Lipiodol retention pattern assessed by cone beam computed tomography during conventional transarterial chemoembolization of hepatocellular carcinoma: accuracy and correlation with response

Adjusted Tumor Enhancement on Dual-Phase Cone-Beam CT: Predictor of Response and Overall Survival in Patients with Liver Malignancies Treated with Hepatic Artery Embolization

The aim of this study was to examine the value of tumor enhancement parameters on dual-phase cone-beam CT (CBCT) in predicting initial response, local progression-free survival (L-PFS) and overall survival (OS) following hepatic artery embolization (HAE). Between Feb 2016 and Feb 2023, 13 patients with 29 hepatic tumors treated with HAE were analyzed. Pre- and post-embolization, subtracted CBCTs were performed, and tumor enhancement parameters were measured, resulting in three parameters: pre-embolization Adjusted Tumor Enhancement (pre-ATE), post-embolization ATE and the difference between pre- and post-ATE (∆ATE). Treatment response was evaluated using the mRECIST criteria at 1 month. Tumors were grouped into complete response (CR) and non-complete response (non-CR) groups. To account for the effect of multiple lesions per patient, a cluster data analytic method was employed. The Kaplan-Meier method was utilized for survival analysis using the lesion with the lowest ∆ATE value in each patient. Seventeen (59%) tumors showed CR and twelve (41%) showed non-CR. Pre-ATE was 38.5 ± 10.6% in the CR group and 30.4 ± 11.0% in the non-CR group (p = 0.023). ∆ATE in the CR group was 39 ± 12 percentage points following embolization, compared with 29 ± 11 in the non-CR group (p = 0.009). Patients with ∆ATE > 33 had a median L-PFS of 13.1 months compared to 5.7 in patients with ∆ATE ≤ 33 (95% CI = 0.038-0.21) (HR, 95% CI = 0.45, 0.20-0.9, p = 0.04). Patients with ∆ATE ≤ 33 had a median OS of 19.7 months (95% CI = 3.77-19.8), while in the ∆ATE > 33 group, median OS was not reached (95% CI = 20.3-NA) (HR, 95% CI = 0.15, 0.018-1.38, p = 0.04). CBCT-derived ATE parameters can predict treatment response, L-PFS and OS following HAE.

Response assessment methods for patients with hepatic metastasis from rare tumor primaries undergoing transarterial chemoembolization

PURPOSE

This study assessed the response to conventional transarterial chemoembolization (cTACE) in patients with liver metastases from rare tumor primaries using one-dimensional (1D) and three-dimensional (3D) quantitative response assessment methods, and investigate the relationship of lipiodol deposition in predicting response.

MATERIALS AND METHODS

This retrospective bicentric study included 16 patients with hepatic metastases from rare tumors treated with cTACE between 2002 and 2017. Multi-phasic MR imaging obtained before and after cTACE was used for assessment of response. Response evaluation criteria in solid tumors (RECIST) and modified-RECIST (mRECIST) were utilized for 1D response assessment, and volumetric RECIST (vRECIST) and enhancement-based quantitative European Association for Study of the Liver EASL (qEASL) were used for 3D response assessment. The same day post-cTACE CT scan was analyzed to quantify intratumoral lipiodol deposition (%).

RESULTS

The mean and standard deviation (SD) of diameter of treated lesions per targeted area was 7.5 ± 5.4 cm, and the mean and SD of number of metastases in each targeted area was 4.2 ± 4.6. cTACE was technically successful in all patients, without major complications. While RECIST and vRECIST methods did not allocate patients with partial response, mRECIST and qEASL identified patients with partial response. Intratumoral lipiodol deposition significantly predicted treatment response according qEASL (R² = 0.470, p < 0.01), while no association was shown between lipiodol deposition within treated tumor area and RECIST or mRECIST (p > 0.212).

CONCLUSION

3D quantitative volumetric response analysis can be used for stratification of response to cTACE in patients with hepatic metastases originating from rare primary tumors. Lipiodol deposition could potentially be used as an early surrogate to predict response to cTACE.

Value of Latest-generation Cone-beam Computed Tomography for Post Lipiodol-embolization Imaging in Hepatic Transarterial Chemoembolization in Comparison with Multi-detector Computed Tomography

RATIONALE AND OBJECTIVES

To evaluate image quality, radiation dose (phantom study) and tumor volumetry of intraprocedural cone-beam computed tomography (CBCT) compared to postprocedural multidetector computed tomography (MDCT) in patients undergoing hepatic conventional transarterial chemoembolization (cTACE).

MATERIALS AND METHODS

One hundred fourteen patients (64/50 female/male; mean age, 57 ± 14 years) who had undergone cTACE including intraprocedural-CBCT and postprocedural-MDCT were retrospectively enrolled. Subjective image quality (IQ) and suitability for assessing Lipiodol distribution were compared using 4-point Likert scales; additionally, lesion to liver contrast (LLC) and contrast-to-noise-ratio (CNR) were compared. Tumor volumes were measured semi-automatically and compared to magnetic resonance imaging (MRI). Effective doses were measured using an anthropomorphic phantom.

RESULTS

The suitability of CBCT for assessing Lipiodol distribution during cTACE was comparable to MDCT (mean score, 3.2 ± 0.6) and CBCT (3.4 ± 1.0, p = 0.29). Subjective overall IQ was rated with a mean score of 3.2 ± 0.7 (κ = 0.66) in CBCT and 3.1 ± 0.4 (κ = 0.57, p = 0.15) in MDCT. Evaluation of LLC showed significant differences between CBCT and MDCT (mean scores 3.6 ± 1.2 and 2.6 ± 1.5, respectively). CNR analysis demonstrated comparable mean values for CBCT and MDCT (3.5 ± 1.3 vs. 3.4 ± 1.8, p = 0.31). No significant differences were found regarding tumor volumetry (mean volumes: CBCT, 27.0 ± 17.4 mm3; MDCT: 26.8 ± 16.0 mm3; p = 0.66) in comparison to T2-weighted MRI (25.9 ± 17.6 mm3). Effective doses were 3.2 ± 0.6 mSv (CBCT) and 2.5 ± 0.3 mSv (MDCT) (p < 0.001). No cTACE-related complications (bleeding, non-target embolization) were missed on intraprocedural CBCT in comparison to postprocedural MDCT.

CONCLUSION

Latest-generation intraprocedural CBCT provides suitable assessment of Lipiodol distribution and similar image quality compared to MDCT while allowing for robust volumetric tumor measurements and immediate complication control by visualizing non-target embolization and hematoma. Therefore, it may improve patient safety and outcome as well as clinical workflow compared to postprocedural MDCT in hepatic cTACE in certain cases.

Quantitative Automated Segmentation of Lipiodol Deposits on Cone Beam CT Imaging acquired during Transarterial Chemoembolization for Liver Tumors: A Deep Learning Approach

PURPOSE

The purpose of this study was to show that a deep learning-based, automated model for Lipiodol segmentation on CBCT after cTACE performs closer to the "ground truth segmentation" than a conventional thresholding-based model.

MATERIALS & METHODS

This post-hoc analysis included 36 patients with a diagnosis of HCC or other solid liver tumor who underwent cTACE with an intra-procedural CBCT. Semi-automatic segmentation of Lipiodol were obtained. Then, a convolutional U-net model was used to output a binary mask that predicts Lipiodol deposition. A threshold value of signal intensity on CBCT was used to obtain a Lipiodol mask for comparison. Dice similarity coefficient (DSC), Mean-squared error (MSE), and Center of Mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist segmented Lipiodol deposits) to obtain accuracy metrics for the two masks. These results were used to compare the model vs. the threshold technique.

RESULTS

For all metrics, the U-net outperformed the threshold technique: DSC (0.65±0.17 vs. 0.45±0.22,p<0.001) and MSE (125.53±107.36 vs. 185.98±93.82,p=0.005). Difference between the CM predicted, and the actual CM was (15.31±14.63mm vs. 31.34±30.24mm,p<0.001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22±0.84vs.2.58±3.52,p=0.048 for our model's prediction and threshold technique, respectively.

CONCLUSION

This study showed that a deep learning framework could detect Lipiodol in CBCT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intra-procedurally.

Lipiodol Deposition and Washout in Primary and Metastatic Liver Tumors After Chemoembolization

BACKGROUND/AIM

Lipiodol is the key component of conventional trans-arterial chemoembolization. Our aim was to evaluate lipiodol deposition and washout rate after conventional trans-arterial chemoembolization in intrahepatic cholangiocarcinoma and hepatic metastases originating from neuroendocrine tumors and colorectal carcinoma.

PATIENTS AND METHODS

This was a retrospective analysis of 44 patients with intrahepatic cholangiocarcinoma and liver metastasis from neuroendocrine tumors or colorectal carcinoma who underwent conventional trans-arterial chemoembolization. Lipiodol volume (cm³) was analyzed on non-contrast computed tomography imaging obtained within 24 h post conventional trans-arterial chemoembolization, and 40-220 days after conventional trans-arterial chemoembolization using volumetric image analysis software. Tumor response was assessed on contrast-enhanced magnetic resonance imaging 1 month after conventional trans-arterial chemoembolization.

RESULTS

The washout rate was longer for neuroendocrine tumors compared to colorectal carcinoma, with half-lives of 54.61 days (p<0.00001) and 19.39 days (p<0.001), respectively, with no exponential washout among intrahepatic cholangiocarcinomas (p=0.83). The half-life for lipiodol washout was longer in tumors larger than 300 cm³ compared to smaller tumors (25.43 vs. 22.71 days). Lipiodol wash out half-life was 54.76 days (p<0.01) and 29.45 days (p<0.00001) for tumors with a contrast enhancement burden of 60% or more and less than 60%, respectively. A negative exponential relationship for lipiodol washout was observed in non-responders (p<0.00001).

CONCLUSION

Lipiodol washout is a time-dependent process, and occurs faster in colorectal carcinoma tumors, tumors smaller than 300 cm³, tumors with baseline contrast enhancement burden of less than 60%, and non-responding target lesions.

Lipiodol as an intra-procedural imaging biomarker for liver tumor response to transarterial chemoembolization: Post-hoc analysis of a prospective clinical trial

BACKGROUND

The use of the ethiodized oil- Lipiodol in conventional trans-arterial chemoembolization (cTACE) ensures radiopacity to visualize drug delivery in the process of providing selective drug targeting to hepatic cancers and arterial embolization. Lipiodol functions as a carrier of chemo drugs for targeted therapy, as an embolic agent, augmenting the drug effect by efflux into the portal veins as well as a predictor for the tumor response and survival.

PURPOSE

To prospectively evaluate the role of 3D quantitative assessment of intra-procedural Lipiodol deposition in liver tumors on CBCT immediately after cTACE as a predictive biomarker for the outcome of cTACE.

MATERIALS & METHODS

This was a post-hoc analysis of data from an IRB-approved prospective clinical trial. Thirty-two patients with hepatocellular carcinoma or liver metastases underwent contrast enhanced CBCT obtained immediately after cTACE, unenhanced MDCT at 24 h after cTACE, and follow-up imaging 30-, 90- and 180-days post-procedure. Lipiodol deposition was quantified on CBCT after cTACE and was characterized by 4 ordinal levels: ≤25%, >25-50%, >50-75%, >75%. Tumor response was assessed on follow-up MRI. Lipiodol deposition on imaging, correlation between Lipiodol deposition and tumor response criteria, and correlation between Lipiodol coverage and median overall survival (MOS) were evaluated.

RESULTS

Image analysis demonstrated a high degree of agreement between the Lipiodol deposition on CBCT and the 24 h post-TACE CT, with a Bland-Altman plot of Lipiodol deposition on imaging demonstrated a bias of 2.75, with 95%-limits-of-agreement: -16.6 to 22.1%. An inverse relationship between Lipiodol deposition in responders versus non-responders for two-dimensional EASL reached statistical significance at 30 days (p = 0.02) and 90 days (p = 0.05). Comparing the Lipiodol deposition in Modified Response Evaluation Criteria in Solid Tumors (mRECIST) responders versus non-responders showed a statistically significant higher volumetric deposition in responders for European Association for the Study of the Liver (EASL)-30d, EASL-90d, and quantitative EASL-180d. The correlation between the relative Lipiodol deposition and the change in enhancing tumor volume showed a negative association post-cTACE (30-day: p < 0.001; rho = -0.63). A Kaplan-Meier analysis for patients with high vs. low Lipiodol deposition showed a MOS of 46 vs. 33 months (p = 0.05).

CONCLUSION

3D quantification of Lipiodol deposition on intra-procedural CBCT is a predictive biomarker of outcome in patients with primary or metastatic liver cancer undergoing cTACE. There are spatial and volumetric agreements between 3D quantification of Lipiodol deposition on intra-procedural CBCT and 24 h post-cTACE MDCT. The spatial and volumetric agreement between Lipiodol deposition on intra-procedural CBCT and 24 h post-cTACE MDCT could suggest that acquiring MDCT 24 h after cTACE is redundant. Importantly, the demonstrated relationship between levels of tumor coverage with Lipiodol and degree and timeline of tumor response after cTACE underline the role of Lipiodol as an intra-procedural surrogate for tumor response, with potential implications for the prediction of survival.

Early prediction of 1-year tumor response of hepatocellular carcinoma with lipiodol deposition pattern through post-embolization cone-beam computed tomography during conventional transarterial chemoembolization

OBJECTIVE

To evaluate whether parenchyma-to-lipiodol ratio (PLR) and lesion-to-lipiodol ratio (LLR) on C-arm cone-beam computed tomography (CBCT) can predict 1-year tumor response in patients with hepatocellular carcinoma (HCC) treated with conventional transcatheter arterial chemoembolization (cTACE).

METHODS

This retrospective analysis included 221 HCC target lesions within up-to-seven criteria in 80 patients who underwent cTACE with arterial-phase CBCT and unenhanced CBCT after cTACE from 2015 to 2018. PLR and LLR of every tumor slice were obtained through mean density division of liver parenchyma and tumor enhancement with intratumoral lipiodol deposition. The cutoff values (COVs) of maximal PLR and LLR of every tumor were analyzed using Youden's index. The reliability of COV, correlations between the related parameters, and 1-year progression were assessed through interobserver agreement and multivariate analysis. COV validity was verified using the chi-square test and Cramer's V coefficient (V) in the validation cohort.

RESULTS

Standard COVs of PLR and LLR were 0.149 and 1.4872, respectively. Interobserver agreement of COV for PLR and LLR was near perfect (kappa > 0.9). Multivariate analysis suggested that COV of PLR is an independent predictor (odds ratio = 1.23532×10¹⁴, p = 4.37×10^-7). COV of PLR showed strong consistency, correlation with 1-year progression in prediction model (V = 0.829-0.776; p < 0.0001), and presented as an effective predictor in the validation cohort (V = 0.766; p < 0.0001).

CONCLUSION

The COV of PLR (0.149) assessed through immediate post-embolization CBCT is an objective, effective, and approachable predictor of 1-year HCC progression after cTACE.

KEY POINTS

• The maximal PLR value indicates the least lipiodol-distributed region in an HCC tumor. The maximal LLR value indicates the least lipiodol-deposited region in the tumor due to incomplete lipiodol delivery. PLR and LLR are concepts like signal-to-noise ratio to characterize the lipiodol retention pattern objectively to predict 1-year tumor progression immediately without any quantification software for 3D image analysis immediately after cTACE treatment. • COV of PLR can facilitate the early prediction of tumor progression/recurrence and indicate the section of embolized HCC, providing the operator's good targets for sequential cTACE or combined ablation. • The validation cohort in our study verified standard COVs of PLR and LLR. The validation process was more convincing and delicate than that of previous retrospective studies.

Findings on intraprocedural non-contrast computed tomographic imaging following hepatic artery embolization are associated with development of contrast-induced nephropathy

BACKGROUND

Contrast-induced nephropathy (CIN) is a reversible form of acute kidney injury that occurs within 48-72 h of exposure to intravascular contrast material. CIN is the third leading cause of hospital-acquired acute kidney injury and accounts for 12% of such cases. Risk factors for CIN development can be divided into patient- and procedure-related. The former includes pre-existing chronic renal insufficiency and diabetes mellitus. The latter includes high contrast volume and repeated exposure over 72 h. The incidence of CIN is relatively low (up to 5%) in patients with intact renal function. However, in patients with known chronic renal insufficiency, the incidence can reach up to 27%.

AIM

To examine the association between renal enhancement pattern on non-contrast enhanced computed tomographic (CT) images obtained immediately following hepatic artery embolization with development of CIN.

METHODS

Retrospective review of all patients who underwent hepatic artery embolization between 01/2010 and 01/2011 (n = 162) was performed. Patients without intraprocedural CT imaging (n = 51), combined embolization/ablation (n = 6) and those with chronic kidney disease (n = 21) were excluded. The study group comprised of 84 patients with 106 procedures. CIN was defined as 25% increase above baseline serum creatinine or absolute increase ≥ 0.5 mg/dL within 72 h post-embolization. Post-embolization CT was reviewed for renal enhancement patterns and presence of renal artery calcifications. The association between non-contrast CT findings and CIN development was examined by Fisher’s Exact Test.

RESULTS

CIN occurred in 11/106 (10.3%) procedures (Group A, n = 10). The renal enhancement pattern in patients who did not experience CIN (Group B, n = 74 with 95/106 procedures) was late excretory in 93/95 (98%) and early excretory (EE) in 2/95 (2%). However, in Group A, there was a significantly higher rate of EE pattern (6/11, 55%) compared to late excretory pattern (5/11) (P < 0.001). A significantly higher percentage of patients that developed CIN had renal artery calcifications (6/11 vs 20/95, 55% vs 21%, P = 0.02).

CONCLUSION

A hyperdense renal parenchyma relative to surrounding skeletal muscle (EE pattern) and presence of renal artery calcifications on immediate post-HAE non-contrast CT images in patients with low risk for CIN are independently associated with CIN development.

Prospective study of Lipiodol distribution as an imaging marker for doxorubicin pharmacokinetics during conventional transarterial chemoembolization of liver malignancies

OBJECTIVES

To evaluate the prognostic potential of Lipiodol distribution for the pharmacokinetic (PK) profiles of doxorubicin (DOX) and doxorubicinol (DOXOL) after conventional transarterial chemoembolization (cTACE).

METHODS

This prospective clinical trial ( ClinicalTrials.gov : NCT02753881) included 30 consecutive participants with liver malignancies treated with cTACE (5/2016-10/2018) using 50 mg DOX/10 mg mitomycin C emulsified 1:2 with ethiodized oil (Lipiodol). Peripheral blood was sampled at 10 timepoints for standard non-compartmental analysis of peak concentrations (C_max) and area under the curve (AUC) with dose normalization (DN). Imaging markers included Lipiodol distribution on post-cTACE CT for patient stratification into 1 segment (n = 10), ≥ 2 segments (n = 10), and lobar cTACE (n = 10), and baseline enhancing tumor volume (ETV). Adverse events (AEs) and tumor response on MRI were recorded 3-4 weeks post-cTACE. Statistics included repeated measurement ANOVA (RM-ANOVA), Mann-Whitney, Kruskal-Wallis, Fisher's exact test, and Pearson correlation.

RESULTS

Hepatocellular (n = 26), cholangiocarcinoma (n = 1), and neuroendocrine metastases (n = 3) were included. Stratified according to Lipiodol distribution, DOX-C_max increased from 1 segment (DOX-C_max, 83.94 ± 75.09 ng/mL; DN-DOX-C_max, 2.67 ± 2.02 ng/mL/mg) to ≥ 2 segments (DOX-C_max, 139.66 ± 117.73 ng/mL; DN-DOX-C_max, 3.68 ± 4.20 ng/mL/mg) to lobar distribution (DOX-C_max, 334.35 ± 215.18 ng/mL; DN-DOX-C_max, 7.11 ± 4.24 ng/mL/mg; p = 0.036). While differences in DN-DOX-AUC remained insignificant, RM-ANOVA revealed significant separation of time concentration curves for DOX (p = 0.023) and DOXOL (p = 0.041) comparing 1, ≥ 2 segments, and lobar cTACE. Additional indicators of higher DN-DOX-C_max were high ETV (p = 0.047) and Child-Pugh B (p = 0.009). High ETV and tumoral Lipiodol coverage also correlated with tumor response. AE occurred less frequently after segmental cTACE.

CONCLUSIONS

This prospective clinical trial provides updated PK data revealing Lipiodol distribution as an imaging marker predictive of DOX-C_max and tumor response after cTACE in liver cancer.

KEY POINTS

• Prospective pharmacokinetic analysis after conventional TACE revealed Lipiodol distribution (1 vs. ≥ 2 segments vs. lobar) as an imaging marker predictive of doxorubicin peak concentrations (C_max). • Child-Pugh B class and tumor hypervascularization, measurable as enhancing tumor volume (ETV) at baseline, were identified as additional predictors for higher dose-normalized doxorubicin C_max after conventional TACE. • ETV at baseline and tumoral Lipiodol coverage can serve as predictors of volumetric tumor response after conventional TACE according to quantitative European Association for the Study of the Liver (qEASL) criteria.

Embolotherapy for Hepatic Oncology: Current Perspectives and Future Directions

Primary and secondary liver cancers are a major cause of mortality worldwide. Transarterial liver-directed therapy, or embolotherapy, represents an important locoregional treatment strategy for primary and secondary liver tumors. Embolotherapeutic modalities include bland embolization (transarterial embolization), chemoembolization (transarterial chemoembolization), and radioembolization or selective internal radiotherapy. A brief technical overview of embolotherapeutic modalities as well as supportive evidence for the treatment of most common primary and secondary liver tumors will be discussed in this review. Several potential future applications, including synergy with systemic therapy, interventional theranostics, and artificial intelligence will also be reviewed briefly.

Theranostic application of lipiodol for transarterial chemoembolization in a VX2 rabbit liver tumor model

The goal of this study was to investigate the role of Lipiodol as a tumor-specific imaging biomarker to determine therapeutic efficacy of cTACE and investigate its inter-dependency with tumor perfusion using radiological-pathological correlation in an animal model of liver cancer.

METHODS

A total of N=36 rabbits were implanted in the left lobe of the liver with VX2 tumors, treated with cTACE using doxorubicin suspended in Lipiodol, and randomly sacrificed at 24 h, 7 days, or 20 days post-TACE. Unenhanced and contrast-enhanced CT scans including a perfusion protocol were obtained before cTACE and immediately before sacrifice. Tumor vascularity and Lipiodol deposition within tumors and hepatic tissue (non-target deposits) were quantified using 3D quantitative assessment tools and measurements of arterial flow, portal flow, and perfusion index (PI). After sacrifice histologic staining, including hematoxylin and eosin (H&E), CD31, and Oil Red O (ORO) were performed on tumor and liver samples to evaluate necrosis, microvascular density (MVD), and Lipiodol retention over time. Transmission electron microscopy (TEM) was performed to assess Lipiodol deposition and clearance over time.

RESULTS

All cTACE procedures were carried out successfully except for one, which was excluded from further analysis. Twenty-four hours post-TACE, tumor PI (p=0.04) was significantly decreased, which was maintained at 7 days (p=0.003), but not at 20 days (p=0.4). A strong correlation (R2 = 0.894) was found between the volume of enhancing tumor tissue at baseline and Lipiodol-positive tumor volume post-TACE. Both ORO and TEM showed deposition of Lipiodol across all imaging time points within the VX2 tumors. However, gradual and ultimately near-complete Lipiodol washout was observed over time in the non-tumoral liver. MVD decreased between 24 h and 7 days post-TACE, and then increased 20 days post-TACE (both p<0.01).

CONCLUSIONS

Our data provide radiology-pathology evidence for the function of Lipiodol as a theranostic, tumor-specific drug delivery agent because it is both imageable and tumor-seeking, whereby it is preferentially taken up and retained by tumor cells. Those tumor-specific functions also enable Lipiodol to act as an imaging biomarker for the therapeutic efficacy of cTACE. Together with volumetric quantification of tumor vascularization on CT, Lipiodol could be used as a predictor of a patient's response to cTACE and contribute to the therapeutic management of patients with liver cancer.

Angio-Computed Tomograph-Guided Immediate Lipiodol Computed Tomograph for Diagnosis of Small Hepatocellular Carcinoma Lesions during Transarterial Chemoembolization

BACKGROUND

The diagnosis and treatment of small hepatocellular carcinoma (HCC) play a vital role in the prognosis of patients with HCC. The purpose of our study was to evaluate angio-computed tomography (angio-CT)-guided immediate lipiodol CT (a CT scan performed immediately after transarterial chemoembolization [TACE]) in the diagnosis of potential HCCs ≤1 cm in diameter.

METHODS

This study retrospectively analyzed 31 patients diagnosed with HCCs after routine imaging (contrast-enhanced CT or magnetic resonance imaging) or pathologic examinations with undefined or undetermined tumor lesions (diameter ≤1 cm) from February 2016 to September 2016. After TACE guided by digital subtraction angiography of the angio-CT system, potential HCC lesions with a diameter ≤1 cm were diagnosed by immediate lipiodol CT. The number of well-demarcated lesions was recorded to calculate the true positive rate. The correlation between the number of small HCCs detected by immediate lipiodol CT and the size of HCC lesions (diameter >1 cm) diagnosed preoperatively was analyzed 1 month after TACE. A paired t-test was used to analyze differences in liver function. Pearson analysis was used to analyze correlation. Chi-square test was used to compare the rates.

RESULTS

Fifty-eight lesions were detected on preoperative routine imaging examinations in 31 patients including 15 lesions with a diameter ≤1 cm. Ninety-one lesions were detected on immediate lipiodol CT, of which 48 had a diameter ≤1 cm. After 1 month, CT showed that 45 lesions had lipiodol deposition and three lesions had lipiodol clearance. Correlation analysis showed that the number of small HCCs detected by lipiodol CT was positively correlated with the size of HCC lesions diagnosed by conventional imaging examination (R2 = 0.54, P < 0.05).

CONCLUSION

Immediate lipiodol CT may be a useful tool in the diagnosis of potential HCC lesions with a diameter of ≤1 cm.

Hepatocellular Carcinoma: Diagnosis, Treatment Algorithms, and Imaging Appearance after Transarterial Chemoembolization

Hepatocellular carcinoma (HCC) is a common cause of cancer-related death, with incidence increasing worldwide. Unfortunately, the overall prognosis for patients with HCC is poor and many patients present with advanced stages of disease that preclude curative therapies. Diagnostic and interventional radiologists play a key role in the management of patients with HCC. Diagnostic radiologists can use contrast-enhanced computed tomography (CT), magnetic resonance imaging, and ultrasound to diagnose and stage HCC, without the need for pathologic confirmation, by following established criteria. Once staged, the interventional radiologist can treat the appropriate patients with percutaneous ablation, transarterial chemoembolization, or radioembolization. Follow-up imaging after these liver-directed therapies for HCC can be characterized according to various radiologic response criteria; although, enhancement-based criteria, such as European Association for the Study of the Liver and modified Response Evaluation Criteria in Solid Tumors, are more reflective of treatment effect in HCC. Newer imaging technologies like volumetric analysis, dual-energy CT, cone beam CT and perfusion CT may provide additional benefits for patients with HCC.

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.