Data System Treatment Response Research Articles

Reassessment After Locoregional Treatment of Hepatocellular Carcinoma Previous Liver Transplantation: Is MRI Necessary for All Patients?

The tumor response of cirrhotic patients with hepatocellular carcinoma (HCC) undergoing locoregional treatment (TLR) before liver transplantation can be evaluated using different imaging tests. The aim of this study was to compare the correlation of radiological response evaluated by magnetic resonance imaging (MRI) vs computed tomography (CT) vs ultrasound with histopathological findings. A retrospective single-center study was performed. Data of patients undergoing Liver transplantation due to HCC between January 2010 and December were collected, selecting patients who underwent TLR. Four hundred and four patients were transplanted, of whom 103 (25.5%) had HCC. Ninety-seven patients (93.2%) received TLR. Eighty-eight of these patients (90.7%) underwent a reevaluation imaging test: 8 (8.2%) underwent ultrasound, 68 (70.1%) underwent MRI, and 12 (12.4%) underwent CT. Of the 88 patients, 59% were classified as nonviable LR-TR (Liver Imaging Reporting and Data System Treatment Response), 32.5% as viable LR-TR, and the rest (8.5%) as equivocal LR-TR. Regarding the correlation of the degree of radiological response according to each imaging test, ultrasound categorized 62.5% as nonviable LR-TR vs 60.6% by MRI vs 44.4% by CT, with these differences not being significant (P=.779). Regarding the correlation of patients classified as nonviable LR-TR by each test and total tumor necrosis in histopathology, both MRI and ultrasound correctly classified 60% of complete necrosis as nonviable LR-TR, and in the case of CT, it was 50%, with these differences not being significant (P=1). Ultrasound and CT have obtained similar results as reevaluation tests to MRI, which could replace it in case of unavailability of the latter.

Role of contrast-enhanced ultrasound with Perfluorobutane in lesion detection, guidance for microwave ablation, and response assessment of hepatocellular carcinoma.

To evaluate role of perfluorobutane in guiding microwave ablation of HCC and to compare treatment response at 3h of ablation using contrast-enhanced US (CEUS) with Sonazoid with 1-month follow-up contrast-enhanced CT/MRI. This was a single center prospective study and consecutive patients planned for microwave ablation of HCC from October to November 2021 were enrolled. Pre-procedure CEUS were performed using Sonazoid in both vascular and Kupffer phase and number of Kupffer defects compared with gray scale US. Precise needle placement of microwave applicator was done in the Kupffer phase. 3hours post ablation CEUS was repeated to evaluate response assessment using Liver Imaging Reporting and Data System Treatment Response criteria (LR TR). One-month follow-up imaging was done using multiphasic CECT/dynamic CEMRI and comparison was done with post procedure CEUS.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 5 Given name: [Manoj Kumar] Last name [Sharma]. Author 6 Given name: [Shiv Kumar] Last name [Sarin]. Also, kindly confirm the details in the metadata are correct. all the names and affiliations are correct RESULTS: A total of 26 patients (24 males and 2 females, mean age 61.38 ± 9.76years) having 40 lesions, of mean tumor diameter 21.4 ± 7.7mm, underwent CEUS and ablation. Most common etiology for cirrhosis was viral hepatitis, followed by non-alcoholic steatohepatitis (NASH). Four (10%) additional lesions (which were seen on pre-procedure imaging) were detected in Kupffer phase over gray scale US. All lesions showed complete response in the immediate post procedure CEUS. Technique efficacy at 1-month was 95% according to the LR TR criteria.Please check the edit made in article title and amend if necessary.The edit is correct and appropriatePlease check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.All the names and their respective affiliations are correct CONCLUSION: CEUS with Sonazoid is an excellent modality for precise needle placement for ablation due to stable nature and excellent lesion visibility of Kupffer phase.

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

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

Liver Imaging-Reporting and Data System treatment response algorithm predicts postsurgical recurrence in locoregional therapy-treated hepatocellular carcinoma.

In HCC, locoregional therapy (LRT) is performed as a bridging or downstaging treatment before curative surgery. The impact of the LI-RADS Treatment Response (LR-TR) algorithm on surgical outcomes remains unknown. We aimed to evaluate radiologic and clinical factors predicting recurrence-free survival (RFS) and overall survival (OS) after curative surgery for LRT-treated HCC. Consecutive HCC patients who underwent liver transplantation or curative resection after LRT from 2010 to 2016 and had baseline and follow-up post-LRT CT/MRI up to the point of surgery were included. The LR-TR category at the time of surgery and other features were assessed using Cox proportional hazard models. RFS was estimated and compared using the Kaplan-Meier method with log-rank tests. We evaluated 73 patients with 115 lesions. The LR-TR viable category at the time of surgery (hazard ratio [HR], 3.84; 95% confidence interval [CI]: 1.04, 14.16), preoperative AFP > 200 ng/mL (HR, 3.63; 95% CI: 1.63, 8.10), LRT sessions > 3 (HR, 4.99; 95% CI: 1.73, 14.38), and resection (HR, 3.35; 95% CI: 1.39, 8.09) independently predicted recurrence. The risk score categorized the patients into poor, intermediate, and favorable-risk groups with 1-year RFS rates of 35.0%, 78.3%, and 97.0%, respectively (p < 0.001). Outside Milan at the time of surgery (HR, 5.79; 95% CI: 1.94, 17.07) and recurrence within the first postoperative year (HR, 17.66; 95% CI: 6.42, 48.56) predicted death. In LRT-treated HCC, non-LR-TR viable disease achieved within fewer LRT sessions and removed by liver transplantation recurred less. • The Liver Imaging Reporting and Data System treatment response (LR-TR) viable disease (hazard ratio [HR], 3.84; p = 0.043), preoperative serum AFP level > 200 ng/mL (HR, 3.63; p = 0.002), more than three locoregional treatment (LRT) sessions (HR, 4.99; p = 0.003), and resection compared to liver transplantation (HR, 3.35; p = 0.001) were the independent predictors for postsurgical recurrence in LRT-treated HCCs. • A scoring system combining LR-TR categories and key clinical factors stratifies the patients into poor, intermediate, and favorable recurrence risk groups, with 1-year RFS rates of 35.0%, 78.3%, and 97.0%, respectively (p < 0.001). • Outside Milan at the time of surgery (HR, 5.79; p = 0.001) and recurrence within the first postoperative year (HR, 17.66; p < 0.001) were associated with poor overall survival.

LI-RADS Treatment Response versus Modified RECIST for Diagnosing Viable Hepatocellular Carcinoma after Locoregional Therapy: A Systematic Review and Meta-Analysis of Comparative Studies.

PurposeTo systematically compare the performance of liver imaging reporting and data system treatment response (LR-TR) with the modified Response Evaluation Criteria in Solid Tumors (mRECIST) for diagnosing viable hepatocellular carcinoma (HCC) treated with locoregional therapy (LRT).Materials and MethodsOriginal studies of intra-individual comparisons between the diagnostic performance of LR-TR and mRECIST using dynamic contrast-enhanced CT or MRI were searched in MEDLINE and EMBASE, up to August 25, 2021. The reference standard for tumor viability was surgical pathology. The meta-analytic pooled sensitivity and specificity of the viable category using each criterion were calculated using a bivariate random-effects model and compared using bivariate meta-regression.ResultsFor five eligible studies (430 patients with 631 treated observations), the pooled per-lesion sensitivities and specificities were 58% (95% confidence interval [CI], 45%–70%) and 93% (95% CI, 88%–96%) for the LR-TR viable category and 56% (95% CI, 42%–69%) and 86% (95% CI, 72%–94%) for the mRECIST viable category, respectively. The LR-TR viable category provided significantly higher pooled specificity (p < 0.01) than the mRECIST but comparable pooled sensitivity (p = 0.53).ConclusionThe LR-TR algorithm demonstrated better specificity than mRECIST, without a significant difference in sensitivity for the diagnosis of pathologically viable HCC after LRT.

Artificial intelligence in assessment of hepatocellular carcinoma treatment response.

Artificial Intelligence (AI) continues to shape the practice of radiology, with imaging of hepatocellular carcinoma (HCC) being of no exception. This article prepared by members of the LI-RADS Treatment Response (TR LI-RADS) work group and associates, presents recent trends in the utility of AI applications for the volumetric evaluation and assessment of HCC treatment response. Various topics including radiomics, prognostic imaging findings, and locoregional therapy (LRT) specific issues will be discussed in the framework of HCC treatment response classification systems with focus on the Liver Reporting and Data System treatment response algorithm (LI-RADS TRA).

Performance of initial LI-RADS 2018 treatment response in predicting survival of patients with hepatocellular carcinoma following TACE: a retrospective, single-center cohort study

PurposeTreatment response following transarterial chemoembolization (TACE) is frequently evaluated with Liver Imaging Reporting and Data System Treatment Response (LR-TR) algorithm, but its association with patients’ outcomes is not supported in the literature. The purpose of this study was to provide such data.MethodsA retrospective analysis of 99 TACE patients with stage A/B hepatocellular carcinoma according to Barcelona-Clinic Liver Cancer staging system was performed. Two radiologists assessed LR-TR, while a third radiologist re-assessed divergent results. Overall survival (OS) and time to disease progression (TTP) were the primary endpoints of the study, while the Cox proportional hazard model was used for outcome analyses.ResultsInterobserver agreement was substantial between the two readers with κ = 0.69 (95% CI 0.58–0.81). The median OS in viable, equivocal, and non-viable groups were 27, 27, and 73 months, respectively (p < 0.001). However, after adjustment for confounding factors, there was no significant association between initial viable response and OS (HR 0.98 [95% CI 0.37–2.63], p = 0.97), while equivocal response remained statistically significant (HR 3.52. [95% CI 1.27–9.71], p = 0.015). No significant association was noted when viable and equivocal groups were analyzed in aggregate (HR 1.03 [95% CI 0.4–2.4], p = 0.96). The median TTP did not differ between non-viable and viable groups (23 vs 18 months, respectively; p = 0.98). None of the analyzed predictors was associated with TTP.ConclusionInitial LR-TR response was not an independent predictor for OS nor TTP. The preliminary results suggest the necessity for more aggressive management of equivocal patients.

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.

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). 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. 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). 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. • 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).

Usefulness of Arterial Subtraction in Applying Liver Imaging Reporting and Data System (LI-RADS) Treatment Response Algorithm to Gadoxetic Acid-Enhanced MRI.

ObjectiveWe aimed to evaluate the usefulness of arterial subtraction images for predicting the viability of hepatocellular carcinoma (HCC) after locoregional therapy (LRT) using gadoxetic acid-enhanced MRI and the Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm.Materials and MethodsThis study included 90 patients (mean age ± standard deviation, 57 ± 9 years) who underwent liver transplantation or resection after LRT and had 73 viable and 32 nonviable HCCs. All patients underwent gadoxetic acid-enhanced MRI before surgery. Two radiologists assessed the presence of LR-TR features, including arterial phase hyperenhancement (APHE) and LR-TR categories (viable, nonviable, or equivocal), using ordinary arterial-phase and arterial subtraction images. The reference standard for tumor viability was surgical pathology. The sensitivity of APHE for diagnosing viable HCC was compared between ordinary arterial-phase and arterial subtraction images. The sensitivity and specificity of the LR-TR algorithm for diagnosing viable HCC was compared between the use of ordinary arterial-phase and the use of arterial subtraction images. Subgroup analysis was performed on lesions treated with transarterial chemoembolization (TACE) only.ResultsThe sensitivity of APHE for viable HCCs was higher for arterial subtraction images than ordinary arterial-phase images (71.2% vs. 47.9%; p < 0.001). LR-TR viable category with the use of arterial subtraction images compared with ordinary arterial-phase images showed a significant increase in sensitivity (76.7% [56/73] vs. 63.0% [46/73]; p = 0.002) without significant decrease in specificity (90.6% [29/32] vs. 93.8% [30/32]; p > 0.999). In a subgroup of 63 lesions treated with TACE only, the use of arterial subtraction images showed a significant increase in sensitivity (81.4% [35/43] vs. 67.4% [29/43]; p = 0.031) without significant decrease in specificity (85.0% [17/20] vs. 90.0% [18/20]; p > 0.999).ConclusionUse of arterial subtraction images compared with ordinary arterial-phase images improved the sensitivity while maintaining specificity for diagnosing viable HCC after LRT using gadoxetic acid-enhanced MRI and the LR-TR algorithm.

Prediction of overall survival in patients with hepatocellular carcinoma treated with Y-90 radioembolization by imaging response criteria

PurposeTo evaluate the potential of imaging criteria in predicting overall survival of patients with hepatocellular carcinoma (HCC) after a first transcatheter arterial yttrium-90 radioembolization (TARE) Materials and methodsFrom October 2013 to July 2017, 37 patients with HCC were retrospectively included. There were 34 men and 3 women with a mean age of 60.5±10.2 (SD) years (range: 32.7–78.9 years). Twenty-five patients (68%) were Barcelona Clinic Liver Cancer (BCLC) C and 12 (32%) were BCLC B. Twenty-four primary index tumors (65%) were>5cm. Three radiologists evaluated tumor response on pre- and 4–7 months post-TARE magnetic resonance imaging or computed tomography examinations, using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, modified RECIST (mRECIST), European Association for Study of the Liver (EASL), volumetric RECIST (vRECIST), quantitative EASL (qEASL) and the Liver Imaging Reporting and Data System treatment response algorithm. Kaplan–Meier survival curves were used to compare responders and non-responders for each criterion. Univariate and multivariate Cox proportional hazard ratio (HR) analysis were used to identify covariates associated with overall survival. Fleiss kappa test was used to assess interobserver agreement. ResultsAt multivariate analysis, RECIST 1.1 (HR: 0.26; 95% confidence interval [95% CI]: 0.09–0.75; P=0.01), mRECIST (HR: 0.22; 95% CI: 0.08–0.59; P=0.003), EASL (HR: 0.22; 95% CI: 0.07–0.63; P=0.005), and qEASL (HR: 0.30; 95% CI: 0.12–0.80; P=0.02) showed a significant difference in overall survival between responders and nonresponders. RECIST 1.1 had the highest interobserver reproducibility. ConclusionRECIST and mRECIST seem to be the best compromise between reproducibility and ability to predict overall survival in patients with HCC treated with TARE.

Added Value of CT Arterial Subtraction Images in Liver Imaging Reporting and Data System Treatment Response Categorization for Transcatheter Arterial Chemoembolization-Treated Hepatocellular Carcinoma.

The aim of this study was to assess the benefit of adding arterial subtraction images from computed tomography (CT) to the Liver Imaging Reporting and Data System (LI-RADS) v2018 treatment response (LR-TR) categorization in patients treated with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). This retrospective study included 115 patients with 151 HCCs treated by TACE using an emulsion of doxorubicin and iodized oil who underwent multiphasic CT protocol that additionally generated arterial subtraction images based on nonrigid anatomic correction algorithm. Of 151 HCCs, 67 (44.4%) were viable and 84 (55.6%) were nonviable. Two independent readers assessed the per-lesion LR-TR categories in set 1 of multiphasic CT images alone and set 2 including both set 1 and CT arterial subtraction images, besides diagnostic confidence, and the quality of subtraction images. The sensitivity and specificity of LR-TR viable category between the sets were compared using the generalized estimating equation. Interobserver agreements of LR-TR categorization in each set and the quality of subtraction images were assessed by Cohen κ. The quality of subtraction images was mostly good to perfect (98.7%) with good interobserver agreement (κ = 0.71), and none were nondiagnostic. For detecting viable HCC, LR-TR viable category showed sensitivity of 53.7% to 56.7% and specificity of 96.4% to 98.8% in set 1. In comparison, set 2 showed significantly higher sensitivity of 88.1% to 89.6% (P < 0.002) and equivalent specificity of 94% to 95.2% (P > 0.13) for the same category. In sets 1 and 2, 31.3% to 34.3% and 9% to 10.4% of viable HCC were miscategorized as LR-TR nonviable, respectively. LR-TR equivocal category was less assigned in set 2 (1.3%) than in set 1 (6.6%-7.9%). Set 2 showed slightly higher level of confidence for LR-TR categorization compared with set 1 (3.4 ± 0.8 vs 3.8 ± 0.5). Interobserver agreement was excellent in both sets (κ = 0.85 in set 1 and 0.97 in set 2). The LR-TR viable category is highly specific but inadequately sensitive for detecting viable tumor in TACE-treated HCC on conventional multiphasic CT. Adding arterial subtraction images to the conventional CT images significantly increases sensitivity without compromising the specificity and improves the diagnostic confidence of LR-TR viable category.

Diagnostic Performance of LI-RADS Treatment Response Algorithm for Hepatocellular Carcinoma: Adding Ancillary Features to MRI Compared with Enhancement Patterns at CT and MRI.

Background The Liver Imaging Reporting and Data System Treatment Response (LR-TR) algorithm is used to assess the response of hepatocellular carcinoma (HCC) to local-regional therapy (LRT) based on enhancement patterns. The potential value of adding MRI ancillary features (AFs) needs to be investigated. Purpose To evaluate the potential application of MRI AFs in category adjustment to detect pathologic tumor viability in comparison with the LR-TR algorithm in CT and gadoxetic acid-enhanced MRI. Materials and Methods This retrospective study included patients with HCCs treated with LRT followed by surgical resection or liver transplantation between January 2014 and December 2017 who underwent both post-LRT CT and gadoxetic acid-enhanced MRI. For each treated observation, treatment response (TR) categories were assigned based on a consensus reading of three radiologists according to the LR-TR algorithm in CT and MRI and according to the MRI-modified TR algorithm in which MRI AFs were allowed for category adjustment. The diagnostic performances of CT LR-TR viable, MRI LR-TR viable, and MRI-modified TR viable categories were compared intraindividually with the McNemar test, with pathologic tumor viability used as a reference standard. Results A total of 138 patients (119 men; mean age, 58 years ± 9 [standard deviation]) with 138 treated observations (108 pathologically viable) were evaluated. The sensitivity and specificity of CT LR-TR viable and MRI LR-TR viable categories for predicting tumor viability were 73% (79 of 108 lesions; 95% confidence interval [CI]: 64%, 81%) versus 76% (82 of 108 lesions; 95% CI: 67%, 84%) and 90% (27 of 30 lesions; 95% CI: 74%, 98%) versus 83% (25 of 30 lesions; 95% CI: 65%, 94%), respectively, without differences between CT and MRI (P = .65 and P = .63, respectively). MRI-modified TR viable category had higher sensitivity (84% [91 of 108 lesions; 95% CI: 76%, 91%]) than CT or MRI LR-TR viable category (P = .002 and P = .01, respectively), without difference in specificity (80% [24 of 30 lesions]; 95% CI: 61%, 92%) (P = .38 and P > .99, respectively). Conclusion The application of MRI ancillary features to the Liver Imaging Reporting and Data System Treatment Response algorithm resulted in higher sensitivity and no change in specificity compared with CT or MRI enhancement patterns alone in the prediction of pathologic tumor viability in patients with hepatocellular carcinoma. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Do and Mendiratta-Lala in this issue.

Performance of LI-RADS version 2018 CT treatment response algorithm in tumor response evaluation and survival prediction of patients with single hepatocellular carcinoma after radiofrequency ablation.

BackgroundThe Liver Imaging Reporting and Data System treatment response algorithm (LI-RADS TRA) was developed to evaluate the tumor response of patients with hepatocellular carcinoma (HCC) after locoregional treatments. This study aimed to evaluate the performance of LI-RADS computed tomography (CT) TRA version 2018 in tumor response assessment and survival prediction of patients with single HCC after radiofrequency ablation (RFA).MethodsForty patients who underwent RFA for single HCC between 2010 and 2016 were included in this retrospective study. The overall survival (OS) data from all the patients after the first therapy was collected. Two readers independently assessed the pretreatment (within 7 d) and posttreatment (within 90 d after RFA) CT manifestations using the LI-RADS version 2018 CT TRA. Inter-reader agreement was assessed. Another radiologist re-evaluated any divergent results and came to the final conclusion. The performance of LI-RADS version 2018 CT TRA for tumor response assessment and predicting survival of patients with single HCC after RFA was evaluated.ResultsInterobserver agreement was moderate between the 2 readers [κ=0.602, 95% confidence interval (CI): 0.390–0.814] when using LI-RADS version 2018 TRA to evaluate tumor response for patients with single HCC after RFA. Patients classified as LR-TR viable had significantly lower OS than those classified as LR-TR nonviable (P=0.005) and LR-TR equivocal (P=0.036). However, the OS between LR-TR nonviable and LR-TR equivocal did not differ significantly (P=0.901).ConclusionsLI-RADS version 2018 CT TRA can be applied to predict viable or nonviable HCC after RFA. Patients with LR-TR viable had significantly lower OS than those with LR-TR nonviable and LR-TR equivocal. More research is needed to validate the performance of LI-RADS version 2018 TRA in HCC tumor response evaluation, to better grasp the use of the tie-breaking rule, and to improve the accuracy of prediction for tumor viability.

MRI Assessment of Hepatocellular Carcinoma after Local-Regional Therapy: A Comprehensive Review.

Nearly 80% of cirrhotic patients diagnosed with hepatocellular carcinoma (HCC) are not eligible for surgical resection and instead undergo local-regional treatment. After therapy for HCC, patients undergo imaging surveillance to assess treatment efficacy and identify potential sites of progressive tumor elsewhere within the liver. Accurate interpretation of posttreatment imaging is essential for guiding further management decisions, and radiologists must understand expected treatment-specific imaging findings for each of the local-regional therapies. Of interest, expected imaging findings seen after radiation-based therapies (transarterial radioembolization and stereotactic body radiation therapy) are different than those seen after thermal ablation and transarterial chemoembolization. Given differences in expected posttreatment imaging findings, the current radiologic treatment response assessment algorithms used for HCC (modified Response Evaluation Criteria in Solid Tumors classification, European Association for the Study of Liver Diseases criteria, and Liver Imaging and Reporting Data System Treatment Response Algorithm) must be applied cautiously for radiation-based therapies in which persistent arterial phase hyperenhancement in the early posttreatment period is common and expected. This article will review the concept of tumor response assessment for HCC, the forms of local-regional therapy for HCC, and the expected posttreatment findings for each form of therapy. Keywords: Abdomen/GI, Liver, MR-Imaging, Treatment Effects, Tumor Response © RSNA, 2020.

Validation of the Liver Imaging Reporting and Data System Treatment Response Criteria After Thermal Ablation for Hepatocellular Carcinoma

Validation of the Liver Imaging Reporting and Data System Treatment Response Criteria After Thermal Ablation for Hepatocellular Carcinoma

Validation of the Liver Imaging Reporting and Data System Treatment Response Criteria After Thermal Ablation for Hepatocellular Carcinoma.

Single hepatocellular carcinoma (HCC) tumors can be successfully eradicated with thermal ablation (TA). We assessed the validity of the Liver Imaging Reporting and Data System Treatment Response (LR-TR) criteria with a retrospective analysis of a single-center database of patients with small HCC tumors (<3cm in diameter) who underwent both laparoscopic TA and liver transplantation (LT) from 2004 to 2018. Postablation MRIs were assigned LR-TR categories (nonviable, equivocal, and viable) for ablated lesions and Liver Imaging Reporting and Data System (LI-RADS) categories (probable or definite HCC) for untreated lesions. Interpretations were compared with the histopathology of the post-LT explanted liver. There were 45 patients with 81 tumors (59 ablated and 22 untreated; mean size, 2.2cm), and 23 (39%) of the ablated tumors had viable HCC on histopathology. The sensitivity/specificity of LR-TR categories (nonviable/equivocal versus viable) of ablated tumors was 30%/99%, with a positive predictive value (PPV)/negative predictive value (NPV) of 93%/69%. The sensitivity varied with residual tumor size. The sensitivity/specificity of LI-RADS 4 and 5 diagnostic criteria at detecting new HCC was 65%/94%, respectively, with a PPV/NPV of 85%/84%. The interrater reliability (IRR) was high for LR-TR categories (90% agreement, Cohen's ĸ=0.75) and for LI-RADS LR-4 and LR-5 diagnostic categories (91% agreement, Cohen's ĸ=0.80). In patients with HCC <3cm in diameter, LR-TR criteria after TA had high IRR but low sensitivity, suggesting that the LR-TR categories are precise but inaccurate. The low sensitivity may be secondary to TA's disruption in the local blood flow of the tissue, which could affect the arterial enhancement phase on MRI. Additional investigation and new technologies may be necessary to improve imaging after ablation.

The LI-RADS Version 2018 MRI Treatment Response Algorithm: Evaluation of Ablated Hepatocellular Carcinoma.

Background The Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA) is used to assess presumed hepatocellular carcinoma (HCC) after local-regional therapy, but its performance has not been extensively assessed. Purpose To assess the performance of LI-RADS version 2018 TRA in the evaluation of HCC after ablation. Materials and Methods In this retrospective study, patients who underwent ablation therapy for presumed HCC followed by liver transplantation between January 2011 and December 2015 at a single tertiary care center were identified. Lesions were categorized as completely (100%) or incompletely (≤99%) necrotic based on transplant histology. Three radiologists assessed pre- and posttreatment MRI findings using LI-RADS version 2018 and the TRA, respectively. Interreader agreement was assessed by using the Fleiss κ test. Performance characteristics for predicting necrosis category based on LI-RADS treatment response (LR-TR) category (viable or nonviable) were calculated by using generalized mixed-effects models to account for clustering by subject. Results A total of 36 patients (mean age, 58 years ± 5 [standard deviation]; 32 men) with 53 lesions was included. Interreader agreement for pretreatment LI-RADS category was 0.40 (95% confidence interval [CI]: 0.15, 0.67; P < .01) and was lower than the interreader agreement for TRA category (κ = 0.71; 95% CI: 0.59, 0.84; P < .01). After accounting for clustering by subject, sensitivity of tumor necrosis across readers ranged from 40% to 77%, and specificity ranged from 85% to 97% when LR-TR equivocal assessments were treated as nonviable. When LR-TR equivocal assessments were treated as viable, sensitivity of tumor necrosis across readers ranged from 81% to 87%, and specificity ranged from 81% to 85% across readers. Six (11%) of 53 treated lesions were LR-TR equivocal by consensus, with most (five of six) incompletely necrotic at histopathology. Conclusion The Liver Imaging Reporting and Data System treatment response algorithm can be used to predict viable or nonviable hepatocellular carcinoma after ablation. Most ablated lesions rated as treatment response equivocal were incompletely necrotic at histopathology. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Do and Mendiratta-Lala in this issue.