Predicting Infectious Complications after Percutaneous Thermal Ablation of Liver Malignancies: A 12-year Single-Center Experience.

Background Infectious complications after percutaneous thermal ablation are seldom discussed, but better understanding of risk factors and early prediction is critical. Purpose To estimate the incidence of infectious complications after percutaneous thermal ablation of liver malignancies and to develop prediction models. Materials and Methods This single-center retrospective study reviewed the data of 3167 patients who underwent 7545 percutaneous US-guided thermal ablation procedures of liver malignancies between January 2010 and January 2022. All procedures with infectious complications were included as the case group. For each case, one treatment date-matched control subject without infection was randomly selected following a nested case-control design. Independent factors of overall and hepatobiliary infection were investigated with multivariable logistic regression. Results A total of 80 patients (median age, 59 years; IQR, 51-68 years; 64 men, 16 women) developed infectious complications after 80 ablation procedures; the incidence was 1.1% (80 of 7545 procedures). Of those with infection, 18% (14 of 80 patients) were severe, and 10% (eight of 80 patients) died as a result. Independent risk factors for overall infectious complication included prior biliary intervention (odds ratio [OR], 18.6; 95% CI: 4, 86; P < .001), prior transarterial chemoembolization (TACE) (OR, 2.4; 95% CI: 1.0, 5.8; P = .045), and the largest tumor size (OR, 1.9; 95% CI: 1.3, 2.8; P = .002); on this basis, subcapsular location was an additional risk factor of hepatobiliary infection. Prediction models for overall and hepatobiliary infection had an area under the receiver operating characteristics curve (AUC) of 0.77 and 0.82, respectively, both of which showed better AUC compared with the models, including prior biliary intervention alone (AUC = 0.63 and 0.65, respectively; P = .01 and P = .005, respectively). Conclusion Infectious complications after percutaneous thermal ablation of liver malignancies were uncommon but potentially fatal. Independent predictors were prior biliary intervention, prior transarterial chemoembolization, and the largest tumor size. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Ben-Arie and Sosna in this issue.

Predicting symptomatic post-hepatectomy liver failure in patients with hepatocellular carcinoma: development and validation of a preoperative nomogram.

OBJECTIVE: To develop and validate a nomogram based on liver stiffness (LS) for predicting symptomatic post-hepatectomy (PHLF) in patients with hepatocellular carcinoma (HCC). METHODS: A total of 266 patients with HCC were enrolled prospectively from three tertiary referral hospitals from August 2018 to April 2021. All patients underwent preoperative laboratory examination to obtain parameters of liver function. Two-dimensional shear wave elastography (2D-SWE) was performed to measure LS. Three-dimensional virtual resection obtained the different volumes including future liver remnant (FLR). A nomogram was developed by using logistic regression and determined by receiver operating characteristic (ROC) curve analysis and calibration curve analysis, which was validated internally and externally. RESULTS: A nomogram was constructed with the following variables: FLR ratio (FLR of total liver volume), LS greater than 9.5 kPa, Child-Pugh grade, and the presence of clinically significant portal hypertension (CSPH). This nomogram enabled differentiation of symptomatic PHLF in the derivation cohort (area under curve [AUC], 0.915), internal fivefold cross-validation (mean AUC, 0.918), internal validation cohort (AUC, 0.876) and external validation cohort (AUC, 0.845). The nomogram also showed good calibration in the derivation, internal validation, and external validation cohorts (Hosmer-Lemeshow goodness-of-fit test, p = 0.641, p = 0.06, and p = 0.127, respectively). Accordingly, the safe limit of the FLR ratio was stratified using the nomogram. CONCLUSION: An elevated level of LS was associated with the occurrence of symptomatic PHLF in HCC. A preoperative nomogram integrating LS, clinical and volumetric features was useful in predicting postoperative outcomes in patients with HCC, which might help surgeons in the management of HCC resection. CLINICAL RELEVANCE STATEMENT: A serial of the safe limit of the future liver remnant was proposed by a preoperative nomogram for hepatocellular carcinoma, which might help surgeons in 'how much remnant is enough in liver resection'. KEY POINTS: • An elevated liver stiffness with the best cutoff value of 9.5 kPa was associated with the occurrence of symptomatic post-hepatectomy liver failure in hepatocellular carcinoma. • A nomogram based on both quality (Child-Pugh grade, liver stiffness, and portal hypertension) and quantity of future liver remnant was developed to predict symptomatic post-hepatectomy liver failure for HCC, which enabled good discrimination and calibration in both derivation and validation cohorts. • The safe limit of future liver remnant volume was stratified using the proposed nomogram, which might help surgeons in the management of HCC resection.

US LI-RADS in surveillance for recurrent hepatocellular carcinoma after curative treatment.

OBJECTIVES: To investigate the performance of US LI-RADS in surveillance for recurrent hepatocellular carcinoma (RHCC) after curative treatment. MATERIALS AND METHODS: This study enrolled 644 patients between January 2018 and August 2018 as a derivation cohort, and 397 patients from September 2018 to December 2018 as a validation cohort. The US surveillance after HCC curative treatment was performed. The US LI-RADS observation categories and visualization scores were analyzed. Four criteria using US LI-RADS or Alpha-fetoprotein (AFP) as the surveillance algorithm were evaluated. The sensitivity, specificity, and negative predictive value (NPV) were calculated. RESULTS: A total of 212 (32.9%) patients in derivation cohort and 158 (39.8%) patients in validation cohort were detected to have RHCCs. The criterion of US-2/3 or AFP ≥ 20 µg/L had higher sensitivity (derivation, 96.7% vs 92.9% vs 81.1% vs 90.6%; validation, 96.2% vs 90.5% vs 80.4% vs 89.9%) and NPV (derivation, 95.7% vs 93.3% vs 88.0% vs 91.8%; validation, 94.6% vs 89.4% vs 83.6% vs 89.0%), but lower specificity (derivation, 35.9% vs 48.2% vs 67.6% vs 51.9%; validation, 43.5% vs 52.7% vs 66.1% vs 54.0%) than criterion of US-2/3, US-3, and US-3 or AFP ≥ 20 µg/L. Analysis of the visualization score subgroups confirmed that the sensitivity (89.2-97.6% vs 81.0-83.3%) and NPV(88.4-98.0% vs 80.0-83.3%) of score A and score B groups were higher than score C group in criterion of US-2/3 in both two cohorts. CONCLUSIONS: In the surveillance for RHCC, US LI-RADS with AFP had a high sensitivity and NPV when US-2/3 or AFP ≥ 20 µg/L was considered a criterion. CLINICAL RELEVANCE STATEMENT: The criterion of US-2/3 or AFP ≥ 20 µg/L improves sensitivity and NPV for RHCC surveillance, which provides a valuable reference for patients in RHCC surveillance after curative treatment. KEY POINTS: • US LI-RADS with AFP had high sensitivity and NPV in surveillance for RHCC when considering US-2/3 or AFP ≥ 20 µg/L as a criterion. • After US with AFP surveillance, patients with US-2/3 or AFP ≥ 20 µg/L should perform enhanced imaging for confirmative diagnosis. Patients with US-1 or AFP < 20 µg/L continue to repeat US with AFP surveillance. • Patients with risk factors for poor visualization scores limited the sensitivity of US surveillance in RHCC.

Shear-wave elastography combined with contrast-enhanced ultrasound algorithm for noninvasive characterization of focal liver lesions.

PURPOSE: To establish shear-wave elastography (SWE) combined with contrast-enhanced ultrasound (CEUS) algorithm (SCCA) and improve the diagnostic performance in differentiating focal liver lesions (FLLs). MATERIAL AND METHODS: We retrospectively selected patients with FLLs between January 2018 and December 2019 at the First Affiliated Hospital of Sun Yat-sen University. Histopathology was used as a standard criterion except for hemangiomas and focal nodular hyperplasia. CEUS with SonoVue (Bracco Imaging) and SCCA combining CEUS and maximum value of elastography with < 20 kPa and > 90 kPa thresholds were used for the diagnosis of FLLs. The diagnostic performance of CEUS and SCCA was calculated and compared. RESULTS: A total of 171 FLLs were included, with 124 malignant FLLs and 47 benign FLLs. The area under curve (AUC), sensitivity, and specificity in detecting malignant FLLs were 0.83, 91.94%, and 74.47% for CEUS, respectively, and 0.89, 91.94%, and 85.11% for SCCA, respectively. The AUC of SCCA was significantly higher than that of CEUS (P = 0.019). Decision curves indicated that SCCA provided greater clinical benefits. The SCCA provided significantly improved prediction of clinical outcomes, with a net reclassification improvement index of 10.64% (P = 0.018) and integrated discrimination improvement of 0.106 (P = 0.019). For subgroup analysis, we divided the FLLs into a chronic-liver-disease group (n = 88 FLLs) and a normal-liver group (n = 83 FLLs) according to the liver background. In the chronic-liver-disease group, there were no differences between the CEUS-based and SCCA diagnoses. In the normal-liver group, the AUC of SCCA and CEUS in the characterization of FLLs were 0.89 and 0.83, respectively (P = 0.018). CONCLUSION: SCCA is a feasible tool for differentiating FLLs in patients with normal liver backgrounds. Further investigations are necessary to validate the universality of this algorithm.

High-Frequency US for BK Polyomavirus-associated Nephropathy after Kidney Transplant.

Background BK polyomavirus-associated nephropathy (BKPyVAN) is an important cause of chronic renal allograft dysfunction. However, US features indicative of BKPyVAN have not been fully evaluated. Purpose To assess the value of high-frequency US for the diagnosis of BKPyVAN in kidney transplant recipients. Materials and Methods In this prospective cohort study, participants who tested positive for BK viruria after kidney transplant from September 2019 to January 2021 were evaluated with high-frequency US 1 day before biopsy. Clinical characteristics and US features were compared between participants with and without BKPyVAN. Significant predictors associated with BKPyVAN were determined using logistic regression analyses. The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Results A total of 105 participants who underwent kidney transplant (mean age, 38 years ± 11 [SD]; 63 men) were evaluated; 45 participants were diagnosed with BKPyVAN. Multivariable analysis demonstrated that eccentric hydronephrosis and subcapsular hypoechoic areas were independent factors for BKPyVAN. The AUC for predicting BKPyVAN according to subcapsular hypoechoic areas was 0.66 (95% CI: 0.55, 0.77), with a specificity of 92% (55 of 60 participants). The AUC of combined US (eccentric hydronephrosis plus subcapsular hypoechoic area) and clinical (urine BKPyV DNA load [BKPyV-DNA] plus BK viremia) features was 0.90, with a specificity of 92% (55 of 60 participants). Parenchymal hyperechoic and subcapsular hypoechoic areas were independent factors for differentiating BKPyVAN from transplant rejection. The pooled specificity of subcapsular hypoechoic areas was 96% (21 of 22 participants), with an AUC of 0.67 (95% CI: 0.54, 0.80). For the combination of US (parenchymal echogenicity plus subcapsular hypoechoic area) and clinical (urine BKPyV-DNA plus time since transplant) features, the AUC reached 0.92 and specificity was 82% (18 of 22 participants). Conclusion High-frequency US characteristics are valuable for diagnosing BK polyomavirus-associated nephropathy (BKPyVAN) and distinguishing BKPyVAN from rejection in kidney transplant recipients. © RSNA, 2022 Online supplemental material is available for this article.

Role of Preoperational Imaging Traits for Guiding Treatment in Single ≤ 5 cm Hepatocellular Carcinoma.

BACKGROUND: Imaging traits including nonsmooth tumor margins, internal arteries, peritumoral enhancement, and absence of hypodense halos can reflect tumor aggressiveness preoperatively and may affect treatment selection. This study aimed to explore the role of these four imaging traits in treatment selection between surgical resection (SR) and radiofrequency ablation (RFA) for patients with single ≤ 5 cm hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Three hundred eight-one patients with single ≤ 5 cm HCC who underwent SR (n = 202) or RFA (n = 179) in the First Affiliated Hospital of Sun Yat-sen University from April 2010 to December 2019 were retrospectively enrolled. The efficacy of SR and RFA in patients with the imaging traits that significantly influenced recurrence-free survival (RFS) or overall survival (OS) was compared and analyzed. RESULTS: Multivariable Cox regression analysis identified that having internal arteries (P = 0.001) was an independent influencing factor for RFS, while internal arteries (P = 0.005) and peritumoral enhancement (P = 0.001) were independent influencing factors for OS. In patients with internal arteries, subgroup analysis based on tumor size demonstrated that both RFS and OS of SR were superior to those of RFA in patients with 3-5 cm HCC (RFS, P = 0.023; OS, P = 0.015). In patients with peritumoral enhancement, both RFS and OS of SR were superior to those of RFA (RFS, P = 0.019; OS, P = 0.042). CONCLUSION: SR may be associated with improved survival compared with RFA in patients with single 3-5 cm HCC having internal arteries and patients with single ≤ 5 cm HCC having peritumoral enhancement.

Liver Stiffness Measured by Two-Dimensional Shear Wave Elastography for Predicting Symptomatic Post-hepatectomy Liver Failure in Patients with Hepatocellular Carcinoma.

OBJECTIVES: To evaluate the ability of liver stiffness (LS) measured by two-dimensional shear wave elastography (2D SWE) to predict symptomatic post-hepatectomy liver failure (SPHLF) in patients with hepatocellular carcinoma (HCC). METHODS: A total of 119 patients who underwent hepatectomy for HCC between August 2018 and July 2019 were enrolled. Preoperative assessments for LS and other clinicopathological tests were performed in all patients. Univariate and multivariate analyses were conducted for the risk factors of SPHLF. Further subgroup analysis was performed according to multivariate analysis results. RESULTS: SPHLF occurred in 38 patients (31.9%). The best cutoff value of LS for predicting SPHLF was 9.5 kPa. Multivariate analysis identified LS ≥ 9.5 kPa, greater Child-Turcotte-Pugh (CTP) grade, and major hepatectomy as independent predictors of SPHLF. Based on the extent of hepatectomy, CTP grade could stratify the risk of SPHLF in the minor hepatectomy group (12.2% vs. 100.0%, p = 0.001), whereas LS was superior in predicting SPHLF in the major hepatectomy group (18.9% vs. 72.4%, p < 0.001). In patients with CTP grade A, LS could further stratify the risks of SPHLF in both the minor and major hepatectomy groups (3.7% vs. 22.7%, p = 0.043; 17.6% vs. 70.4%, p < 0.001, respectively). CONCLUSIONS: LS measured using 2D SWE could predict SPHLF using the best cutoff value of 9.5 kPa. CTP grade was a stronger indicator of SPHLF in minor hepatectomy, whereas LS was more effective in selecting candidates for major hepatectomy. LS could further stratify the risk of SPHLF in CTP grade A patients, regardless of the extent of hepatectomy.

Ultrasound-guided percutaneous radiofrequency ablation in treatment of neuroendocrine tumor liver metastases：a single-center experience.

PURPOSE: To investigate the local tumor control of ultrasound-guided percutaneous radiofrequency ablation (RFA) in treating neuroendocrine tumor liver metastases (NETLM). MATERIALS AND METHODS: From March 2011 to December 2020, 23 patients with 39 NETLM treated with percutaneous RFA were studied. The study assessed the therapeutic outcomes after RFA, including the rates of technical success, technical efficacy, major complications, local tumor progression (LTP) and overall survival. Cumulative LTP rates were estimated with the Kaplan-Meier method. RESULTS: The technical efficacy rate was 91.3% (21/23) at one month after RFA. No major complication occurred in the treatment. LTP occurred in 50% (11/22) of patients who had complete ablation, with a median progression-free survival time of 15 months (1-61 months). Patients with Ki-67 < 5% had a longer progression-free survival than those with Ki-67 ≥ 5% (22.0 vs. 3.5 months, p<.001). Four patients, who had sporadic recurrent liver metastases, received 1-6 times of additional RFA after the initial treatment. Twenty patients were alive at the end of this study, except three patients withdrawn. The overall survival was at a median of 48 months (9-182 months). CONCLUSION: RFA provides effective local tumor control with low morbidity and it can be applied repeatedly over years to control recurrence of NETLM. Patients with Ki-67 < 5% have better local tumor control with percutaneous RFA of NETLM.

The role of neoadjuvant conventional transarterial chemoembolization with radiofrequency ablation in the treatment of recurrent hepatocellular carcinoma after initial hepatectomy with microvascular invasion.

OBJECTIVES: Recurrent hepatocellular carcinoma (HCC) patients with microvascular invasion (MVI)-positive primary tumor is at high risk of re-recurrence while treated with radiofrequency ablation (RFA). We aimed to investigate whether neoadjuvant conventional transarterial chemoembolization (cTACE) was effective in reducing re-recurrence after RFA for recurrent HCC patients with MVI-positive primary tumors. METHODS: In this retrospective multicenter study, 468 patients with solitary small recurrent HCC (≤3.0cm) underwent RFA alone (n = 322) or with neoadjuvant cTACE (n = 146) between June 2007 and December 2017 were included. Overall survival (OS) and recurrence-free survival (RFS) were compared. RESULTS: The 1-, 5-year OS rates were 74.8%, 42.5% for RFA with neoadjuvant cTACE group, and 53.5%, 28.7% for RFA group (P < 0.001). The corresponding RFS rates were 51.7%, 24.4% for RFA with neoadjuvant cTACE group, and 36.1%, 9.3% for RFA group (P < 0.001). In subgroup analyses, the OS and RFS for neoadjuvant cTACE group were longer than those for RFA group no matter tumor size > 2cm (HR = 0.52, 95% CI: 0.36-0.77; HR = 0.49, 95% CI: 0.36-0.67) or not (HR = 0.53, 95% CI: 0.32-0.88; HR = 0.65, 95% CI: 0.42-0.98), or the time interval of recurrence from initial treatment ≤ 1 year (HR = 0.53, 95% CI: 0.36-0.77; HR = 0.70, 95% CI: 0.52-0.94) or not (HR = 0.56, 95% CI: 0.34-0.95; HR = 0.39, 95% CI: 0.25-0.62). Multivariable analyses showed that RFA alone (HR = 1.329, P = 0.031; HR = 1.764, P = 0.004) and interval of recurrence from initial treatment > 1 year(HR = 0.642, P = 0.001; HR = 0.298, P = 0.037) were independent prognostic factors of OS and RFS. CONCLUSIONS: Neoadjuvant cTACE could effectively reduce re-recurrence after RFA, and improve the long-term survivals for patients with solitary small recurrent HCC whose primary tumor was MVI-positive. Key pointsFor recurrent hepatocellular carcinoma (HCC) patients whose primary tumor was positive for microvascular invasion, neoadjuvant conventional transarterial chemoembolization (cTACE) with radiofrequency ablation (RFA) achieved better efficacy.Multivariable analyses showed that the interval of recurrence from initial treatment > 1 year and RFA alone were independent prognostic factors of overall survival and recurrence-free survival, respectively.

Preoperative prognostic value of alfa-fetoprotein density in patients with hepatocellular carcinoma undergoing radiofrequency ablation.

OBJECTIVES: To examine the prognostic value of preoperative alfa-fetoprotein (AFP) density and other clinical factors in patients undergoing percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). METHODS: From January 2010 to December 2018, a total of 543 patients undergoing RFA for HCC meeting the Milan criteria were included at our institution. AFP density was calculated as absolute AFP pre-ablation divided by the total volume of all HCC lesions. The survival rates according to AFP density were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate Cox proportional-hazards regression analyses were used to assess predictors of overall survival (OS) and progression-free survival (PFS). RESULTS: The Kaplan-Meier 1-, 3-, and 5-year OS rates were 98.8%, 88.5%, and 70.4%, respectively, for the low AFP density group, and 98.3%, 74.9%, and 49.4%, respectively, for the high AFP density group. The corresponding PFS rates were 78.9%, 56.7%, and 40.9% (low AFP density group), and 63.6%, 40.8%, and 27.5% (high AFP density group). High AFP density was associated with significantly reduced PFS and OS (both p < 0.001). Multivariate analysis suggested that AFP density was a predictor of OS and PFS. CONCLUSIONS: Serum AFP density may serve as a promising predictor of survival in patients with HCC undergoing RFA. High AFP density could identify patients who might be prone to recurrence or progression and need close surveillance.

Identification of the origin of tumor in vein: comparison between CEUS LI-RADS v2017 and v2016 for patients at high risk.

OBJECTIVES: To compare the diagnostic performance of the Contrast-Enhanced Ultrasound (CEUS) Liver Imaging Report and Data System (LI-RADS) v2016 and v2017 in identifying the origin of tumor in vein (TIV). METHODS: From April 2014 to December 2018, focal liver lesions (FLLs) accompanied by TIV formation in patients at high risk for hepatocellular carcinoma (HCC) were enrolled. Histologic evaluation or composite imaging reference standard were served as the reference standard. Each case was categorized according to the CEUS LI-RADS v2016 and v2017, respectively. Diagnostic performance of CEUS LI-RADS v2016 and v2017 in identifying the originated tumor of TIV was validated via sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value. RESULTS: A total of 273 FLLs with TIV were analyzed finally, including 266 HCCs and 7 non-HCCs. In v2016, when adopting all TIV as LR-5V, the accuracy and PPV in identifying the originated tumor were both 97.4%. In v2017, when assigning TIV according to contiguous FLLs CEUS LI-RADS category, the accuracy and PPV were 61.9% and 99.4% in subclass of LR-5 as the diagnostic criteria of HCC, and 64.1% and 99.4% in subclass of LR-4/5 as the criteria of HCC diagnosis. There were significant differences in diagnostic accuracy between CEUS LI-RADS v2016 and v2017 in identifying the originated tumor of TIV (p < 0.001). CONCLUSIONS: CEUS LI-RADS v2016 could be better than v2017 in identifying the originated tumor of TIV.

Transcriptome and Metabolome Profiling Reveal the Resistance Mechanisms of Rice against Brown Planthopper.

Brown planthopper (Nilaparvata lugens Stål, BPH) is one of the most destructive insects affecting rice production. To better understand the physiological mechanisms of how rice responds to BPH feeding, we analyzed BPH-induced transcriptomic and metabolic changes in leaf sheaths of both BPH-susceptible and -resistant rice varieties. Our results demonstrated that the resistant rice reduced the settling, feeding and growth of BPH. Metabolic analyses indicated that BPH infestation caused more drastic overall metabolic changes in the susceptible variety than the resistant rice. Differently accumulated metabolites (DAMs) belonging to flavonoids were downregulated in the susceptible rice but upregulated in resistant variety. Transcriptomic analyses revealed more differentially expressed genes (DEGs) in susceptible rice than resistant rice, and DEGs related to stimulus were significantly upregulated in resistant rice but downregulated in susceptible rice. Combined analyses of transcriptome and metabolome showed that many DEGs and DAMs were enriched in phenylpropane biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction. We conducted correlation analyses of DEGs and DAMs in these pathways and found a high correlation between DEGs and DAMs. Then, we found that the contents of endogenous indole 3-acetic acid (IAA) in resistant rice was lower than that of susceptible rice after BPH feeding, while the salicylic acid (SA) content was the opposite. For functional analysis, an exogenous application of IAA decreased rice resistance to BPH, but the exogenous application of SA increased resistance. In addition, biochemical assessment and quantitative PCR analysis showed that the lignin content of resistant accession was constitutively higher than in susceptible accession. By adding epigallocatechin, the substrate of anthocyanidin reductase (ANR), to the artificial diet decreased the performance of BPH. We first combined a transcriptome-metabolome-wide association study (TMWAS) on rice resistance to BPH in this study. We demonstrated that rice promoted resistance to BPH by inducing epigallocatechin and decreasing IAA. These findings provided useful transcriptomic and metabolic information for understanding the rice-BPH interactions.

Inter-reader agreement of CEUS LI-RADS among radiologists with different levels of experience.

OBJECTIVES: To investigate the inter-reader agreement of contrast-enhanced ultrasound (CEUS) of Liver Imaging Reporting and Data System version 2017 (LI-RADS v2017) categories among radiologists with different levels of experience. MATERIALS AND METHODS: From January 2014 to December 2014, a total of 326 patients at high risk of hepatocellular carcinoma (HCC) who underwent CEUS were included in this retrospective study. All lesions were classified according to LI-RADS v2017 by six radiologists with different levels of experiences: two residents, two fellows, and two specialists. Kappa coefficient was used to assess consistency of LI-RADS categories and major features among radiologists with different levels of experience. The diagnostic performance of HCC was described by accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC). RESULTS: Inter-reader agreement among radiologists of different experience levels was substantial agreement for arterial phase hyperenhancement, washout appearance, and early or late washout. Inter-reader agreement for LI-RADS categories was moderate to substantial. When LR-5 was used as criteria to determinate HCC, the AUC of LI-RADS for HCC was 0.67 for residents, 0.72 for fellows, and 0.78 for specialist radiologists. When compared between residents and specialists, accuracy, sensitivity, and AUC were significantly different (all p < 0.05). However, there were no significant differences in specificity, PPV, and NPV between the two groups. CONCLUSION: CEUS LI-RADS showed good diagnostic consistency among radiologists with different levels of experience, and consistency increased with experience levels. KEY POINTS: • The inter-reader agreement for LI-RADS categories was moderate to substantial agreement (κ, 0.60-0.80). • When compared between residents and specialists, accuracy, sensitivity, and AUC showed significantly different (all p < 0.05). However, there were no significant differences for specificity, PPV, and NPV between these two groups. • Among the radiologists with more than 1 year of experience, there was no significant difference in the diagnostic performance of HCC, suggesting that CEUS LI-RADS is a good standardized categorization system for high-risk patients.

Percutaneous thermal ablation of hepatic tumors: local control efficacy and risk factors for artificial ascites failure.

OBJECTIVE: To investigate the risk factors affecting the technical failure of artificial ascites (AA) formation and to evaluate the local control efficacy of percutaneous thermal ablation assisted by the AA for hepatic tumors. METHODS: A total of 341 patients with 362 hepatic tumors who underwent thermal ablation assisted by AA were reviewed retrospectively. The technical success of AA, the volume of liquid, and local efficacy after ablation were assessed. Predictive factors for the technical failure of AA formation and local tumor progression (LTP) were analyzed using univariate and multivariate analysis. RESULTS: The technical success rate of AA formation was 81.8% (296/362). The amount of fluid was higher when the tumor was located in the left lobe of the liver than when it was located in the right lobe (median 950 ml versus 700 ml, p < 0.001). Previous hepatic resection (OR: 12.63, 95% CI: 2.93-54.45, p < 0.001), ablation (OR: 6.48, 95% CI: 1.36-30.92, p = 0.019) and upper-abdomen surgery (OR: 11.34, 95% CI: 1.96-65.67, p = 0.007) were the independent risk factors of AA failure. In the AA success group, the complete ablation rate was higher and the LTP rate was lower than that in the AA failure group (98.7 versus 92.4%, p = 0.012; 8.8 versus 21.2%, p = 0.004). Multivariate analysis identified AA failure (p = 0.004), tumor size (>3.0 cm) (p = 0.002) and metastatic liver tumor (p = 0.008) as independent risk factors for LTP. CONCLUSION: History of hepatic resection, ablation and upper abdomen surgery were significant predictive factors affecting the technical failure of AA formation. Successful introduction of AA before thermal ablation can achieve better local tumor control efficacy.

Differentiation of regenerative nodule, dysplastic nodule, and small hepatocellular carcinoma in cirrhotic patients: a contrast-enhanced ultrasound-based multivariable model analysis.

OBJECTIVE: To develop a contrast-enhanced ultrasound (CEUS)-based model for differentiating cirrhotic liver lesions and for active surveillance of hepatocellular carcinoma (HCC). METHODS: Patients with focal liver lesions (FLLs) with biopsy/resection-proven pathology and pre-procedure CEUS were enrolled from our institution between January 2011 and November 2014. Univariable and multivariable regression models were constructed using qualitative CEUS features and/or contrast arrival time ratio (CATR). The optimism-adjusted Harrell's generalized concordance index (CH) was used to quantify the discriminatory ability of each CEUS feature and model. RESULTS: A total of 149 patients (113 men and 36 women) with 162 FLLs were enrolled with mean age 53.4 ± 12.7 years. A 0.1-unit reduction in CATR was associated with a 68% increase in the odds of having a higher nodule ranking (RN < DN < small HCC) (OR, 0.32; 95% CI, 0.20-0.50, p < .001). Arterial phase hypoenhancement and isoenhancement were inversely associated with a higher nodule ranking compared to hyperenhancement. Late-phase isoenhancement was associated with lower odds of a higher nodule ranking. The CEUS + CATR model (CH 0.92, 0.89-0.95) provided greater discriminatory ability when compared to the CATR model (ΔCH 0.09, 0.04-0.13, p < .001) and the CEUS model (ΔCH 0.03, 0.01-0.05, p = .02). CONCLUSIONS: Our results provide preliminary evidence that multivariable regression model constructed using both qualitative CEUS features and CATR provides the greatest discriminatory ability to differentiate RN, DN, and small HCC in patients with cirrhosis, and might allow for active surveillance of the progression of cirrhotic liver lesions. KEY POINTS: • Proportional odds logistic regression models based on qualitative CEUS features and/or CATR can be used for differentiating cirrhotic liver lesions and for active surveillance of HCC. • The reduction of CATR (RN < DN < small HCC) was strongly associated with high-risk cirrhotic liver nodules. • Inclusion of CATR in the CEUS prediction model significantly improved its performance for cirrhotic liver lesions risk-stratification.

Accurate prediction of responses to transarterial chemoembolization for patients with hepatocellular carcinoma by using artificial intelligence in contrast-enhanced ultrasound.

OBJECTIVES: We aimed to establish and validate an artificial intelligence-based radiomics strategy for predicting personalized responses of hepatocellular carcinoma (HCC) to first transarterial chemoembolization (TACE) session by quantitatively analyzing contrast-enhanced ultrasound (CEUS) cines. METHODS: One hundred and thirty HCC patients (89 for training, 41 for validation), who received ultrasound examination (CEUS and B-mode) within 1 week before the first TACE session, were retrospectively enrolled. Ultrasonographic data was used for building and validating deep learning radiomics-based CEUS model (R-DLCEUS), machine learning radiomics-based time-intensity curve of CEUS model (R-TIC), and machine learning radiomics-based B-Mode images model (R-BMode), respectively, to predict responses (objective-response and non-response) to TACE with reference to modified response evaluation criteria in solid tumor. The performance of models was compared by areas under the receiver operating characteristic curve (AUC) and the DeLong test was used to compare different AUCs. The prediction robustness was assessed for each model. RESULTS: AUCs of R-DLCEUS, R-TIC, and R-BMode were 0.93 (95% CI, 0.80-0.98), 0.80 (95% CI, 0.64-0.90), and 0.81 (95% CI, 0.67-0.95) in the validation cohort, respectively. AUC of R-DLCEUS shows significant difference compared with that of R-TIC (p = 0.034) and R-BMode (p = 0.039), whereas R-TIC was not significantly different from R-BMode. The performance was highly reproducible with different training and validation cohorts. CONCLUSIONS: DL-based radiomics method can effectively utilize CEUS cines to achieve accurate and personalized prediction. It is easy to operate and holds good potential for benefiting TACE candidates in clinical practice. KEY POINTS: • Deep learning (DL) radiomics-based CEUS model can accurately predict responses of HCC patients to their first TACE session by quantitatively analyzing their pre-operative CEUS cines. • The visualization of the 3D CNN analysis adopted in CEUS model provided direct insight into what computers "see" on CEUS cines, which can help people understand the interpretation of CEUS data. • The proposed prediction method is easy to operate and labor-saving for clinical practice, facilitating the clinical treatment decision of HCCs with very few time costs.

Preoperative prediction of tumour deposits in rectal cancer by an artificial neural network-based US radiomics model.

OBJECTIVE: To develop a machine learning-based ultrasound (US) radiomics model for predicting tumour deposits (TDs) preoperatively. METHODS: From December 2015 to December 2017, 127 patients with rectal cancer were prospectively enrolled and divided into training and validation sets. Endorectal ultrasound (ERUS) and shear-wave elastography (SWE) examinations were conducted for each patient. A total of 4176 US radiomics features were extracted for each patient. After the reduction and selection of US radiomics features , a predictive model using an artificial neural network (ANN) was constructed in the training set. Furthermore, two models (one incorporating clinical information and one based on MRI radiomics) were developed. These models were validated by assessing their diagnostic performance and comparing the areas under the curve (AUCs) in the validation set. RESULTS: The training and validation sets included 29 (33.3%) and 11 (27.5%) patients with TDs, respectively. A US radiomics ANN model was constructed. The model for predicting TDs showed an accuracy of 75.0% in the validation cohort. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and AUC were 72.7%, 75.9%, 53.3%, 88.0% and 0.743, respectively. For the model incorporating clinical information, the AUC improved to 0.795. Although the AUC of the US radiomics model was improved compared with that of the MRI radiomics model (0.916 vs. 0.872) in the 90 patients with both ultrasound and MRI data (which included both the training and validation sets), the difference was nonsignificant (p = 0.384). CONCLUSIONS: US radiomics may be a potential model to accurately predict TDs before therapy. KEY POINTS: • We prospectively developed an artificial neural network model for predicting tumour deposits based on US radiomics that had an accuracy of 75.0%. • The area under the curve of the US radiomics model was improved than that of the MRI radiomics model (0.916 vs. 0.872), but the difference was not significant (p = 0.384). • The US radiomics-based model may potentially predict TDs accurately before therapy, but this model needs further validation with larger samples.

Cirrhotic Nodule Transformation to Hepatocellular Carcinoma: Natural History and Predictive Biomarkers on Contrast-Enhanced Ultrasound.

OBJECTIVE. The objective of our study was to identify sonographic biomarkers predicting or indicating eventual malignant transformation of pathologically confirmed cirrhotic nodules. MATERIALS AND METHODS. Thirty-nine consecutive patients with 44 pathologically confirmed cirrhotic nodules (mean size, 17.5 ± 8.5 [SD] mm) who initially underwent contrast-enhanced ultrasound examination at detection and then underwent follow-up conventional ultrasound every 3-4 months thereafter were retrospectively included. Malignant transformation was identified on the basis of noninvasive diagnostic criteria for hepatocellular carcinoma or rebiopsy. Malignant transformation biomarkers were identified from clinical and sonographic variables and the performance thereof was evaluated using ROC curves. RESULTS. Fourteen nodules (31.8%) had eventual malignant transformation after a median follow-up time of 26.7 months. At initial detection, nodule size (hazard ratio [HR], 1.07; p = 0.019) and a contrast arrival time difference between the nodule and liver of more than 0.5 second (HR, 4.35; p = 0.011) were independent predictors for malignant transformation. The area under the ROC curve (Az) of initial nodule size (Az = 0.64, p = 0.131) and contrast arrival time difference between the nodule and liver (Az = 0.66, p = 0.029) improved after combining the two (Az = 0.75, p = 0.002). During follow-up, echogenicity change (p = 0.044), absolute growth rate (p < 0.001), and relative growth rate (p < 0.001) correlated with malignant transformation. Sensitivity analysis revealed that an absolute growth rate of 5 mm or greater in 6 months or a relative growth rate of 30% or greater in 6 months could be considered as threshold growth for identifying malignant transformation (specificity, 100.0%; positive predictive value, 100.0%). The absence of both echogenicity change and threshold growth was highly accurate in excluding malignant transformation (sensitivity, 100.0%; negative predictive value, 100.0%). CONCLUSION. The contrast arrival time difference between the nodule and liver at initial detection was useful in stratifying eventual malignant transformation risk for cirrhotic nodules. During follow-up, growth rate and echogenicity change correlated with malignant transformation; threshold growth on ultrasound may be considered a potential major feature in noninvasive diagnostic criteria of hepatocellular carcinoma.

Contrast-enhanced ultrasound-guided feeding artery ablation as add-on to percutaneous radiofrequency ablation for hypervascular hepatocellular carcinoma with a modified ablative technique and tumor perfusion evaluation.

OBJECTIVES: To establish a modified strategy of the feeding artery ablation (FAA) procedure as an add-on to percutaneous radiofrequency ablation (RFA) for patients with hypervascular hepatocellular carcinoma (HCC), and to evaluate the outcomes. MATERIALS AND METHODS: For this prospective, single-arm study, from June 2014 to August 2016, twenty-five patients with hypervascular HCC, 2-5 cm in diameter were treated by contrast-enhanced ultrasound (CEUS)-guided FAA before conventional RFA. Technical success of FAA and subsequent perfusion change of the tumor were evaluated by CEUS. Technical efficacy and ablation sizes were evaluated by CT/MRI at 1 month. Therapeutic outcomes, including local tumor progression (LTP), overall survival (OS), and recurrence-free survival (RFS) were evaluated using the Kaplan-Meier method. RESULTS: One or two target feeding arteries were visible on CEUS for 52.6% (61/116) of the hypervascular HCCs 2-5 cm in diameter. The technical success rate of the FAA was 100%; 13/25 (52.0%) target tumors were evaluated as complete perfusion response, while 12/25 (48.0%) were evaluated as partial perfusion response. The ablation volume was 41.9 ± 17.5 cm3 (14.9-78.2 cm3) and the ablative safety margin was 8.2 ± 1.9 mm (4-12 mm) at the 1-month evaluation. These parameters did not differ significantly between the complete and partial subgroups. The cumulative rates of LTP at 1-, 2-, and 3-year follow-ups were 0.0%, 4.2% and 4.2%, respectively. The 3-year OS and RFS were 70.3% vs. 59.8%, respectively. There were no treatment-related deaths. Major complications occurred in one patient (4.0%). CONCLUSION: As an add-on to conventional percutaneous RFA, tailored CEUS-guided FAA can reduce tumor perfusion and provide good local control of HCC.

Thermal ablation versus hepatic resection for the treatment of liver metastases from gastrointestinal stromal tumors: a retrospective study.

Objective: The study aimed to compare effectiveness and safety of thermal ablation and hepatic resection in patients with liver metastases of gastrointestinal stromal tumors (GISTs).Method: A total of 55 patients (27 in the ablation group and 28 in the surgery group) with liver metastases were included. Overall survival (OS) and progression-free survival (PFS) were assessed with Kaplan-Meier's survival estimate curves. Univariate and multivariate regression analyses were carried out to identify potential prognostic factors.Results: The median OS was 102.0 months in the ablation group and 117.0 months in the surgery group (p = .875). The 1-, 3- and 5-year OS rates were 100%, 88.9% and 74.1% in the ablation group and 92.8%, 82.1% and 78.6% in the surgery group, respectively. The 1-, 3- and 5-year PFS rates were 48.1%, 25.9% and 18.5% in the ablation group and 67.8%, 64.3% and 64.3% in the surgery group, respectively. Multivariate analysis showed that preoperative tyrosine kinase inhibitor (TKI) treatment (progressive disease, PD) (HR, 13.985; 95% CI, 1.791-109.187; p = .012) was the only significant independent prognostic factor for OS. Tumor number (HR, 1.318; 95% CI, 1.021-1.702; p = .034) was identified as an independent predictor for PFS in multivariate analysis. There were fewer postoperative complications (18.5% vs. 78.6%, p = .001) and shorter lengths of hospital stay (8.0 vs. 16.5 days, p = .001) in the ablation group.Conclusion: Compared with resection, thermal ablation offered comparable OS for liver metastases of GISTs. Furthermore, thermal ablation had the advantages of fewer complications and shorter lengths of hospital stay.