Optimal measurement modality and method for evaluation of responses to transarterial chemoembolization of hepatocellular carcinoma based on enhancement criteria

Inter-Reader Agreement in LR-TRA Application and NLR Association in HCC Patients Treated with Endovascular vs. Ablative Procedures

OBJECTIVES

This study aimed to assess the performance of the LI-RADS tumor response algorithm in analyzing inter-reader agreement in patients with hepatocellular carcinoma (HCC) treated with Microwave Ablation (MWA) and Transarterial Embolization (TAE) and the relationship between inter-reader agreement and Neutrophils to Lymphocytes ratio dynamic variations at different time points to explore how inflammation influences tumor response and its interpretation on imaging.

METHODS

A retrospective analysis was conducted on 78 HCC patients treated with MWA or TAE. Two independent radiologists evaluated pre- and post-treatment imaging and assigned categories according to the LR-TRA. Inter-reader agreement was assessed with a focus on subgroup analysis considering the different locoregional treatments. NLR values, measured at baseline (T0), 72 h (T1), and 30 days post-procedure (T2), were compared with patients with concordant and discordant LR-TRA assessments. This analysis aimed to identify any association between NLR dynamics and inter-reader agreement on treatment response.

RESULTS

The inter-reader agreement in the LR-TRA application was "substantial" in the cases of MWA treatment evaluation (κ = 0.65), and "moderate" in the cases of TAE treatment evaluation (κ = 0.51). The differences in inter-reader agreement were found to be expressions of different levels of NLR mean values in the different time frames evaluated. Three days after treatment, NLR increased significantly in TAE groups. At 30 days, NLR had returned close to baseline levels but with NLR persisting higher in the TAE group. There was a statistically significant difference in NLR between the "mismatch" group (those with discrepant LR-TRA readings) and the "match" group at 3 days (p = 0.004) and late evaluation (30+ days).

CONCLUSIONS

This study has shown that NLR levels can predict inter-reader discrepancies in LR-TRA assessment and may be translated into different levels of difficult imaging interpretation. Combining LR-TRA and NLR is promising for a more comprehensive assessment of tumor response and inflammatory dynamics.

Influence of the Radiological Response on Histological Necrosis and on the Survival of Patients Treated With Transarterial Chemoembolization for Hepatocellular Carcinoma Secondary to Cirrhosis on the Liver Transplantation Waiting List

BACKGROUND AND AIMS

Transarterial chemoembolization is the most common treatment used for HCC patients on liver transplant waiting list. The aims of this study are to evaluate the radio-histological correlation of the post-chemoembolization HCC response and its influence on overall survival (OS) and recurrence-free survival (RFS).

METHODS

Monocentric, retrospective study, including liver transplant patients with HCC who received chemoembolization from 2007 to 2018. The response of the hypervascular nodules was evaluated according to mRECIST, EASL.

RESULTS

A total of 70 patients with 122 hypervascular and 28 hypovascular HCCs were included. A complete radiological response concerned 34.3% patients. Concordance rates of hypervascular nodules (mRECIST, EASL and lipiodol uptake) with tumor necrosis ranged from 49% to 57%, with a specificity of 35% and a positive predictive value of 54%. Bilobar involvement was a predictive factor for incomplete radiological response. Major tumor necrosis was significantly correlated with the decrease in αFP level between the first CEL and liver transplantation. OS and RFS at 5 years were 64% and 60%, respectively, and 69% and 66% at complete radiological response.

CONCLUSION

Radiological response is significantly related to histological tumor necrosis, but with poor prediction. In case of complete radiological response, OS and RFS seem to be improved.

Appropriate use of morphological imaging for assessing treatment response and disease progression of neuroendocrine tumors

Neuroendocrine tumors (NETs) are relatively rare neoplasms displaying heterogeneous clinical behavior, ranging from indolent to aggressive forms. Patients diagnosed with NETs usually receive a varied array of treatments, including somatostatin analogs, locoregional treatments (ablation, intra-arterial therapy), cytotoxic chemotherapy, peptide receptor radionuclide therapy (PRRT), and targeted therapies. To maximize therapeutic efficacy while limiting toxicity (both physical and economic), there is a need for accurate and reliable tools to monitor disease evolution and progression and to assess the effectiveness of these treatments. Imaging morphological methods, primarily relying on computed tomography (CT) and magnetic resonance imaging (MRI), are indispensable modalities for the initial evaluation and continuous monitoring of patients with NETs, therefore playing a pivotal role in gauging the response to treatment. The primary goal of assessing tumor response is to anticipate and weigh the benefits of treatments, especially in terms of survival gain. The World Health Organization took the pioneering step of introducing assessment criteria based on cross-sectional imaging. This initial proposal standardized the measurement of lesion sizes, laying the groundwork for subsequent criteria. The Response Evaluation Criteria in Solid Tumors (RECIST) subsequently refined and enhanced these standards, swiftly gaining acceptance within the oncology community. New treatments were progressively introduced, targeting specific features of NETs (such as tumor vascularization or expression of specific receptors), and achieving significant qualitative changes within tumors, although associated with minimal or paradoxical effects on tumor size. Several alternative criteria, adapted from those used in other cancer types and focusing on tumor viability, the slow growth of NETs, or refining the existing size-based RECIST criteria, have been proposed in NETs. This review article aims to describe and discuss the optimal utilization of CT and MRI for assessing the response of NETs to treatment; it provides a comprehensive overview of established and emerging criteria for evaluating tumor response, along with comparative analyses. Molecular imaging will not be addressed here and is covered in a dedicated article within this special issue.

Optimal imaging criteria and modality to determine Milan criteria for the prediction of post-transplant HCC recurrence after locoregional treatment

OBJECTIVES

We aimed to investigate the optimal radiologic method to determine Milan criteria (MC) for the prediction of recurrence in patients who underwent locoregional treatment (LRT) for hepatocellular carcinoma (HCC) and subsequent liver transplantation (LT).

METHODS

This retrospective study included 121 HCC patients who underwent LRT and had both liver dynamic CT and MRI. They were classified with MC using four cross combinations of two imaging modalities (CT and MRI) and two diagnostic criteria (modified Response Evaluation Criteria in Solid Tumors [mRECIST] and Liver Imaging Reporting and Data System treatment response algorithm [LI-RADS TRA]). Competing risk regression was performed to analyze the time to recurrence after LT. The predictive abilities of the four methods for recurrence were evaluated using the time-dependent area under the curve (AUC).

RESULTS

Competing risk regression analyses found that beyond MC determined by MRI with mRECIST was independently associated with recurrence (hazard ratio, 6.926; p = 0.001). With mRECIST, MRI showed significantly higher AUCs than CT at 3 years and 5 years after LT (0.597 vs. 0.756, p = 0.012 at 3 years; and 0.588 vs. 0.733, p = 0.024 at 5 years). Using the pathologic reference standard, MRI with LI-RADS TRA showed higher sensitivity (61.5%) than CT with LI-RADS TRA (30.8%, p < 0.001) or MRI with mRECIST (38.5%, p < 0.001).

CONCLUSIONS

MRI with mRECIST was the optimal radiologic method to determine MC for the prediction of post-LT recurrence in HCC patients with prior LRT.

KEY POINTS

• MRI with modified RECIST (mRECIST) is the optimal preoperative method to determine Milan criteria for the prediction of post-transplant HCC recurrence in patients with prior locoregional treatment. • With mRECIST, MRI was better than CT for the prediction of post-transplant recurrence.

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.

Nomogram for predicting pathologic complete response after transarterial chemoembolization in patients with hepatocellular carcinoma

Background

The pathologic responses to transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC) are heterogeneous and result in disparate outcomes. The study aimed to establish and validate an effective nomogram for predicting pathologic complete response (PCR) after TACE.

Methods

We analyzed the clinicopathologic characteristics of HCC patients undergoing hepatectomy following TACE. Variables with statistical significance in a multivariate logistic regression analysis were incorporated in the nomogram.

Results

We detected PCR in 64 (50.4%) patients in the training cohort and 18 (37.5%) patients in the validation cohort. Univariable and multivariable logistic regression revealed that hepatitis B virus (HBV) DNA load (P=0.031), α-fetoprotein (AFP, P=0.040), maximum tumor diameter (P=0.003), preoperative TACE session (P=0.026), and modified Response Evaluation Criteria in Solid Tumors (mRECIST) complete response (P=0.030) were identified as significant predictors of PCR. Incorporating these 5 factors, a nomogram was developed which attained concordance indexes of 0.80 [95% confidence interval (CI): 0.72–0.87] and 0.82 (95% CI: 0.68–0.95) for predicting PCR in the training and validation cohorts, respectively.

Conclusions

The easy-to-use nomogram achieved a good post-TACE prediction of PCR in HCC patients. Using the model, patients who would benefit most from TACE could be identified, and the subsequent appropriate procedures could be guided accordingly.

Interreader Reliability of Liver Imaging Reporting and Data System Treatment Response: A Systematic Review and Meta-Analysis

BACKGROUND

For a proper management strategy in patients with locoregionally treated hepatocellular carcinoma (HCC), it is essential that the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (LR-TR) has high interreader reliability. We aimed to systematically evaluate the interreader reliability of LR-TR and sources of any study heterogeneity.

METHODS

Original studies reporting the interreader reliability of LR-TR were identified in MEDLINE and EMBASE up to 20 September 2020. The pooled kappa coefficient (κ) was calculated using the DerSimonian-Laird random effects model. Subgroup analyses were performed according to imaging modality (magnetic resonance imaging (MRI) or computed tomography (CT)). Meta-regression analyses were performed to explore study heterogeneity.

RESULTS

Eight studies with 851 HCCs were finally included. Pooled κ was 0.70 (95% CI, 0.58-0.82) for CT/MRI LR-TR, and those of MRI and CT were 0.71 (95% CI, 0.53-0.89) and 0.71 (95% CI, 0.65-0.78), respectively. Study design (p < 0.001) and type of treatment (p = 0.02) were significantly associated with substantial study heterogeneity.

CONCLUSION

LR-TR showed substantial interreader reliability regardless of the imaging modality. Because of substantial study heterogeneity, which was significantly associated with study design and type of treatment, published values for the interreader reliability of LR-TR should be interpreted with care.

Diagnostic performance of Liver Imaging Reporting and Data System treatment response algorithm: a systematic review and meta-analysis

OBJECTIVE

To systematically determine the accuracy of Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm for diagnosing the viability of hepatocellular carcinoma (HCC) treated with locoregional therapy (LRT).

METHODS

Original studies reporting the diagnostic accuracy of LR-TR algorithm on dynamic contrast-enhanced computed tomography or magnetic resonance imaging (MRI) were identified in MEDLINE and EMBASE up to June 1, 2020. The meta-analytic summary sensitivity and specificity of LR-TR algorithm were calculated using a bivariate random-effects model. Subgroup analyses and meta-regression analysis were performed to explore study heterogeneity.

RESULTS

We found six studies reporting the accuracy of LR-TR viable category (601 observations in 453 patients). The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% confidence interval [CI], 39-81%; I² = 88%) and 96% (95% CI, 91-99%; I² = 76%), respectively. The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55-84%; I² = 89%) and 87% (95% CI, 73-94% I² = 80%), respectively. Studies which used only MRI showed a trend towards higher sensitivity (71% [95% CI, 46-88%]) with a comparable specificity (95% [95% CI, 86-99%]) of LR-TR viable category compared to the whole group. The type of reference standard and study design were significantly associated with study heterogeneity (p ≤ 0.01).

CONCLUSIONS

The LR-TR viable category had high specificity but suboptimal sensitivity for diagnosing the viability of HCC after LRT. Substantial study heterogeneity was noted, and it was significantly associated with the type of reference standard and study design.

KEY POINTS

• The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% CI, 39-81%) and 96% (95% CI, 91-99%), respectively. • The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55-84%) and 87% (95% CI, 73-94%), respectively. • The type of reference standard and study design were the factors significantly influencing study heterogeneity (p ≤ 0.01).

Spectral CT-Based Iodized Oil Quantification to Predict Tumor Response Following Chemoembolization of Hepatocellular Carcinoma

PURPOSE

To quantify iodized oil retention in tumors after transarterial chemoembolization using spectral computed tomography (CT) imaging in patients with hepatocellular carcinoma (HCC) and evaluate its performance in predicting 12-month tumor responses.

MATERIALS AND METHODS

From September 2017 to December 2018, 111 patients with HCC underwent initial conventional transarterial chemoembolization. Immediately after the procedure, unenhanced CT was performed using a spectral CT scanner, and the iodized oil densities in index tumors were measured. In tumor-level analyses, a threshold level of iodized oil density in the tumors was calculated using clustered receiver operating characteristic curve analyses to predict the 12-month tumor responses. In patient-level analyses, significant factors associated with a 12-month complete response, including the presence of tumors below the threshold value (ie, suspected residual tumors), were evaluated by logistic regression.

RESULTS

Forty-eight HCCs in 39 patients were included in the analyses. The lower 10th percentile of the iodine density was identified as the threshold for determining the 12-month nonviable responses. The area under the curve of the iodine density measurements in predicting the 12-month nonviable responses was 0.893 (95% confidence interval, 0.797-0.989). The threshold value of the iodine density of 10.68 mg/mL yielded a sensitivity of 82.76% and specificity of 94.74% (P < .001). In the patient-level analysis, the 12-month complete response was significantly associated with the presence of a suspected residual tumor, with an odds ratio of 72.0 (95% confidence interval, 7.273-712.770).

CONCLUSIONS

Spectral CT imaging using quantitative analysis of the iodized oil retention in target HCCs can predict tumor responses after a conventional transarterial chemoembolization procedure.

Evaluation of liver tumour response by imaging

The goal of assessing tumour response on imaging is to identify patients who are likely to benefit - or not - from anticancer treatment, especially in relation to survival. The World Health Organization was the first to develop assessment criteria. This early score, which assessed tumour burden by standardising lesion size measurements, laid the groundwork for many of the criteria that followed. This was then improved by the Response Evaluation Criteria in Solid Tumours (RECIST) which was quickly adopted by the oncology community. At the same time, many interventional oncology treatments were developed to target specific features of liver tumours that result in significant changes in tumours but have little effect on tumour size. New criteria focusing on the viable part of tumours were therefore designed to provide more appropriate feedback to guide patient management. Targeted therapy has resulted in a breakthrough that challenges conventional response criteria due to the non-linear relationship between response and tumour size, requiring the development of methods that emphasize the appearance of tumours. More recently, research into functional and quantitative imaging has created new opportunities in liver imaging. These results have suggested that certain parameters could serve as early predictors of response or could predict later tumour response at baseline. These approaches have now been extended by machine learning and deep learning. This clinical review focuses on the progress made in the evaluation of liver tumours on imaging, discussing the rationale for this approach, addressing challenges and controversies in the field, and suggesting possible future developments.

Evaluation of transarterial chemoembolization refractoriness in patients with hepatocellular carcinoma

Background & aim

In clinical practice, transarterial chemoembolization (TACE) has been widely used for the treatment of hepatocellular carcinoma (HCC) beyond as well as within guideline recommendations. Here we aimed to verify whether two consecutive non-responses could be an optimal criterion for creating a rule to stop TACE being performed on these patients.

Methods

This study evaluated 200 patients with HCC beyond the Milan criteria, initially treated with TACE. TACE response was determined using the mRECIST criteria via dynamic CT or MRI. Median follow-up duration was 23.9 months.

Results

Within the 200 patients analyzed, 183 (91.5%) were male, with a total median age of 59.8 years. The mean size of the largest tumor was 6.8 cm, with 80 (40.0%) patients with ≥4 tumors. After the first TACE procedure, complete response, partial response, stable disease, or progressive disease were observed in 48 (24.0%), 87 (43.5%), 59 (29.5%) and 6 (3.0%) of patients, respectively. 45 (22.5%) patients showed no objective response (OR) following two consecutive TACE sessions. Of these, 28 received a subsequent TACE, with a 10.7% OR rate. Patients without OR showed poorer survival when compared to patients who achieved OR after repeated TACE. Multivariable analysis showed that size of the largest tumor >5cm and high alpha-fetoprotein of >200 ng/mL were significant factors associated with failure of OR to two consecutive TACE sessions.

Conclusion

Patients showing no OR to two consecutive TACE sessions will present a poor OR to subsequent TACE procedures. Early transition to systemic therapy may be advocated in such cases.

mRECIST for HCC: Performance and novel refinements

In 2010, modified RECIST (mRECIST) criteria were proposed as a way of adapting the RECIST criteria to the particularities of hepatocellular carcinoma (HCC). We intended to overcome some limitations of RECIST in measuring tumour shrinkage with local and systemic therapies, and also to refine the assessment of progression that could be misinterpreted with conventional RECIST 1.1, due to clinical events related to the natural progression of chronic liver disease (development of ascites, enlargement of lymph nodes, etc.). mRECIST has served its purpose since being adopted or included in clinical practice guidelines (European, American and Asian) for the management of HCC; it has also been instrumental for assessing response and time-to-event endpoints in several phase II and III investigations. Nowadays, mRECIST has become the standard tool for measurement of radiological endpoints at early/intermediate stages of HCC. At advanced stages, guidelines recommend both methods. mRECIST has been proven to capture higher objective response rates in tumours treated with molecular therapies and those responses have shown to be independently associated with better survival. With the advent of novel treatment approaches (i.e. immunotherapy) and combination therapies there is a need to further refine and clarify some concepts around the performance of mRECIST. Similarly, changes in the landscape of standard of care at advanced stages of the disease are pointing towards progression-free survival as a potential primary endpoint in some phase III investigations, as effective therapies applied beyond progression might mask overall survival results. Strict recommendations for adopting this endpoint have been reported. Overall, we review the performance of mRECIST during the last decade, incorporating novel clarifications and refinements in light of emerging challenges in the study and management of HCC.

Spectral CT Imaging-Based Quantification of Iodized Oil Retention following Chemoembolization: Phantom and Animal Studies

PURPOSE

To evaluate accuracy of iodine quantification using spectral CT and the potential of quantitative iodized oil analysis as an imaging biomarker of chemoembolization.

MATERIALS AND METHODS

A phantom of an artificial liver with 6 artificial tumors containing different amounts of iodized oil (0-8 vol%) was scanned by spectral CT, and iodized oil density (mg/mL) and Hounsfield unit (HU) values were measured. In addition, VX2 hepatoma was induced in 23 rabbits. After chemoembolization using iodized oil chemoemulsion, the rabbits were scanned by spectral CT. The accumulation of iodized oil in the tumor was quantified in terms of iodized oil density and HUs, and the performances in predicting a pathologic complete response (CR) were evaluated by receiver operating characteristic curve analyses.

RESULTS

The mean difference between true iodine densities and spectral image-based measurements was 0.5 mg/mL. Mean HU values were highly correlated with mean iodine density (r² = 1.000, P < .001). In the animal study, a pathologic CR was observed in 17 of 23 rabbits (73.9%). The range of area under the curve values of iodine and HU measurements was 0.863-0.882. A tumoral iodine density of 3.57 mg/mL, which corresponds to 0.7 vol% iodized oil in the tumor, predicted a pathologic CR with a sensitivity of 70.6% and a specificity of 100.0%.

CONCLUSIONS

Spectral CT imaging has a potential to predict tumor responses after chemoembolization by quantitatively assessing iodized oil in targets.

Lipiodol retention pattern after TACE for HCC is a predictor for local progression in lesions with complete response

Background

To evaluate the predictive value of the lipiodol retention pattern for local progression of HCC with a complete response (CR) on CT according to mRECIST criteria after a first session of conventional chemoembolization (cTACE).

Methods

From January 2014 to May 2016 all consecutive patients undergoing a first cTACE session for HCC were identified. Inclusion criteria were the presence of ≤3 HCCs and available pre- and post-cTACE CT. Tumor response was classified according to mRECIST criteria. The analysis focused on tumors with a CR. The lipiodol retention pattern in these tumors was classified as complete (C-Lip, covering the entire tumor volume), or incomplete (I-Lip). Local progression was defined as the reappearance of areas of enhancement on arterial-phase images with washout on portal/delayed phase images within 2 cm from treated tumors on follow-up CT.

Results

The final population included 50 patients with 82 HCCs. A total of 46 (56%) HCCs were classified with a CR, including 16 (35%) with I-Lip, and 30 (65%) with C-Lip. After a median follow-up of 14 months (3.2–35.9 months), 15/16 (94%) and 10/30 (30%) of I-Lip and C-Lip HCCs showed local progression on CT, respectively (p < 0.001), with no significant difference in the time to progression (mean 11.1 ± 2 vs. 13.4 ± 3 months for I-Lip and C-Lip, respectively p = 0.51).

Conclusions

HCCs with incomplete lipiodol retention after a first cTACE session have a high risk of local progression even when there is a CR according to mRECIST, and should be considered to be incompletely treated.

Radiological appearance of hepatocellular carcinoma predicts the response to trans-arterial chemoembolization in patients undergoing liver transplantation

Background

The ultimate goal of locoregional therapy (LRT) to the liver is to induce total tumor necrosis. Trans-arterial chemoembolization (TACE) is the mainstay bridging therapy for patients with hepatocellular carcinoma (HCC) waiting for liver transplantation (LT). However, tumor response rate is variable. The purpose of this study was to correlate HCC radiological appearance with level of tumor necrosis during explant analysis from patients undergoing LT who received pre-LT TACE.

Methods

From January 2000 to December 2018, a total of 66 patients with HCC who had been treated prior to LT by means of TACE were analyzed. Diagnosis of HCC was made based on AASLD guidelines and confirmed via histopathology explant analysis. Radiologic tumor response after TACE was based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). Degree of tumor necrosis was determined by histopathology analysis of liver explants. HCC radiological appearances on CT before TACE were assessed and correlated with histological findings after LT.

Results

Eighty nine TACE procedures (1.35 ± 0.67; 1–4) were performed, of which 18 were repeated TACE (27.3%) procedures. In 56.1% of the patients, ≥90% (near-complete) tumor necrosis was achieved. Concordance between mRECIST criteria and pathology was observed in 63% of the patients, with an underestimation of tumor response in 18 (27%) patients and an overestimation in 6 (9.1%). Near-complete tumor necrosis upon pathological analysis was associated with tumor hyper-enhancement in the arterial phase (P = 0.002), “typical tumor enhancement” (P = 0.010) and smooth tumor margins (p = 0.011). The multivariate analysis showed that well circumscribed HCCs with smooth margins and arterial hyper-enhancement independently correlated with post-TACE near-complete histological tumor necrosis.

Conclusions

The well circumscribed HCC lesions with arterial hyper-enhancement are more susceptible to TACE than lesions with arterial phase iso or hypo-enhancement and lesions with infiltrative appearance. Pre-TACE CT imaging may ease the selection of an optimal treatment strategy for bridging patients with HCC to liver transplantation.

The clinical behavior and survival of patients with hepatocellular carcinoma and a family history of the disease

Purpose

Familial clustering is a common feature of hepatocellular carcinoma (HCC) as well as a risk factor for the disease. We aimed to assess whether such a family history affected prognostic outcomes in patients with HCC diagnosed at different stages of the disease.

Materials/Methods

This hospital registry‐based cohort study included 5484 patients initially diagnosed with HCC. Individual family histories of cancer were obtained by interview and reported by trained nurses who constructed three‐generation pedigrees. Overall survival data were compared between cases with and without first‐degree relatives affected by HCC, with adjustment for other potential predictors.

Results

Of 5484 patients, 845 (15.4%) had first‐degree relatives with a history of HCC. Family history was associated with longer survival in the entire cohort (adjusted hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.80‐0.98, P = .025). A significant trend for reduced risk of death with increasing number of affected family members was also observed (P for trend = 0.018). The stage‐stratified analysis showed that the presence of family history was especially associated with a reduced risk of death in the subset of patients with HCC at a (very) early stage (adjusted HR 0.83, 95% CI 0.69‐0.99; P = .042). The proportion of cases receiving curative treatment was also higher in early‐stage patients with a family history (72.6% vs 63.3%; P < .001).

Conclusions

A first‐degree family history of the disease is a prognostic factor for improved survival in patients with HCC, especially in those whose tumors can be cured by radical treatments.

Evaluation of treatment response in hepatocellular carcinoma in the explanted liver with Liver Imaging Reporting and Data System version 2017

OBJECTIVE

To investigate the performance of Liver Imaging Reporting and Data System (LI-RADS) v2017 treatment response algorithm for predicting hepatocellular carcinoma (HCC) viability after locoregional therapy (LRT) using the liver explant as reference.

METHODS

One hundred fourteen patients with 206 HCCs who underwent liver transplantation (LT) after LRT for HCCs were included in this retrospective study. Two radiologists independently evaluated tumor viability using the LI-RADS and modified RECIST (mRECIST) with CT and MRI, respectively. The sensitivity and specificity of arterial phase hyperenhancement (APHE) and LR-TR viable criteria (any of three findings: APHE, washout, and enhancement pattern similar to pretreatment imaging) were compared using logistic regression. Receiver operating characteristics (ROC) analysis was used to compare the diagnostic performance between LI-RADS and mRECIST and between CT and MRI.

RESULTS

The sensitivity and specificity for diagnosing viable tumor were not significantly different between APHE alone and LR-TR viable criteria on CT (p = 0.054 and p = 0.317) and MRI (p = 0.093 and p = 0.603). On CT, the area under the ROC curve (AUC) of LI-RADS was significantly higher than that of mRECIST (0.733 vs. 0.657, p < 0.001). On MRI, there was no significant difference in AUCs between LI-RADS and mRECIST (0.802 vs. 0.791, p = 0.500). Intra-individual comparison of CT and MRI showed comparable AUCs using LI-RADS (0.783 vs. 0.795, p = 0.776).

CONCLUSIONS

LI-RADS v2017 treatment response algorithm showed better diagnostic performance than mRECIST on CT. With LI-RADS, CT and MRI were comparable to diagnose tumor viability of HCC after LRT.

KEY POINTS

• Using Liver Imaging Reporting and Data System (LI-RADS) v2017 treatment response algorithm, the viability of hepatocellular carcinoma (HCC) after locoregional therapy (LRT) can be accurately diagnosed. • LI-RADS v2017 treatment response algorithm is superior to modified Response Evaluation Criteria in Solid Tumors for evaluating HCC viability using CT. • Either CT or MRI can be performed to assess tumor viability after LRT using LI-RADS v2017 treatment response algorithm.

Reproducibility of mRECIST in Measurement and Response Assessment for Hepatocellular Carcinoma Treated by Transarterial Chemoembolization

RATIONALE AND OBJECTIVES

To evaluate the reproducibility of Modified Response Evaluation Criteria in Solid Tumors (mRECIST) for hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) using multiphasic computed tomography.

MATERIALS AND METHODS

The institutional review board approved this retrospective study. We evaluated 97 patients who underwent TACE (60 conventional TACE [cTACE] and 37 drug-eluting bead TACE [DEB-TACE]) for HCC from 2010 to 2014. Four radiologists evaluated pairs of dynamic liver CTs scanned within 2 months before and after TACE based on mRECIST. Assessment of intra- or interobserver reproducibility for response categorization and sum of long diameter were evaluated using weighted kappa statistics (κ) and intraclass correlation coefficients, respectively. The relationship between concordance of target lesion selection and agreement of target lesion response was evaluated using Fisher exact test.

RESULTS

Intraobserver reproducibility for overall response was moderate to excellent (κ = 0.525-0.865). Interobserver reproducibility was improved on the second review compared to the first review and it was good in both treatment groups (κ = 0.627 for cTACE and 0.602 for DEB-TACE). Between the two treatment methods, intra- or interobserver reproducibility was better after cTACE than DEB-TACE. Intraclass correlation coefficients for sum of long diameter measurement showed excellent intra- or interobserver reproducibility. The concordance rate of target lesion selection was significantly higher for patients with radiologists' agreement for target lesion response than patients with disagreed response (P = .003).

CONCLUSIONS

The intra- and interobserver reproducibility of mRECIST in patients with HCC after TACE was moderate to excellent, and the reproducibility was slightly better after cTACE than DEB-TACE.

Radiological response and inflammation scores predict tumour recurrence in patients treated with transarterial chemoembolization before liver transplantation

AIM

To investigate the prognostic value of the radiological response after transarterial chemoembolization (TACE) and inflammatory markers in patients affected by hepatocellular carcinoma (HCC) awaiting liver transplantation (LT).

METHODS

We retrospectively evaluated the preoperative predictors of HCC recurrence in 70 patients treated with conventional (n = 16) or doxorubicin-eluting bead TACE (n = 54) before LT. The patient and tumour characteristics, including the static and dynamic alpha-fetoprotein, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) measurements, were recorded. Treatment response was classified according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST) and the European Association for the Study of the Liver (EASL) criteria as complete response (CR), partial response (PR), stable disease or progressive disease. After examination of the explanted livers, histological necrosis was classified as complete (100% of the cumulative tumour area), partial (50%-99%) or minimal (< 50%) and was correlated with the preoperative radiological findings.

RESULTS

According to the pre-TACE radiological evaluation, 22/70 (31.4%) and 12/70 (17.1%) patients were beyond Milan and University of San Francisco (UCSF) criteria, respectively. After TACE procedures, the objective response (CR + PR) rates were 71.4% and 70.0% according to mRECIST and EASL criteria, respectively. The agreement between the two guidelines in defining the radiological response was rated as very good both for the overall and target lesion response (weighted k-value: 0.98 and 0.93, respectively). Complete and partial histological necrosis were achieved in 14/70 (20.0%) and 28/70 (40.0%) patients, respectively. Using histopathology as the reference standard, mRECIST criteria correctly classified necrosis in 72.9% (51/70) of patients and EASL criteria in 68.6% (48/70) of cases. The mRECIST non-response to TACE [Exp(b) = 9.2, p = 0.012], exceeding UCSF criteria before TACE [Exp(b) = 4.7, p = 0.033] and a preoperative PLR > 150 [Exp(b) = 5.9, p = 0.046] were independent predictors of tumour recurrence.

CONCLUSION

The radiological response and inflammatory markers are predictive of tumour recurrence and allow the proper selection of TACE-treated candidates for LT.

Clinical validity of Metroticket calculator in transplant patients undergoing prior chemoembolization for hepatocellular carcinoma

AIM

To test the predictive performance of the Metroticket calculator for survival after liver transplantation (LT) of patients with hepatocellular carcinoma (HCC) undergoing prior transarterial chemoembolization (TACE).

METHODS

A total of 142 patients treated with TACE and subsequent LT who had arterial enhancing HCC(s) were entered into this analysis. Tumor parameters measured by the enhancement radiological method pre-LT or by pathology post-LT were incorporated into the Metroticket analysis. The calculator was validated in terms of calibration and discrimination capacity.

RESULTS

Mean 3- and 5-year survival rates predicted in the radiological model for all 142 patients were 76.4 and 70.1 %, respectively, lying comfortably within the 95 % confidence interval (CI) of the observed survival rate estimates (72.8-86.2 and 68.6-83.2 %, respectively). In the pathological model incorporating microvascular invasion, the mean anticipated survival rate at 5 years of 120 patients with viable nodules on explants was 69.5 %, also lying inside the 95 % CI of the actuarial rates (67.9-83.5 %). The c-indices as measures of discriminatory power were 0.61 and 0.62, respectively, for the 3- and 5-year predictions in the radiological model, and 0.72 for the 5-year prediction in the pathological model. The corresponding findings were similar for subgroups with hepatitis B virus infection and undergoing living-donor LT.

CONCLUSIONS

The Metroticket calculation based on explant data accurately predicts post-LT survival of HCC patients with prior TACE. Imaging estimate-based predictions before LT appear to provide poorer discrimination than calibration.

Intra-arterial therapies for liver cancer: assessing tumor response

INTRODUCTION

Intra-arterial therapies (IATs) play an integral role in the management of unresectable hepatocellular carcinoma and liver metastases. The ability to accurately assess tumor response to intra-arterial therapies is crucial for clinical management. Several one- and two-dimensional manual imaging-based response assessment techniques, based both on tumor size or enhancement, have shown to be highly subjective and merely surrogate for the actual tumor as a whole. Areas covered: Given the currently existing literature, we will discuss all available tumor assessment techniques and criteria for liver cancer with a strong emphasis on 3D quantitative imaging biomarkers of tumor response in this review. Expert commentary: The growing role of information technology in medicine has brought about the advent of software-assisted, segmentation-based assessment techniques that address the outstanding issues of a subjective reader and provide for more accurate assessment techniques for the locally treated lesions. Three-dimensional quantitative tumor assessment techniques are superior to one- and two-dimensional measurements. This allows for treatment alterations and more precise targeting, potentially resulting in improved patient outcome.

Correlation of tumor response on computed tomography with pathological necrosis in hepatocellular carcinoma treated by chemoembolization before liver transplantation

The purpose of this article was to compare the results of Response Evaluation Criteria in Solid Tumors (RECIST), modified Response Evaluation Criteria in Solid Tumors (mRECIST), and European Association for the Study of the Liver (EASL) criteria for the evaluation of tumor necrosis in patients treated with transarterial chemoembolization before liver transplantation (LT) for hepatocellular carcinoma. Response to treatment was evaluated on computed tomography scan by 2 independent readers based on RECIST, mRECIST, and EASL criteria, and compared with tumor necrosis assessed by explant pathology. Necrosis was defined as major when >90%. Factors associated with major necrosis were tested by multivariate analysis. Fifty-eight patients (53 males; mean age, 54 years; range, 31-64 years) were included with 88 nodules. Fifty-one (58%) nodules were shown to have major necrosis. Among them readers 1 and 2 identified a complete response (CR) according to RECIST, mRECIST, and EASL criteria in 2 (4%), 47 (92%), and 47 (92%), and 1 (2%), 45 (88%), and 45 (88%) nodules, respectively. However, 12-14 of 59 nodules classified as CR on mRECIST or EASL criteria were found to have intermediate or minor necrosis (overestimation in 20%-24% of the patients). Combining the classification of CR by mRECIST and EASL criteria and complete lipiodol deposition reduced the overestimation to 11%. Among 59 nodules classified with a CR according to mRECIST or EASL, those with complete lipiodol deposition (n = 36, 61%) had a higher rate of necrosis than those with incomplete lipiodol deposition (n = 23, 39%): 95% versus 68% and 95% versus 63% for reader 1 and 2, respectively. In conclusion, CR based on mRECIST/EASL combined with complete lipiodol deposition was better for identification of major tumor necrosis. Even in the presence of CR according to mRECIST/EASL, incomplete lipiodol deposition should be considered indicative of substantial viable tumor remnant. Liver Transplantation 22 1491-1500 2016 AASLD.

Does the Degree of Hepatocellular Carcinoma Tumor Necrosis following Transarterial Chemoembolization Impact Patient Survival?

Purpose. The association between transarterial chemoembolization- (TACE-) induced HCC tumor necrosis measured by the modified Response Evaluation Criteria In Solid Tumors (mRECIST) and patient survival is poorly defined. We hypothesize that survival will be superior in HCC patients with increased TACE-induced tumor necrosis. Materials and Methods. TACE interventions were retrospectively reviewed. Tumor response was quantified via dichotomized (responders and nonresponders) and the four defined mRECIST categories. Results. Median survival following TACE was significantly greater in responders compared to nonresponders (20.8 months versus 14.9 months, p = 0.011). Survival outcomes also significantly varied among the four mRECIST categories (p = 0.0003): complete, 21.4 months; partial, 20.8; stable, 16.8; and progressive, 7.73. Only progressive disease demonstrated significantly worse survival when compared to complete response. Multivariable analysis showed that progressive disease, increasing total tumor diameter, and non-Child-Pugh class A were independent predictors of post-TACE mortality. Conclusions. Both dichotomized (responders and nonresponders) and the four defined mRECIST responses to TACE in patients with HCC were predictive of survival. The main driver of the survival analysis was poor survival in the progressive disease group. Surprisingly, there was small nonsignificant survival benefit between complete, partial, and stable disease groups. These findings may inform HCC treatment decisions following first TACE.

Optimal methods for measuring eligibility for liver transplant in hepatocellular carcinoma patients undergoing transarterial chemoembolization

BACKGROUND & AIMS

We investigated the optimal radiologic method for measuring hepatocellular carcinoma (HCC) treated by transarterial chemoembolization (TACE) in order to assess suitability for liver transplantation (LT).

METHODS

271 HCC patients undergoing TACE prior to LT were classified according to both Milan and up-to-seven criteria after TACE by using the enhancement or size method on computed tomography images. The cumulative incidence function curves with competing risks regression was used in post-LT time-to-recurrence analysis. The predictive accuracy for recurrence was compared using area under the time-dependent receiver operating characteristic curves (AUC) estimation.

RESULTS

Of the 271 patients, 246 (90.8%) and 164 (60.5%) fell within Milan and 252 (93.0%) and 210 (77.5%) fell within up-to-seven criteria, when assessed by enhancement and size methods, respectively. Competing risks regression analyses adjusting for covariates indicated that meeting the criteria by enhancement and by size methods was independently related to post-LT time-to-recurrence in the Milan or up-to-seven model. Higher AUC values were observed with the size method only in the up-to-seven model (p<0.05). Mean differences in the sum of tumor diameter and number of tumors between pathologic and radiologic findings were significantly less by the enhancement method (p<0.05). Cumulative incidence curves showed similar recurrence results between patients with and without prior TACE within the criteria based on either method, except for the within up-to-seven by the enhancement method (p=0.017).

CONCLUSIONS

The enhancement method is a reliable tool for assessing the control or downstaging of HCC within Milan after TACE, although the size method may be preferable when applying the up-to-seven criterion.

Radiologic-pathologic analysis of contrast-enhanced and diffusion-weighted MR imaging in patients with HCC after TACE: diagnostic accuracy of 3D quantitative image analysis

PURPOSE

To evaluate the diagnostic performance of three-dimensional ( 3D three-dimensional ) quantitative enhancement-based and diffusion-weighted volumetric magnetic resonance (MR) imaging assessment of hepatocellular carcinoma ( HCC hepatocellular carcinoma ) lesions in determining the extent of pathologic tumor necrosis after transarterial chemoembolization ( TACE transarterial chemoembolization ).

MATERIALS AND METHODS

This institutional review board-approved retrospective study included 17 patients with HCC hepatocellular carcinoma who underwent TACE transarterial chemoembolization before surgery. Semiautomatic 3D three-dimensional volumetric segmentation of target lesions was performed at the last MR examination before orthotopic liver transplantation or surgical resection. The amount of necrotic tumor tissue on contrast material-enhanced arterial phase MR images and the amount of diffusion-restricted tumor tissue on apparent diffusion coefficient ( ADC apparent diffusion coefficient ) maps were expressed as a percentage of the total tumor volume. Visual assessment of the extent of tumor necrosis and tumor response according to European Association for the Study of the Liver ( EASL European Association for the Study of the Liver ) criteria was performed. Pathologic tumor necrosis was quantified by using slide-by-slide segmentation. Correlation analysis was performed to evaluate the predictive values of the radiologic techniques.

RESULTS

At histopathologic examination, the mean percentage of tumor necrosis was 70% (range, 10%-100%). Both 3D three-dimensional quantitative techniques demonstrated a strong correlation with tumor necrosis at pathologic examination (R(2) = 0.9657 and R(2) = 0.9662 for quantitative EASL European Association for the Study of the Liver and quantitative ADC apparent diffusion coefficient , respectively) and a strong intermethod agreement (R(2) = 0.9585). Both methods showed a significantly lower discrepancy with pathologically measured necrosis (residual standard error [ RSE residual standard error ] = 6.38 and 6.33 for quantitative EASL European Association for the Study of the Liver and quantitative ADC apparent diffusion coefficient , respectively), when compared with non- 3D three-dimensional techniques ( RSE residual standard error = 12.18 for visual assessment).

CONCLUSION

This radiologic-pathologic correlation study demonstrates the diagnostic accuracy of 3D three-dimensional quantitative MR imaging techniques in identifying pathologically measured tumor necrosis in HCC hepatocellular carcinoma lesions treated with TACE transarterial chemoembolization .

Assessing tumor response after loco-regional liver cancer therapies: the role of 3D MRI

Assessing the tumor response of liver cancer lesions after intraarterial therapies is of major clinical interest. Over the last two decades, tumor response criteria have come a long way from purely size-based, anatomic methods such as the Response Evaluation Criteria in Solid Tumors towards more functional, enhancement- and diffusion-based parameters with a strong emphasis on MRI as the ultimate imaging modality. However, the relatively low reproducibility of those one- and 2D techniques (modified Response Evaluation Criteria in Solid Tumors and the European Association for the Study of the Liver criteria) provided the rationale for the development of new, 3D quantitative assessment techniques. This review will summarize and compare the existing methodologies used for 3D quantitative tumor analysis and provide an overview of the published clinical evidence for the benefits of 3D quantitative tumor response assessment techniques.

Clinical significance of the best response during repeated transarterial chemoembolization in the treatment of hepatocellular carcinoma

BACKGROUND & AIMS

We assessed the clinical implications of the best response compared with the initial response during repeated transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).

METHODS

We evaluated 332 patients with intermediate-stage HCC and preserved liver function initially treated with repeated TACE. All had ≥1 lesion measuring ≥1 cm, and the response measured after each session was based on EASL and mRECIST criteria. We performed survival analyses according to response kinetics, and identified clinical factors associated with the need for repeated TACE to achieve the best response.

RESULTS

An objective response, either a complete response (CR) or a partial response (PR), after the first TACE was seen in about 50% of patients by both EASL and mRECIST. In terms of the best response during serial TACE, 250 patients (75.3%) by EASL and 278 (83.7%) by mRECIST were overall responders. The sizes of the largest and second largest tumors were the only parameters positively correlated with the number of TACE sessions required to achieve the best response (p<0.05). Multivariate Cox analysis showed that achieving a CR or PR as the best response was the best predictor of survival following TACE with a hazard ratio of 0.45 by EASL and 0.24 by mRECIST, and more than 0.69 and 0.71, respectively for initial responders (p<0.05).

CONCLUSIONS

The best response observed during serial TACE, rather than the initial response, most strongly predicts the survival of patients with intermediate-stage HCC. The number of TACE sessions needed to achieve a best response is a function of tumor size.

Radiological-pathological analysis of WHO, RECIST, EASL, mRECIST and DWI: Imaging analysis from a prospective randomized trial of Y90 ± sorafenib

The aim of this study was to compare radiological and pathological changes and test the adjunct efficacy of Sorafenib to Y90 as a bridge to transplantation in hepatocellular carcinoma (HCC). 15 patients with 16 HCC lesions were randomized to Y90 without (Group A, n = 9) or with Sorafenib (Group B, n = 7). Size (WHO, RECIST), enhancement (EASL, mRECIST) and diffusion-weighted imaging criteria (apparent diffusion coefficient, ADC) measurements were obtained at baseline, then at 1 and every 3 months after treatment until transplantation. Percentage necrosis in explanted tumors was correlated with imaging findings. 100%, 50%-99% and <50% pathological necrosis was observed in 6 (67%), 1 (11%), and 2 (22%) tumors in Group A and 3 (42%), 2 (28%), and 2 (28%) in Group B, respectively (P = 0.81). While ADC (P = 0.46) did not change after treatment, WHO (P = 0.06) and RECIST (P = 0.08) response at 1 month failed to reach significance, but significant responses by EASL (P < 0.01/0.03) and mRECIST (P < 0.01/0.03) at 1 and 3 months were observed. Response was equivalent by EASL or mRECIST. No difference in response rates was observed between groups A and B at 1 and 3 months by WHO, RECIST, EASL, mRECIST or ADC measurements. Despite failing to reach significance, smaller baseline size was associated with complete pathological necrosis (CPN) (RECIST: P = 0.07; WHO: P = 0.05). However, a cut-off size of 35 mm was predictive of CPN (P = 0.005). CPN could not be predicted by WHO (P = 0.25 and 0.62), RECIST (P = 0.35 and 0.54), EASL (P = 0.49 and 0.46), mRECIST (P = 0.49 and 0.60) or ADC (P = 0.86 and 0.93).

CONCLUSION

The adjunct of Sorafenib did not augment radiological or pathological response to Y90 therapy for HCC. Equivalent significant reduction in enhancement at 1 and 3 months by EASL/mRECIST was noted. Neither EASL nor mRECIST could reliably predict CPN.