Short-term outcome of adrenal radiofrequency ablation of adrenal cysts: a single-center experience.

Percutaneous thermal ablation is a minimally invasive treatment for liver, kidney, lung, bone, and thyroid tumors. This treatment also has been used to treat adrenal tumors in patients, but there is no evidence for the efficacy of thermal ablation of adrenal cysts. The present study was performed to analyze the experience of a single center with percutaneous radiofrequency ablation (RFA) of adrenal cysts and to evaluate its efficacy. The present study enrolled all patients who underwent percutaneous RFA for unilateral adrenal cysts from 2019 to 2021. All patients underwent USG-guided percutaneous aspiration of cystic fluid, followed by RFA. A total nine patients with adrenal cysts were included in this study. All of them underwent technically successful percutaneous RFA, with no immediate complication. Follow-up CT 3 months after RFA showed that six of the nine adrenal cysts showed good responses, with reductions in cyst volume ranging from 86.4 to 97.9%. One patient had poor response in the cyst size (volume reduction rate 11.2%). She underwent secondary RFA with resulting that the cyst volume reduced by 91.1%. After a median follow-up period of 17.2 months, eight patients showed no evidence of regrowth. The patient, who showed evidence of regrowth, declined any other treatment and has been under regular surveillance. None of the nine patients developed adrenal insufficiency during the follow-up period. In conclusion, percutaneous RFA is a safe and effective minimally invasive treatment for adrenal cysts, suggesting that percutaneous RFA may be a good alternative option in selected patients.

New strategy for Liver Imaging Reporting and Data System category M to improve diagnostic performance of MRI for hepatocellular carcinoma ≤ 3.0 cm.

PURPOSE: We aimed to determine a new strategy for Liver Imaging Reporting and Data System category M (LR-M) criteria to improve the diagnosis of HCC ≤ 3.0 cm on magnetic resonance imaging (MRI). METHODS: A total of 463 pathologically confirmed hepatic observations ≤ 3.0 cm (375 HCCs, 32 other malignancies, 56 benignities) in 384 patients at risk of HCC who underwent gadoxetate-enhanced MRI were retrospectively analyzed. Two radiologists evaluated the presence of major, ancillary, and LR-M features according to LI-RADS v2018. Of the ten LR-M features, those significantly associated with non-HCC malignancy were identified using multivariable logistic regression analysis, and new LR-M criteria for improving the diagnosis of HCC were investigated. Generalized estimating equations were used to compare sensitivity and specificity of LR-5 for diagnosing HCC using the new LR-M criteria with values calculated using the original LR-M criteria. p < 0.05 was considered to indicate a significant difference. RESULTS: Of ten LR-M features, rim arterial-phase hyperenhancement, delayed central enhancement, targetoid restriction, and targetoid transitional-phase/hepatobiliary-phase appearance were independently significantly associated with non-HCC malignancy (adjusted odds ratio ≥ 6.2; p ≤ 0.02). Using the new LR-M criteria (two or more of these significant features), the sensitivity of LR-5 for diagnosing HCC was higher than that with the original LR-M criteria (69% [95% confidence interval 64-73%] vs. 65% [61-70%], p = 0.002), whereas the specificity was similar (90% [82-95%] vs. 92% [83-96%], p = 0.28). CONCLUSION: The new LR-M criteria (two or more significant features) can improve the sensitivity of LR-5 for diagnosing HCC ≤ 3.0 cm, without compromising specificity.

Thermal ablation in the treatment of intrahepatic cholangiocarcinoma: a systematic review and meta-analysis.

OBJECTIVE: To summarize the efficacy and safety of thermal ablation for the treatment of intrahepatic cholangiocarcinoma (ICC). METHODS: MEDLINE, EMBASE, Cochran Library, and Web of Science databases were searched for studies reporting outcomes in patients with ICC treated with thermal ablation. Meta-analyses of cumulative overall survival (OS) and recurrence-free survival (RFS), Kaplan-Meier survival rates according to time to local tumor progression (TTLTP), technical efficacy, and incidence of complications were analyzed. Pooled hazard ratios of common variables were calculated to explore factors associated with OS. RESULTS: Twenty observational studies comprising 917 patients were reviewed (primary ICC [n = 502]; post-surgical recurrent ICC [n = 355]; information not available [n = 60]). The pooled proportion of technical efficacy was 91.9% (95% CI, 87.3-94.9%). The pooled 1-, 3-, and 5-year OS rates were 82.4% (95% CI, 75.1-88.9%), 42.1% (95% CI, 36.0-48.4%), and 28.5% (95% CI, 21.2-36.2%). Primary tumors showed higher 3-year OS rates than recurrent ones, with borderline significance (p = 0.072). The pooled 1- and 3-year RFS rates were 40.0% (95% CI, 33.6-46.4%) and 19.2% (95% CI, 8.4-32.7%). The pooled 1-, 3-, and 5-year TTLTP rates were 79.3% (95% CI, 65.1-90.9%), 59.5% (95% CI, 49.1-69.4%), and 58.2% (95% CI, 44.9-70.9%). The pooled incidence of major complications was 5.7% (95% CI, 4.1-7.8%). Tumor size (> 3 cm), multiple tumors, and age (> 65 years) were factors associated with shorter OS. CONCLUSION: Thermal ablation is a successful alternative with a good safety profile, especially for a single ICC smaller than 3 cm. KEY POINTS: • The pooled 1-, 3-, and 5-year OS rates following thermal ablation for the treatment of intrahepatic cholangiocarcinoma were 82.4%, 42.1%, and 28.5%. • The pooled incidence of major complications was 5.7%. • A tumor size > 3 cm (HR: 2.12, p = 0.006), multiple tumors (HR: 1.67, p = 0.004), and age > 65 years (HR: 1.67, p = 0.006) were factors associated with shorter OS.

Outcome of No-Touch Radiofrequency Ablation for Small Hepatocellular Carcinoma: A Multicenter Clinical Trial.

Background Recently introduced no-touch radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) has the potential to improve local tumor control. Purpose To evaluate midterm clinical outcomes of monopolar no-touch RFA in single HCCs 2.5 cm or smaller. Materials and Methods In this multicenter clinical trial (ClinicalTrials.gov: NCT03375281), participants were evaluated for eligibility from November 2017 to January 2019. Patients with single HCCs 2.5 cm or smaller planning to be treated with no-touch RFA were enrolled. The rate of successful no-touch RFA, defined as performing RFA without violation of the tumor itself, was recorded. Multivariable logistic regression analysis was used to determine associated factors for failure of no-touch RFA. Development of major complication after no-touch RFA was also recorded. Cumulative incidence of local tumor progression (LTP) and recurrence-free survival were estimated by using the Kaplan-Meier method. Results A total of 140 participants (mean age, 62 years ± 9 [standard deviation]; 106 men) were evaluated. No-touch RFA was successfully performed in 128 participants (128 of 140; 91.4%), and conversion to tumor puncture RFA was undertaken in 12 participants because of the lack of a safe access route. By using either no-touch RFA or conversion to tumor puncture RFA, all participants achieved technical success of RFA, which was defined as complete coverage of target tumor by ablation zone. Insufficient peritumoral parenchyma (<5 mm width around more than half portion of tumor; odds ratio, 74; 95% CI: 18, 309; P < .001) was the only significant predictive factor for failure of the no-touch technique. Among the 140 participants, LTP developed in two participants, and the estimated 1- and 2-year cumulative incidence of LTP was 0.7% and 1.6%, respectively. The estimated 1- and 2-year recurrence-free survival was 82.8% and 74.1%, respectively. Conclusion No-touch radiofrequency ablation was an effective and safe treatment method for small hepatocellular carcinomas (≤2.5 cm), with 1.6% of cumulative incidence of local tumor progression at 2 years. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Soulen and García-Mónaco in this issue.

Percutaneous Radiofrequency Ablation for Recurrent Intrahepatic Cholangiocarcinoma After Curative Resection: Multivariable Analysis of Factors Predicting Survival Outcomes.

OBJECTIVE. The purpose of this study was to evaluate the factors associated with local tumor progression (LTP) and overall survival (OS) in patients who have undergone percutaneous radiofrequency ablation (RFA) for recurrent intrahepatic cholangiocarcinoma (iCCA) after curative resection. MATERIALS AND METHODS. Data from 40 patients (mean age, 56.3 years) with 64 recurrent iCCAs (median diameter, 1.5 cm) who underwent percutaneous RFA between 1999 and 2019 were retrospectively analyzed. Patients were included if they had three or fewer metastases, a maximum tumor diameter of 5 cm or less, and disease confined to the liver. RESULTS. Technical success was achieved in all patients, with no procedure-related mortality. During follow-up, local progression of treated lesions was observed in 31.3% of tumors. The median OS and 5-year survival rate from initial RFA were 26.6 months and 18.3%, respectively. Multivariable analysis showed that a larger tumor diameter (> 2 cm, p = .004) was significantly associated with reduced LTP-free survival and that both a larger tumor diameter and less than 1 year from surgery to recurrence (p = .005 and .006, respectively) were statistically significant predictors of reduced OS after RFA. CONCLUSION. Percutaneous RFA may offer a well-tolerated and successful approach to local tumor control in patients with recurrent iCCA after curative surgery. Patients with a small-diameter tumor (≤ 2 cm) and late hepatic recurrence (≥ 1 year after curative resection) benefited most from RFA treatment.

Combined computed tomography and magnetic resonance imaging improves diagnosis of hepatocellular carcinoma ≤ 3.0 cm.

BACKGROUND/PURPOSE: Imaging diagnosis of hepatocellular carcinoma (HCC) is important, but the diagnostic performance of combined computed tomography (CT) and magnetic resonance imaging (MRI) using the Liver Imaging Reporting and Data System (LI-RADS) v2018 is not fully understood. We evaluated the clinical usefulness of combined CT and MRI for diagnosing HCC ≤ 3.0 cm using LI-RADS. METHODS: In 222 patients at risk of HCC who underwent both contrast-enhanced dynamic CT and gadoxetate disodium-enhanced MRI in 2017, 291 hepatic nodules ≤ 3.0 cm were retrospectively analyzed. Two radiologists performed image analysis and assigned a LI-RADS category to each nodule. The diagnostic performance for HCC was evaluated for CT, ordinary-MRI (washout confined to portal venous-phase), and modified-MRI (washout extended to hepatobiliary phase), and sensitivity and specificity were calculated for each modality. Generalized estimating equations were used to compare the diagnostic performance for HCC between combined CT and ordinary-MRI, combined CT and modified-MRI, and CT or MRI alone. p < 0.0062 (0.05/8) was considered statistically significant following Bonferroni correction for multiple comparisons. RESULTS: In 291 nodules, the sensitivity and specificity of CT, ordinary-MRI, and modified-MRI were 70.2% and 92.8%, 72.6% and 96.4%, and 84.6% and 88.0%, respectively. Compared with CT or MRI alone, both combined CT and ordinary-MRI (sensitivity, 83.7%; specificity, 95.2%) and combined CT and modified-MRI (sensitivity, 88.9%; specificity, 89.2%) showed significantly higher sensitivity (p ≤ 0.006), without a significant decrease in specificity (p ≥ 0.314). CONCLUSIONS: Compared with CT or MRI alone, combined CT and MRI can increase sensitivity for diagnosing HCC ≤ 3.0 cm, without a significant decrease in specificity.

Value of discrepancy of the central scar-like structure between dynamic CT and gadoxetate disodium-enhanced MRI in differentiation of focal nodular hyperplasia and hepatocellular adenoma.

PURPOSE: To identify the value of discrepancies in the central scar (CS)-like structure between dynamic CT and gadoxetate disodium-enhanced MRI for differentiating FNH from HCA. METHODS: This retrospective study included 113 patients with pathologically-diagnosed FNH (n = 80) or HCA (n = 37). CS-like structures were evaluated on arterial phase (AP) CT and hepatobiliary phase (HBP) MRI. Presence of the CS-like structure, its discrepancy in visibility or size between AP CT and HBP MRI and between AP and HBP MRI, and features of non-scarred tumor portion were evaluated by two radiologists. Inter-observer agreement was evaluated by intraclass correlation coefficients (ICCs) and weighted kappa. Univariable and multivariable logistic regression and ROC analysis were performed to explore features differentiating FNH from HCA. RESULTS: Inter-observer agreement was moderate-to-excellent (ICCs≥0.74, kappa≥0.65). On univariable analysis, presence of CS-like structures (P < 0.001), discrepancy of the CS-like structures between AP CT and HBP MRI (73.8 % in FNH; 16.2 % in HCA, P < 0.001) and between AP and HBP MRI (70.0 % in FNH; 16.2 % in HCA, P < 0.001), and the features of non-scarred tumor portion (P ≤ 0.011) were significantly different between FNH and HCA. On multivariable analysis, the discrepancy of CS-like structures between AP CT and HBP MRI, and the absence of low SI of the non-scarred tumor portion on HBP MRI, were suggestive of FNH (P = 0.036 and P < 0.001, respectively; area under the ROC curve, 0.96 [95 % CI, 0.93-0.99]). CONCLUSION: Evaluation of discrepancy in the visibility or size of CS-like structures between dynamic CT and gadoxetate disodium-enhanced MRI may facilitate the differentiation of FNH from HCA.

US LI-RADS visualization score: diagnostic outcome of ultrasound-guided focal hepatic lesion biopsy in patients at risk for hepatocellular carcinoma.

PURPOSE: This study investigated the diagnostic outcome of ultrasound (US)-guided focal hepatic lesion biopsy in patients at risk for hepatocellular carcinoma (HCC) and evaluated the US visualization score as a risk factor for non-diagnostic results. METHODS: We retrospectively evaluated 208 focal hepatic lesions in 208 patients who underwent US-guided biopsy in 2016. Using the US Liver Imaging Reporting and Data System version 2017, each exam was assigned a US visualization score (A, B, or C). Final diagnoses were made using pathology reports, and biopsy results were categorized as diagnostic or non-diagnostic. Univariable and multivariable analyses were performed to determine risk factors for non-diagnostic results, including US visualization score and other clinical covariates. RESULTS: Of the 208 lesions, 85.1% were diagnostic and 14.9% were non-diagnostic. The rates of non-diagnostic results were 8.9%, 25.5%, and 57.1% for scores of A, B, and C, respectively. In the univariable analysis, scores of B or C were associated with a significantly higher rate of nondiagnostic results than scores of A (58.1% vs. 24.9%, P<0.001). In the multivariable analysis, US visualization score of B or C (adjusted odds ratio [aOR], 2.7; P=0.027), high-risk needle pathway usage (aOR, 5.7; P=0.001), and lesion size ≤2.0 cm (aOR, 2.7; P=0.024) were independent risk factors for non-diagnostic results. CONCLUSION: US-guided biopsy had a high diagnostic yield for focal hepatic lesions in patients at risk for HCC. US visualization score of B or C, lesion size ≤2.0 cm, and high-risk needle pathway usage were independent risk factors for non-diagnostic results.

A Single-Center Retrospective Analysis of Periprocedural Variables Affecting Local Tumor Progression after Radiofrequency Ablation of Colorectal Cancer Liver Metastases.

Background Local tumor progression (LTP) is associated with poorer survival in patients undergoing radiofrequency ablation (RFA) for colorectal liver metastasis (CLM). An algorithmic strategy to predict LTP may help in selection of patients who would benefit most from RFA for CLM. Purpose To estimate local tumor progression-free survival (LTPFS) following RFA of CLM and develop an algorithmic strategy based on clinical variables. Materials and Methods In this retrospective study, between March 2000 and December 2014, patients who underwent percutaneous RFA for CLM were randomly split into development (60%) and internal validation (40%) data sets. Kaplan-Meier method was used to estimate LTPFS and overall survival (OS) rates. Independent factors affecting LTPFS in the development data set were investigated by using multivariable Cox proportional hazard regression analysis. Risk scores were assigned to the risk factors and applied to the validation data set. Results A total of 365 patients (mean age, 60 years ± 11 [standard deviation]; 259 men) with 512 CLMs were evaluated. LTPFS and OS rates were 85% and 92% at 1 year, 73% and 41% at 5 years, 72% and 30% at 10 years, and 72% and 28% at 15 years, respectively. Independent risk factors for LTP included tumor size of 2 cm or greater (hazard ratio [HR], 3.8; 95% CI: 2.3, 6.2; P < .001), subcapsular tumor location (HR, 1.9; 95% CI: 1.1, 3.1; P = .02), and minimal ablative margin of 5 mm or less (HR, 11.7; 95% CI: 4.7, 29.2; P < .001). A prediction model that used the risk factors had areas under the curve of 0.89, 0.92, and 0.90 at 1, 5, and 10 years, respectively, and it showed significantly better areas under the curve when compared with the model using the minimal ablative margin of 5 mm or less alone. Conclusion Radiofrequency ablation provided long-term control of colorectal liver metastases. Although minimal ablative margin of 5 mm or less was the most dominant factor, the multifactorial approach including tumor size and subcapsular location better predicted local tumor progression-free survival. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Soulen and Sofocleous in this issue.

Tract ablation after radiofrequency ablation to prevent viable tumor cell adhesion to the needle electrode.

PURPOSE: To evaluate whether the additive needle tract ablation (TA) can reduce adherent cells on the needle tract after radiofrequency ablation (RFA) in a preclinical HCC mouse model. METHODS: Hep3B-Luc cells were engrafted in the Balb/c-nude mice. Nineteen mice were randomly assigned into three groups: the needle only group (needle placement only without performing RFA), the RFA only group (needle placement with active RFA treatment), and the RFA-TA group (needle placement with active RFA treatment and additive tract ablation). The 17-gauge needle with a 10-mm active tip was used. After RFA and TA, the viability of adherent tumor cells on the RFA needle was evaluated with bioluminescence imaging (BLI) and live-cell counting. RESULTS: We observed that RFA-TA group had the lowest BLI values compared with other groups (needle only group, 11.2 ± 6.4 million; RFA only group, 13.6 ± 9.1 million; RFA-TA group, 1.11 ± 0.8 million, p = 0.001). Live cell counting with acridine orange/propidium iodide staining also confirmed that the counted viable cell numbers in RFA-TA group were lowest compared to the other groups (needle only group, 14.8 ± 4.5; RFA only group, 643.8 ± 131.9; RFA-TA group, 1.5 ± 0.9, p < 0.001). CONCLUSIONS: The additive tract ablation can significantly reduce the number of viable tumor cells adherent to the RFA needle, which can prevent needle tract seeding after RFA procedure.

Accuracy of contrast-enhanced ultrasound liver imaging reporting and data system: a systematic review and meta-analysis.

BACKGROUND AND AIM: After the introduction of the contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS), several studies have reported on its performance, but the reported data vary considerably. Therefore, we performed a systematic review and meta-analysis to determine the diagnostic performance of CEUS LI-RADS in patients at risk for hepatocellular carcinoma (HCC) and investigate the causes of study heterogeneity. METHODS: Original studies published until May 30, 2020, investigating the diagnostic performance of CEUS LI-RADS were identified in the MEDLINE, EMBASE, and Cochrane library databases. Study quality was assessed using the QUADAS-2 tool. Meta-analytic summary sensitivity and specificity for the diagnosis of HCC were calculated using a bivariate random-effects model. Meta-regression analysis was performed to explore the causes of study heterogeneity. RESULTS: Of the 105 articles screened, eight studies were finally analyzed (5428 hepatic observations). The summary sensitivity and specificity of CEUS LI-RADS category 5 (LR-5) for diagnosing HCC were 73% [95% confidence interval (CI) 65-79%; I2 = 93%] and 95% (95% CI 91-97%; I2 = 89%), respectively. Substantial study heterogeneity was noted in both sensitivity and specificity. Study heterogeneity was significantly associated with the proportion of cases of HCC and the type of reference standard (p ≤ 0.05). CONCLUSION: CEUS LI-RADS had high pooled specificity for diagnosing HCC but suboptimal pooled sensitivity. Substantial study heterogeneity was found, which was significantly associated with the proportion of cases of HCC and the type of reference standard.

Comparison of the diagnostic performance of imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced MRI.

BACKGROUND AND PURPOSE: Imaging-based diagnostic systems play important roles in hepatocellular carcinoma (HCC). We aimed to compare the diagnostic performance of recently updated imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced magnetic resonance imaging (MRI). METHODS: 493 nodules (399 HCCs, 24 other malignancies, 70 benign) 1.0-3.0 cm from 400 patients, including 322 male (mean age 59.3 ± 9.4 years) and 78 female (mean age 61.2 ± 9.0 years), at risk for HCC who underwent gadoxetate disodium-enhanced MRI between July 2015 and December 2016 were retrospectively evaluated. Final diagnosis was determined histopathologically or clinically. The sensitivity and specificity in diagnosing HCC of the latest versions of four imaging criteria [Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), Korean Liver Cancer Association-National Cancer Center (KLCA-NCC)] were compared using generalized estimating equations. RESULTS: In 331 only pathologically diagnosed nodules, the sensitivities of both the APASL (86.8%) and KLCA-NCC criteria (85.4%) were significantly higher than the sensitivities of the EASL (71.8%) and LR-5 (71.1%) criteria (p < 0.001 for each pairwise comparison). However, the specificity of LR-5 was significantly higher than that of APASL (92.2% vs. 70.6%, respectively; p = 0.011) but did not differ significantly from the specificities of EASL (84.3%; p = 0.634) and KLCA-NCC (78.4%; p = 0.107). CONCLUSION: Of the four international imaging criteria, LI-RADS and EASL showed high specificity but suboptimal sensitivity for diagnosing HCCs ≤ 3 cm. However, APASL and KLCA-NCC had a higher sensitivity but a lower specificity than LI-RADS and EASL.

Liver imaging reporting and data system category M: A systematic review and meta-analysis.

BACKGROUND AND AIMS: The Liver Imaging Reporting and Data System (LI-RADS) category M (LR-M) was introduced to preserve the high specificity of LI-RADS algorithm for diagnosing hepatocellular carcinoma (HCC). We aimed to systematically determine the probability of the LR-M for HCC and non-HCC malignancy, and to determine the sources of heterogeneity between reported results. METHODS: Original studies reporting the probability of LR-M for HCC and non-HCC malignancy on magnetic resonance imaging (MRI) were identified in MEDLINE and EMBASE. The meta-analytic pooled percentages of HCC and non-HCC in LR-M were calculated. Meta-regression analysis was performed to explore study heterogeneity. The meta-analytic frequency of each LR-M imaging feature was determined. RESULTS: We found 10 studies reporting the diagnostic performance of LR-M (1819 lesions in 1631 patients), and six reporting the frequency of LR-M imaging features. The pooled percentages of HCC and non-HCC malignancy for LR-M were 28.2% (95% confidence interval [CI], 23.8%-33.1%; I2  = 83%) and 69.6% (95% CI, 64.6%-74.1%; I2  = 83%) respectively. The study type and MRI scanner field strength were significantly associated with study heterogeneity (P ≤ .04). Of the seven imaging features, rim arterial phase hyperenhancement showed the highest frequency in both non-HCC (48.9%; 95% CI, 43.0%-54.8%) and HCC groups (9.8%; 95% CI, 6.9%-13.6%). CONCLUSIONS: The LR-M category most commonly included non-HCC malignancy but also included 28.2% of HCC. Substantial study heterogeneity was noted, and it was significantly associated with study type and MRI scanner field strength. In addition, the frequency of LR-M imaging features was variable.

Percutaneous Radiofrequency Ablation for Metachronous Hepatic Metastases after Curative Resection of Pancreatic Adenocarcinoma.

OBJECTIVE: To retrospectively evaluate the safety and efficacy of percutaneous radiofrequency ablation (RFA) in patients with metachronous hepatic metastases arising from pancreatic adenocarcinoma who had previously received curative surgery. MATERIALS AND METHODS: Between 2002 and 2017, percutaneous RFA was performed on 94 metachronous hepatic metastases (median diameter, 1.5 cm) arising from pancreatic cancer in 60 patients (mean age, 60.5 years). Patients were included if they had fewer than five metastases, a maximum tumor diameter of ≤ 5 cm, and disease confined to the liver or stable extrahepatic disease. For comparisons during the same period, we included 66 patients who received chemotherapy only and met the same eligibility criteria described. RESULTS: Technical success was achieved in all hepatic metastasis without any procedure-related mortality. During follow-up, local tumor progression of treated lesions was observed in 38.3% of the tumors. Overall median survival and 3-year survival rates were 12 months and 0%, respectively from initial RFA, and 14.7 months and 2.1%, respectively from the first diagnosis of liver metastasis. Multivariate analysis showed that a large tumor diameter of > 1.5 cm, a late TNM stage (≥ IIB) before curative surgery, a time from surgery to recurrence of < 1 year, and the presence of extrahepatic metastasis, were all prognostic of reduced overall survival after RFA. Median overall (12 months vs. 9.1 months, p = 0.094) and progression-free survival (5 months vs. 3.3 months, p = 0.068) were higher in the RFA group than in the chemotherapy group with borderline statistical difference. CONCLUSION: RFA is safe and may offer successful local tumor control in patients with metachronous hepatic metastases arising from pancreatic adenocarcinoma. Patients with a small diameter tumor, early TNM stage before curative surgery, late hepatic recurrence, and liver-only metastasis benefit most from RFA treatment. RFA provided better survival outcomes than chemotherapy for this specific group with borderline statistical difference.

Ancillary features in the Liver Imaging Reporting and Data System: how to improve diagnosis of hepatocellular carcinoma ≤ 3 cm on magnetic resonance imaging.

OBJECTIVES: To determine the strength of association with hepatocellular carcinoma (HCC) of each ancillary feature (AF) in LI-RADS version 2018, and to develop an appropriate strategy for applying AFs to improve the diagnosis of HCC ≤ 3 cm on gadoxetate-enhanced MRI. METHODS: A total of 385 nodules (283 HCCs, 18 non-HCC malignancies, 84 benign nodules) of ≤ 3 cm in 266 patients at risk for HCC who underwent gadoxetate-enhanced MRI in 2016 were retrospectively evaluated. Two radiologists independently evaluated the presence/absence of AFs, and assigned a LI-RADS category to each nodule. Diagnostic odds ratio (DOR) of each AF was assessed. To improve the diagnostic performance for HCC, various criteria were developed based on the number of AFs favoring malignancy in general or HCC in particular. Generalized estimating equation models were used to compare the diagnostic performance of each criterion with that of the major features (MFs) only. RESULT: All AFs favoring HCC in particular and malignancy in general were more common in the HCC group than in the non-HCC group. Of these AFs, hepatobiliary-phase hypointensity had the strongest association with HCC (DOR, 21.82; 95% confidence interval, 5.59-85.20). When we applied AFs in addition to MFs, the new criterion (with a number of AFs ≥ 4) had significantly higher sensitivity (80.6% vs. 70.0%; p < 0.001) than MFs only, without significant lower specificity (85.3% vs. 90.2%; p = 0.060). CONCLUSIONS: The AFs varied in the strengths of association with HCC. More strict application of AFs (AFs ≥ 4) in LR-3 may improve the diagnostic performance for probable HCC ≤ 3 cm. KEY POINTS: • The ancillary features (AFs) in the Liver Imaging Reporting and Data System version 2018 showed variable frequencies of occurrence and strengths of association with hepatocellular carcinoma (HCC). • Of the various AFs, hepatobiliary-phase hypointensity had the highest frequency and strongest association with HCC on gadoxetate disodium-enhanced MRI. • When applying AFs in addition to major features, a criterion of four or more AFs significantly increased the sensitivity for diagnosing HCC, without a significantly decreased specificity, especially in LR-3 observations.

Surgical resection versus radiofrequency ablation very early-stage HCC (≤2 cm Single HCC): A propensity score analysis.

BACKGROUND & AIM: Hepatocellular carcinoma (HCC) is increasingly being detected at a very early-stage due to the wide implementation of the surveillance of at-risk patient populations combined with improved imaging technologies. Whether patients with HCC at a very early stage can be offered local ablation as a first-line treatment option still remains controversial. We retrospectively compared the effectiveness of surgical resection (SR) and radiofrequency ablation (RFA) for Barcelona Clinic Liver Cancer (BCLC) very early-stage HCC in patients with long-term follow-up. METHODS: Propensity score analysis using inverse probability weighting (IPW) from a large-volume liver centre. We included adult patients who between 2000 and 2013 received a diagnosis of very early-stage HCC (BCLC stage 0; a single tumour ≤2 cm, Child-Pugh A class, eastern cooperative oncology group [ECOG] 0) and who were treated with SR or RFA as the first-line treatment. RESULTS: We identified 1208 patients, 631 in the SR group and 577 in the RFA group. The median follow-up time was 86.2 months. After propensity score analysis using IPW, the 15-year overall survival rates were 60.4% and 51.6% in the SR and RFA group respectively. RFA group showed poorer overall survival than SR group (adjusted hazard ratio, 1.29; P = .0378). The 15-year recurrence-free survival rates were 37% and 23.6% in the SR and RFA group respectively (P < .001). CONCLUSION: For patients with very early-stage HCC, the SR group was associated with better overall and recurrence-free patient survival compared to the RFA group. Therefore, SR should be considered as the first-line treatment for these patients.

Chemoembolization Combined with Radiofrequency Ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis.

PURPOSE: To compare survival outcomes of patients with single medium-sized hepatocellular carcinomas (HCCs) who underwent treatment with transarterial chemoembolization, radiofrequency (RF) ablation, or a combination of the 2 therapies. MATERIALS AND METHODS: Between 2000 and 2016, 538 patients underwent combined chemoembolization and RF ablation (n = 109), chemoembolization alone (n = 314), or RF ablation alone (n = 115) as first-line treatment for a single medium-sized (3.1-5.0 cm) HCC. Baseline demographic data (age, sex, etiology, Eastern Cooperative Oncology Group performance status, presence of liver cirrhosis, and serum bilirubin, albumin, and α-fetoprotein levels) were similar among groups except for Child-Pugh class, albumin level, and tumor size. Propensity-score analysis with inverse probability weighting (IPW) was used to reduce any bias in treatment selection and other potential confounding factors. RESULTS: Median follow-up time was 46.2 months. Before IPW, overall survival (OS) durations were significantly different among the 3 groups (median, 85 months for combined therapy, 56.5 months for chemoembolization alone, and 52.1 months for RF ablation alone; P = .01). The 10-year OS rates were 40.1%, 25.5%, and 19.5% for the combined, chemoembolization-only, and RF ablation-only groups, respectively. After IPW, OS remained superior in the combined chemoembolization/RF ablation group compared with the monotherapy groups (10-y OS, 41.8% with combined therapy, 28.4% with chemoembolization alone, and 11.9% with RF ablation alone; P = .022). CONCLUSIONS: Chemoembolization plus RF ablation may provide better survival outcomes than chemoembolization or RF ablation monotherapy, and can be considered a viable alternative treatment for unresectable single medium-sized HCCs.

Arterial subtraction images of gadoxetate-enhanced MRI improve diagnosis of early-stage hepatocellular carcinoma.

BACKGROUND & AIMS: Although gadoxetate disodium-enhanced magnetic resonance imaging (MRI) shows higher sensitivity for diagnosing hepatocellular carcinoma (HCC), its arterial-phase images may be unsatisfactory because of weak arterial enhancement. We investigated the clinical effectiveness of arterial subtraction images from gadoxetate disodium-enhanced MRI for diagnosing early-stage HCC using the Liver Imaging Reporting and Data System (LI-RADS) v2018. METHODS: In 258 patients at risk of HCC who underwent gadoxetate disodium-enhanced MRI in 2016, a total of 372 hepatic nodules (273 HCCs, 18 other malignancies, and 81 benign nodules) of 3.0 cm or smaller were retrospectively analyzed. Final diagnosis was assessed histopathologically or clinically (marginal recurrence after treatment or change in lesion size on follow-up imaging). The detection rate for arterial hyperenhancement was compared between ordinary arterial-phase and arterial subtraction images, and the benefit of arterial subtraction images in diagnosing HCC using LI-RADS was assessed. RESULTS: Arterial subtraction images had a significantly higher detection rate for arterial hyperenhancement than ordinary arterial-phase images, both for all hepatic nodules (72.3% vs. 62.4%, p <0.001) and HCCs (91.9% vs. 80.6%, p <0.001). Compared with ordinary arterial-phase images, arterial subtraction images significantly increased the sensitivity of LI-RADS category 5 for diagnosis of HCC (64.1% [173/270] vs. 55.9% [151/270], p <0.001), without significantly decreasing specificity (92.9% [91/98] vs. 94.9% [93/98], p = 0.155). For histopathologically confirmed lesions, arterial subtraction images significantly increased sensitivity to 68.8% (128/186) from the 61.3% (114/186) of ordinary arterial-phase images (p <0.001), with a minimal decrease in specificity to 84.8% (39/46) from 89.1% (41/46) (p = 0.151). CONCLUSIONS: Arterial subtraction images of gadoxetate disodium-enhanced MRI can significantly improve the sensitivity of early-stage HCC diagnosis using LI-RADS, without a significant decrease in specificity. LAY SUMMARY: Gadoxetate disodium-enhanced magnetic resonance imaging is an imaging technique with a high sensitivity for the diagnosis of hepatocellular carcinoma. However, arterial-phase images may be unsatisfactory because of weak arterial enhancement. We found that using arterial subtraction images led to clinically meaningful improvements in the diagnosis of early-stage hepatocellular carcinoma.

Whole tumor ablation of locally recurred hepatocellular carcinoma including retained iodized oil after transarterial chemoembolization improves progression-free survival.

OBJECTIVES: To evaluate and compare clinical outcomes of two different radiofrequency ablation (RFA) methods for locally recurred hepatocellular carcinoma (LrHCC) after locoregional treatment. METHODS: Our institutional review board approved this study with a waiver of informed consent. A total of 313 patients previously treated with transarterial chemoembolization (TACE) (n = 167) and RFA (n = 146) with a single LrHCC ≤ 3 cm was included from five tertiary referral hospitals. RFA was done for LrHCCs using either viable tumor alone ablation (VTA) method (VTA: n = 61 in the TACE group and n = 127 in the RFA group) or whole tumor ablation (WTA) method which includes both viable tumor and retained iodized oil or previously ablated zone (WTA: n = 106 in the TACE group and n = 19 in the RFA group). Local tumor progression (LTP)-free survival as well as progression-free survival (PFS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated using the Cox proportional hazards regression model. RESULTS: In 167 patients with LrHCC who underwent TACE, the 5-year LTP-free survival after RFA was significantly higher with the VTA method than with the WTA method (26.9% vs. 87.8%; p < 0.001; hazard ratio (HR) = 8.53 [4.16-17.5]). The estimated 5-year PFS after RFA for LrHCC after TACE using the VTA method was 5.7%, which was significantly lower than that with the WTA method (26.4%) (p = 0.014; HR = 1.62 [1.10-2.38]). However, in 146 patients with LrHCC after initial RFA, there were no significant differences in cumulative incidence of LTP (p = 0.514) or PFS (p = 0.905) after RFA between the two ablation methods. CONCLUSIONS: For RFA of LrHCC after TACE, the WTA method including both viable tumor and retained iodized oil could significantly lower LTP and improve PFS than VTA. KEY POINTS: • Whole tumor ablation (WTA) could provide significantly better local tumor control for locally recurred HCC (LrHCC) after TACE than viable tumor alone ablation (VTA). • WTA for LrHCC after TACE could also provide significantly better progression-free survival than VTA. • Regarding LrHCC after RFA, VTA would provide a comparable clinical outcome to WTA.