and Cochrane library databases were searched from their inception until March 8, 2021, for diagnostic test accuracy studies comparing CEUS to a reference standard for identifying residual tumors after locoregional therapy of HCC. The pooled sensitivity, specificity, accuracy, and diagnostic odds ratio (DOR) were obtained using a bivariate random effects model. Subgroup analyses were performed by stratifying the studies based on study design, type of locoregional therapy, CEUS criteria for residual tumor, timing of CEUS follow up, and type of standard reference.

RESULTS

Two reviewers independently evaluated 1479 publications. After full-text review, 142 studies were found to be relevant, and 43 publications (50 cohorts) were finally included. The overall sensitivity of CEUS in detection of residual disease estimated from the bivariate random effects model was 0.85 (95% CI 0.80-0.89). Similarly, the overall specificity was 0.94 (95% CI 0.91-0.96). The diagnostic accuracy was 93.5%. The DOR was 70.1 (95% CI 62.2-148), and the AUROC was 0.95. Importantly, subgroup analysis showed no apparent differences in the diagnostic performance between locoregional therapy (TACE vs. ablation) and criteria used to define residual enhancement, timing of performing CEUS, study design, or type of reference standard.

CONCLUSION

CEUS is a highly accurate method to identify HCC residual tumor after TACE or percutaneous ablation.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ^©RSNA, 2020.

Early evaluation of treatment response to transarterial chemoembolization in patients with advanced hepatocellular carcinoma: The role of dynamic three-dimensional contrast-enhanced ultrasound

BACKGROUND

Dynamic three-dimensional contrast-enhanced ultrasound (3D-CEUS) with quantitative analysis is available in recent years. It can reduce the quantitative sampling error caused by the inconsistency of different sections in order to evaluate local treatment response of hepatocellular carcinoma (HCC) accurately.

OBJECTIVE

To investigate the value of dynamic 3D-CEUS in evaluating the early response to transarterial chemoembolization (TACE) treatment in patients with advanced HCC lesions.

METHODS

In this prospective study, both two-dimensional (2D) CEUS and dynamic 3D-CEUS were performed on 40 HCC patients who scheduled for TACE at baseline (T0) and 1-3 days (T1) after treatment. Tumor microvascular perfusion changes were assessed by CEUS time-intensity curve (TIC) and quantitative parameters. According to contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging 1 month after treatment results, patients were divided into responders and non-responders groups. The changes of perfusion parameters of both 2D-CEUS and 3D-CEUS were compared between responders and non-responders groups before and after TACE treatment.

RESULTS

Before and after TACE treatment, no significant difference in maximum diameter of HCC lesions between the two groups could be found. There were more significant differences and ratios of perfusion parameters in 3D-CEUS quantitative analysis than in 2D-CEUS. The mutual significant differences and ratios of 2D-CEUS and 3D-CEUS included peak intensity (PI) difference, PI ratio, ratio of area under the curve (A), ratio of area under the wash-out part (AWO) and slope (S) difference. The former 4 corresponding parameters were better on 3D-CEUS than on 2D-CEUS.

CONCLUSION

Dynamic 3D-CEUS can be used as a potential imaging method to evaluate early treatment response to TACE in advanced HCC patients.

Utility of Contrast-Enhanced Ultrasound for Early Therapeutic Evaluation of Hepatocellular Carcinoma After Transcatheter Arterial Chemoembolization

OBJECTIVES

We aimed to investigate whether contrast-enhanced ultrasound (CEUS) could be useful for early evaluation of the treatment response to transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC).

METHODS

This study retrospectively selected HCCs in which homogeneous retention of iodized oil was confirmed on non-contrast-enhanced computed tomography performed immediately after TACE. Therapeutic responses of HCCs were evaluated by CEUS 1 to 2 days after TACE and by contrast-enhanced computed tomography (CECT) approximately 4 weeks after TACE. We investigated the noninferiority of CEUS 1 to 2 days after TACE to CECT approximately 4 weeks after TACE in terms of the diagnostic accuracy of the therapeutic response to TACE on HCC.

RESULTS

Eighty-nine HCCs were enrolled in this study between April 2014 and June 2016. A complete response was observed in 57 of 89 nodules (64.0%), and an incomplete response was observed in the remaining 32 nodules (36.0%). The accuracy rates for CEUS 1 to 2 days after TACE and CECT approximately 4 weeks after TACE in the therapeutic effect of TACE on HCCs were 83.1% (95% confidence interval, 73.7%-90.2%) and 83.1% (95% confidence interval, 73.7%-90.2%), respectively. The difference in diagnostic accuracy between methods was 0%, which was below the predetermined noninferiority limit of 15%, and CEUS 1 to 2 days after TACE was noninferior to CECT approximately 4 weeks after TACE.

CONCLUSIONS

Our results suggest that CEUS is a useful modality for early therapeutic evaluation of TACE for HCC, and we can thus plan the next treatment strategies for HCC within a few days after TACE.

Usefulness of fusion images of unenhanced and contrast-enhanced arterial phase cone-beam CT in the detection of viable hepatocellular carcinoma during transarterial chemoembolization

PURPOSE

We aimed to evaluate the diagnostic efficacy of fusion imaging of unenhanced and arterial phase contrast-enhanced cone-beam computed tomography (CBCT) by comparing with multidetector computed tomography (MDCT) in detection of viable hepatocellular carcinoma (HCC) in patients who have been previously treated with transarterial chemoembolization (TACE).

METHODS

In this retrospective study, a total of 173 tumors in 33 known HCC patients (21 men, 12 women; mean age, 64±7.6 years; mean tumor size, 2.15±1.70 cm) who had been previously treated with TACE and underwent additional session of TACE were included. The sensitivity and positive predictive values of preprocedural MDCT and fusion CBCT for detection of viable tumor were analyzed with follow-up MDCT images performed 3-4 weeks after TACE, as reference standard.

RESULTS

A total of 141 remote and 32 marginal viable tumors were included. The sensitivities for detection of remote, marginal, and total viable tumors were 80.9%, 68.8%, and 78.6% for MDCT and 96.5%, 96.9%, and 96.5% for fusion CBCT, respectively. The positive predictive values for detection of remote, marginal, and total viable tumors were 95.0%, 78.6%, and 95.8% for MDCT, and 97.1%, 88.6%, and 97.7% for fusion CBCT, respectively. Fusion CBCT showed statistically higher sensitivity and positive predictive value for detection of viable tumors (P < 0.001).

CONCLUSION

The diagnostic performance of fusion imaging of unenhanced and contrast-enhanced arterial phase CBCT was superior to MDCT for detection of viable HCCs.

Contrast-Enhanced Ultrasonography Versus Contrast-Enhanced Computed Tomography for Assessment of Residual Tumor From Hepatocellular Carcinoma Treated With Transarterial Chemoembolization: A Meta-analysis

OBJECTIVES

This study reviewed the literature to directly evaluate the diagnostic performance of contrast-enhanced ultrasonography (CEUS) versus contrast-enhanced computed tomography (CECT) for assessing residual tumors of hepatocellular carcinoma treated with transarterial chemoembolization.

METHODS

PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure were searched through April 30, 2017. The pooled sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic curve were calculated and compared to examine the diagnostic performance of CEUS versus CECT.

RESULTS

A total of 11 studies, including 421 patients and 491 nodules were analyzed. The pooled diagnostic performances of CEUS versus CECT were as follows: (1) sensitivity (95% confidence interval), 0.97 (0.95-0.99) versus 0.72 (0.67-0.76); (2) specificity, 0.86 (0.74-0.94) versus 0.99 (0.95-1.00); (3) positive predictive value, 0.97 (0.95-0.99) versus 1.00 (0.98-1.00); (4) negative predictive value, 0.90 (0.83-0.95) versus 0.51 (0.44-0.58); (5) positive likelihood ratio, 7.79 (4.73-12.82) versus 12.50 (5.74-27.20); (6) negative likelihood ratio, 0.05 (0.03-0.09) versus 0.35 (0.26-0.48); (7) diagnostic odds ratio, 150.56 (57.03-397.49) versus 35.54 (14.89-84.83); and (8) area under the summary receiver operating characteristic curve, 0.9875 versus 0.9239. The sensitivity and negative predictive value of CEUS were significantly higher than those of CECT (both P < .001). The specificity and positive predictive value of CECT were significantly higher than those of CEUS (both P < .05).

CONCLUSIONS

Contrast-enhanced US, with better sensitivity and negative predictive value versus CECT, was an effective method for exclusion of residual tumors after transarterial chemoembolization. Contrast-enhanced CT, with higher specificity than CEUS, is a valid approach for identifying residual tumors.

Acetylated Polyethylenimine-Entrapped Gold Nanoparticles Enable Negative Computed Tomography Imaging of Orthotopic Hepatic Carcinoma

Developing an effective computed tomography (CT) contrast agent is still a challenging task for precise diagnosis of hepatic carcinoma (HCC). Here, we present the use of acetylated polyethylenimine (PEI)-entrapped gold nanoparticles (Ac-PE-AuNPs) without antifouling modification for negative CT imaging of HCC. PEI was first linked to fluorescein isothiocyanate (FI) and then utilized as a vehicle for the entrapment of AuNPs. The particles were then acetylated to reduce its positive surface potential. The designed Ac-PE-AuNPs were characterized by various techniques. We find that the Ac-PE-AuNPs with a uniform size distribution (mean diameter = 2.3 nm) are colloidally stable and possess low toxicity in the studied range of concentration. Owing to the fact that the particles without additional antifouling modification were mainly gathered in liver, the Ac-PE-AuNPs could greatly improve the CT contrast enhancement of normal liver, whereas poor CT contrast enhancement appeared in liver necrosis region caused by HCC. As a result, HCC could be easily and precisely diagnosed. The designed Ac-PE-AuNPs were demonstrated to have biocompatibility through in vivo biodistribution and histological studies, hence holding an enormous potential to be adopted as an effective negative CT contrast agent for diagnosis of hepatoma carcinoma.

Bench-to-clinic development of imageable drug-eluting embolization beads: finding the balance

This review describes the historical development of an imageable spherical embolic agent and focuses on work performed in collaboration between Biocompatibles UK Ltd (a BTG International group company) and the NIH to demonstrate radiopaque bead utility and bring a commercial offering to market that meets a clinical need. Various chemistries have been investigated and multiple prototypes evaluated in search of an optimized product with the right balance of handling and imaging properties. Herein, we describe the steps taken in the development of DC Bead LUMI™, the first commercially available radiopaque drug-eluting bead, ultimately leading to the first human experience of this novel embolic agent in the treatment of liver tumors.

Evaluation of Hepatocellular Carcinoma Transarterial Chemoembolization using Quantitative Analysis of 2D and 3D Real-time Contrast Enhanced Ultrasound

Quantitative 2D and 3D contrast-enhanced ultrasound (CEUS) was assessed to evaluate early transarterial chemoembolization (TACE) treatment response. Seventeen patients scheduled for TACE for the treatment of hepatocellular carcinoma participated in the study. 2D and 3D CEUS were performed for each patient at three time points: prior to TACE, 1-2 weeks post TACE, and 1 month post TACE. Peak-intensities of the tumor and surrounding liver tissue were calculated from 2D and 3D data before and after TACE and used to evaluate tumor treatment response. Residual tumor percentages were calculated from 2D and 3D CEUS acquired 1-2 weeks and 1 month post TACE and compared with results from MRI 1 month post TACE. Nine subjects had complete response while 8 had incomplete response. Peak-intensities of the tumor from 3D CEUS prior to TACE were similar between the complete and incomplete treatment groups (p=0.70), while 1-2 weeks (p<0.01) and 1 month post treatment (p<0.01) were significantly lower in the complete treatment group than in the incomplete treatment group. For 2D CEUS, only the peak-intensity values of the tumor from1 month post TACE were significantly different (p<0.01). The correlation coefficients between 2D and 3D residual tumor estimates 1-2 weeks post TACE and the estimates from MRI were 0.73 and 0.94, respectively, while those from 2D and 3D CEUS 1 month post TACE were 0.66 and 0.91, respectively. Quantitative analysis on 2D and 3D CEUS shows potential to differentiate patients with complete vs. incomplete response to TACE as early as 1-2 weeks post treatment.

Hepatic imaging following intra-arterial embolotherapy

PURPOSE

To discuss guidelines and salient imaging findings of solid tumors treated with common intra-arterial procedures used in interventional oncology.

METHODS

A meticulous literature search of PubMed-indexed articles was conducted. Key words included "imaging + embolization," "imaging + TACE," "imaging + radioembolization," "imaging + Y90," "mRECIST," and "EASL." Representative post-treatment cross-sectional images were obtained from past cases in this institution.

RESULTS

Intra-arterial therapy (IAT) in interventional oncology includes bland embolization, chemoembolization, and radioembolization. Solid tumors of the liver are the primary focus of these procedures. Cross-sectional CT and/or MR are the main modalities used to image tumors after treatment. Traditional size-based response criteria (WHO and RECIST) alone are of limited utility in determining response to IAT; tumoral necrosis and enhancement must be considered. Specifically for HCC, the EASL and mRECIST guidelines are becoming widely adopted response criteria to assess these factors. DWI, FDG-PET, and CEUS are modalities that play an adjunctive but controversial role.

CONCLUSIONS

Radiologists must be aware that the different forms of intra-arterial therapy yield characteristic findings on cross-sectional imaging. Knowledge of these findings is integral to accurate assessment of tumor response and progression.