Sonic hedgehog hepatocellular adenoma: magnetic resonance imaging features and correlation with histology.

OBJECTIVES: Sonic hedgehog hepatocellular adenoma (shHCA) is a new hepatocellular adenoma (HCA) subgroup characterized by high risk of hemorrhage. ShHCA account for below 10% of all HCA cases and are often associated with female gender, obesity, and non-alcoholic steatohepatitis. No specific MRI characteristics have been described to date. The objective of this study was to assess the value of using MRI to identify shHCA, and correlate MRI findings with histology. METHODS: We retrospectively collected MRI scans of 29 patients with shHCA from our center and from different liver referral centers to include 35 lesions. Diagnosis of shHCA was assessed by immunohistochemical overexpression of argininosuccinate synthase 1 or prostaglandin D2 synthase, then confirmed by molecular analysis of sonic hedgehog pathway activation and/or by proteomic analysis. RESULTS: In 46% (n = 16/35) of shHCA cases, we detected intralesional fluid-filled cavities defined on MR images as fluid-like foci markedly hyperintense on T2-weighted sequences, and hypointense on T1-weighted sequences, with or without delayed enhancement. Pathologically, these cavities were observed in 54% of cases as vacuoles filled with blood at different stages of degradation. Hemorrhage and/or necrosis were detected among 71% of cases by MRI analysis (n = 25/35) versus 82% pathologically. Seventeen percent of shHCA cases (n = 6/35) were completely homogeneous via MRI and pathological analysis. No MRI criteria was found in favor of focal nodular hyperplasia, HNF1A-mutated HCA, or typical inflammatory HCA. CONCLUSION: We reveal the presence of intralesional fluid-filled cavities among 46% of our shHCA cases that represent a new MRI finding possibly helpful for shHCA diagnosis. CLINICAL RELEVANCE STATEMENT: This multicenter study is the first clinical study about the radiological aspect of this new hepatocellular adenoma subgroup. This highlights a strong correlation between MRI and histological analysis, with a specific pattern emerging for diagnosis. KEY POINTS: • Sonic hedgehog hepatocellular adenoma is a new hepatocellular adenoma subgroup associated with high risk of hemorrhage, but imaging features of this subgroup remain unknown. • Analysis of MR images and correlation with pathology revealed intralesional fluid-filled cavities and necrotic-hemorrhagic changes. • Intralesional fluid-filled cavities have not yet been described in other adenoma subtypes and represent a new MRI finding for sonic hedgehog hepatocellular adenoma.

The Crying Need for a Better Response Assessment in Rectal Cancer.

OPINION STATEMENT: Since total neoadjuvant treatment achieves almost 30% pathologic complete response, organ preservation has been increasingly debated for good responders after neoadjuvant treatment for patients diagnosed with rectal cancer. Two organ preservation strategies are available: a watch and wait strategy and a local excision strategy including patients with a near clinical complete response. A major issue is the selection of patients according to the initial tumor staging or the response assessment. Despite modern imaging improvement, identifying complete response remains challenging. A better selection could be possible by radiomics analyses, exploiting numerous image features to feed data characterization algorithms. The subsequent step is to include baseline and/or pre-therapeutic MRI, PET-CT, and CT radiomics added to the patients' clinicopathological data, inside machine learning (ML) prediction models, with predictive or prognostic purposes. These models could be further improved by the addition of new biomarkers such as circulating tumor biomarkers, molecular profiling, or pathological immune biomarkers.

Preoperative Predictors of Neoplasia in Patients Undergoing Small Bowel Resection for Complicated Crohn's Disease: A Multicentre Case-Control Study.

Crohn's disease (CD) is associated with an increased risk of small bowel neoplasia (SBN). We aimed to assess preoperative predictors of SBN in CD patients. We conducted a retrospective case-control study including CD patients who underwent surgery: cases were diagnosed with SBN on histopathological analysis and controls had no neoplasia. Preoperative cross-sectional imaging was reviewed by a panel of blinded expert radiologists. Fifty cases were matched to one hundred and fifty consecutive controls. In multivariable analysis, predictors of SBN were age ≥ 50 years (OR = 28, 95% CI = 5.05-206), median CD duration ≥ 17.5 years (OR = 4.25, 95% CI = 1.33-14.3), and surgery for stricture (OR = 5.84, 95% CI = 1.27-35.4). The predictors of small bowel adenocarcinoma were age ≥ 50 years (OR = 5.14, 95% CI = 2.12-12.7), CD duration ≥ 15 years (OR = 5.65, 95% CI = 2.33-14.3), and digestive wall thickening > 8 mm (OR = 3.79, 95% CI = 1.45-11.3). A predictive score based on the aforementioned factors was constructed. Almost 73.7% of patients with a high score had SBA. Old age, long small bowel CD duration, and stricture predicted the presence of SBN, particularly adenocarcinoma when patients have digestive wall thickening > 8 mm on preoperative imaging.

MRI restaging of rectal cancer: The RAC (Response-Anal canal-CRM) analysis joint consensus guidelines of the GRERCAR and GRECCAR groups.

PURPOSE: To develop guidelines by international experts to standardize data acquisition, image interpretation, and reporting in rectal cancer restaging with magnetic resonance imaging (MRI). MATERIALS AND METHODS: Evidence-based data and experts' opinions were combined using the RAND-UCLA Appropriateness Method to attain consensus guidelines. Experts provided recommendations for reporting template and protocol for data acquisition were collected; responses were analysed and classified as "RECOMMENDED" versus "NOT RECOMMENDED" (if ≥ 80% consensus among experts) or uncertain (if < 80% consensus among experts). RESULTS: Consensus regarding patient preparation, MRI sequences, staging and reporting was attained using the RAND-UCLA Appropriateness Method. A consensus was reached for each reporting template item among the experts. Tailored MRI protocol and standardized report were proposed. CONCLUSION: These consensus recommendations should be used as a guide for rectal cancer restaging with MRI.

Feasibility study of a Response Surveillance Program in locally advanced mid and low rectal cancer to increase organ preservation.

BACKGROUND: Assessment of tumor response in rectal cancer after neoadjuvant treatment by MRI (Tumour Regression Grade, TRG 1-5) is well standardized. The overall timing and method of defining complete response (cCR) remain controversial. The aim of this work was to evaluate the feasibility of a defined Response Surveillance Program (RSP) to increase organ preservation for locally advanced rectal cancer after neoadjuvant treatment. METHODS: A standardized program of clinical (CR), radiological (RR) and metabolic (MR) assessment of tumor response is defined over a 6 month period from completion of NACRT with formal assessment performed every 2 months (M). Patients with TRG1-3 at M2 and TRG1-2 at M4 continue in the program up to M6 assessment. Patients managed with this protocol from 2016 to 2020 were analyzed. The primary endpoint was rectal preservation rate. Secondary endpoints included disease-free survival and overall survival at 3 years. RESULT: 314 potentially suitable patients were enrolled in the RSP and 50 patients completed the six month program and were successfully enrolled into watch and wait. Fourteen (28%) were T2 tumor stage, 27 (54%) T3 and nine (18%) were T4. During watch and wait, patients with locoregional recurrence (n = 11) were treated with local excision (n = 3), endocavitary radiotherapy (n = 1), TME (n = 5) and APR (n = 2). With a median follow-up of 32 months, the rectal preservation rate was 88%, with a 3-year disease-free survival of 67% and an overall survival of 98%. CONCLUSION: This study validates the feasibility of the practical implementation of a Response Surveillance Program to increase organ preservation rates without compromising oncological outcomes in rectal cancer.

Structured and shared MRI staging lexicon and report of rectal cancer: A consensus proposal by the French Radiology Group (GRERCAR) and Surgical Group (GRECCAR) for rectal cancer.

PURPOSE: To develop French guidelines by experts to standardize data acquisition, image interpretation, and reporting in rectal cancer staging with magnetic resonance imaging (MRI). MATERIALS AND METHODS: Evidence-based data and opinions of experts of GRERCAR (Groupe de REcherche en Radiologie sur le CAncer du Rectum [i.e., Rectal Cancer Imaging Research Group]) and GRECCAR (Groupe de REcherche en Chirurgie sur le CAncer du Rectum [i.e., Rectal Cancer Surgery Research Group]) were combined using the RAND-UCLA Appropriateness Method to attain consensus guidelines. Experts scoring of reporting template and protocol for data acquisition were collected; responses were analyzed and classified as "Recommended" versus "Not recommended" (when ≥ 80% consensus among experts) or uncertain (when < 80% consensus among experts). RESULTS: Consensus regarding patient preparation, MRI sequences, staging and reporting was attained using the RAND-UCLA Appropriateness Method. A consensus was reached for each reporting template item among the experts. Tailored MRI protocol and standardized report were proposed. CONCLUSION: These consensus recommendations should be used as a guide for rectal cancer staging with MRI.

Hepatocellular Adenoma Risk Factors of Hemorrhage: Size Is Not the Only Concern!: Single-center Retrospective Experience of 261 Patients.

OBJECTIVE: Our aim was to determine independent risk factors of clinical bleeding of hepatocellular adenoma (HCA) to define a better management strategy. SUMMARY BACKGROUND DATA: HCA is a rare benign liver tumor with severe complications: malignant transformation that is rare (5%-8%) and more often, hemorrhage (20%-27%). To date, only size > 5 cm and histological subtype (possibly sonic hedgehog) are associated with bleeding, but these criteria are not clearly established. METHODS: We retrospectively collected data from a cohort of 268 patients with HCA managed in our tertiary center, from 1984 to 2020 and focused on clinical bleeding. Hemorrhage was considered severe when it required intensive care and moderate when bleeding symptoms required a hospitalization. We included 261 patients, of whom 130 (49.8%) had multiple HCAs or liver adenomatosis. All surgical specimen and liver biopsy were reviewed by an experienced liver pathologist and reclassified in the light of the current immunohistochemistry. Mean duration of follow-up was 93.3 months (range 1-363). We analyzed type, frequency, consequences of bleeding, and risk factors among clinical data and HCA characteristics. RESULTS: Eighty-three HCA (31.8%) were hemorrhagic. There were 4 pregnant women with 1 newborn death. One patient died before treatment. Surgery was performed in 78 (94.0%) patients. Mortality was nil and severe complications occurred in 11.5%. Multivariate analysis identified size (OR 1.02 [1.01-1.02], P < 0.001), shHCA (OR 21.02 [5.05-87.52], P < 0.001), b-catenin mutation on exon 7/8 (OR 6.47 [1.78-23.55], P = 0.0046), chronic alcohol consumption (OR 9.16 [2.47-34.01], P < 0.001) as independent risk factors of clinical bleeding. CONCLUSIONS: This series, focused on the hemorrhagic risk of HCA, shows that size, but rather more molecular subtype is determinant in the natural history of HCA.

ASS1 Overexpression: A Hallmark of Sonic Hedgehog Hepatocellular Adenomas; Recommendations for Clinical Practice.

Until recently, 10% of hepatocellular adenomas (HCAs) remained unclassified (UHCA). Among the UHCAs, the sonic hedgehog HCA (shHCA) was defined by focal deletions that fuse the promoter of Inhibin beta E chain with GLI1. Prostaglandin D2 synthase was proposed as immunomarker. In parallel, our previous work using proteomic analysis showed that most UHCAs constitute a homogeneous subtype associated with overexpression of argininosuccinate synthase (ASS1). To clarify the use of ASS1 in the HCA classification and avoid misinterpretations of the immunohistochemical staining, the aims of this work were to study (1) the link between shHCA and ASS1 overexpression and (2) the clinical relevance of ASS1 overexpression for diagnosis. Molecular, proteomic, and immunohistochemical analyses were performed in UHCA cases of the Bordeaux series. The clinico-pathological features, including ASS1 immunohistochemical labeling, were analyzed on a large international series of 67 cases. ASS1 overexpression and the shHCA subgroup were superimposed in 15 cases studied by molecular analysis, establishing ASS1 overexpression as a hallmark of shHCA. Moreover, the ASS1 immunomarker was better than prostaglandin D2 synthase and only found positive in 7 of 22 shHCAs. Of the 67 UHCA cases, 58 (85.3%) overexpressed ASS1, four cases were ASS1 negative, and in five cases ASS1 was noncontributory. Proteomic analysis performed in the case of doubtful interpretation of ASS1 overexpression, especially on biopsies, can be a support to interpret such cases. ASS1 overexpression is a specific hallmark of shHCA known to be at high risk of bleeding. Therefore, ASS1 is an additional tool for HCA classification and clinical diagnosis.

Organ preservation with chemoradiotherapy plus local excision for rectal cancer: 5-year results of the GRECCAR 2 randomised trial.

BACKGROUND: GRECCAR 2 was the first multicentre, randomised trial to compare local excision with total mesorectal excision in downstaged low rectal cancer. Encouraging oncological results were noted at 3 years' follow-up but needed to be corroborated with longer follow-up. In this study, we aimed to report the 5-year oncological outcomes, including local recurrence, metastatic disease, and survival. METHODS: Patients age 18 years and older with T2T3 low rectal cancer, of maximum size 4 cm, who were clinically good responders after chemoradiotherapy (residual tumour ≤2 cm) were randomly assigned before surgery to either local excision or total mesorectal excision. Randomisation was centralised and not stratified and used permuted blocks of size eight. In the local excision group, a completion total mesorectal excision was performed if pathological tumour stage was ypT2-3. The primary objective of this study was to assess the 5-year oncological outcomes of local recurrence, metastatic disease, disease-free survival, overall survival, and cancer-specific mortality, which were the secondary endpoints of GRECCAR 2. We used Kaplan-Meier estimates and Cox modelling to estimate and compare recurrence and survival in modified intention-to-treat and as-treated populations. This trial was registered with ClinicalTrials.gov, number NCT00427375. FINDINGS: Between March 1, 2007, and Sept 24, 2012, 148 patients who were good clinical responders were randomly assigned to treatment, three patients were excluded after randomisation (because they had metastatic disease, tumour >8 cm from anal verge, or withdrew consent), leaving 145 for analysis: 74 in the local excision group and 71 in the total mesorectal excision group. Median follow-up was 60 months (IQR 58-60) in the local excision group and 60 months (57-60) in the total mesorectal excision group. 23 patients died and five were lost to follow-up. In the local excision group, 26 had a completion total mesorectal excision for ypT2-3 tumour. In the modified intention-to-treat analysis, there was no difference between the local excision and total mesorectal excision groups in 5-year local recurrence (7% [95% CI 3-16] vs 7% [3-16]; adjusted hazard ratio [HR] 0·71 [95% CI 0·19-2·58]; p=0·60), metastatic disease (18% [CI 11-30] vs 19% [11-31]; 0·86 [0·36-2·06]; p=0·73), overall survival (84% [73-91] vs 82% [71-90]; 0·92 [0·38-2·22]; p=0·85), disease-free survival (70% [58-79] vs 72% [60-82]; 0·87 [0·44-1·72]; p=0·68), or cancer-specific mortality (7% [3-17] vs 10% [5-20]; 0·65 [0·17-2·49]; p=0·53). INTERPRETATION: The 5-year results of this multicentre randomised trial corroborate the 3-year results, providing no evidence of difference in oncological outcomes between local excision and total mesorectal excision. Local excision can be proposed in selected patients having a small T2T3 low rectal cancer with a good clinical response after chemoradiotherapy. FUNDING: National Cancer Institute of France.

Liver contrast-enhanced sonography: computer-assisted differentiation between focal nodular hyperplasia and inflammatory hepatocellular adenoma by reference to microbubble transport patterns.

OBJECTIVE: A new computer tool is proposed to distinguish between focal nodular hyperplasia (FNH) and an inflammatory hepatocellular adenoma (I-HCA) using contrast-enhanced ultrasound (CEUS). The new method was compared with the usual qualitative analysis. METHODS: The proposed tool embeds an "optical flow" algorithm, designed to mimic the human visual perception of object transport in image series, to quantitatively analyse apparent microbubble transport parameters visible on CEUS. Qualitative (visual) and quantitative (computer-assisted) CEUS data were compared in a cohort of adult patients with either FNH or I-HCA based on pathological and radiological results. For quantitative analysis, several computer-assisted classification models were tested and subjected to cross-validation. The accuracies, area under the receiver-operating characteristic curve (AUROC), sensitivity and specificity, positive predictive values (PPVs), negative predictive values (NPVs), false predictive rate (FPRs) and false negative rate (FNRs) were recorded. RESULTS: Forty-six patients with FNH (n = 29) or I-HCA (n = 17) with 47 tumours (one patient with 2 I-HCA) were analysed. The qualitative diagnostic parameters were accuracy = 93.6%, AUROC = 0.94, sensitivity = 94.4%, specificity = 93.1%, PPV = 89.5%, NPV = 96.4%, FPR = 6.9% and FNR = 5.6%. The quantitative diagnostic parameters were accuracy = 95.9%, AUROC = 0.97, sensitivity = 93.4%, specificity = 97.6%, PPV = 95.3%, NPV = 96.7%, FPR = 2.4% and FNR = 6.6%. CONCLUSIONS: Microbubble transport patterns evident on CEUS are valuable diagnostic indicators. Machine-learning algorithms analysing such data facilitate the diagnosis of FNH and I-HCA tumours. KEY POINTS: • Distinguishing between focal nodular hyperplasia and an inflammatory hepatocellular adenoma using dynamic contrast-enhanced ultrasound is sometimes difficult. • Microbubble transport patterns evident on contrast-enhanced sonography are valuable diagnostic indicators. • Machine-learning algorithms analysing microbubble transport patterns facilitate the diagnosis of FNH and I-HCA.

Unclassified hepatocellular adenoma expressing ASS1 associated with inflammatory hepatocellular adenomas.

Three liver nodules were fortuitously discovered in a 30-year-old obese woman during a gynecological workup and resected. Two nodules (6 and 1.5 cm) with histological characteristics of inflammatory hepatocellular adenoma (HCA) were C reactive protein positive with normal expression of glutamine synthetase. The third 6 cm nodule had all the characteristics of an Unclassified HCA with an overexpression of Argininosuccinate Synthase 1 (ASS1) in the tumor compared to the non-tumoral liver. The non-tumoral liver was highly steatotic. Upon MRI review, two HCAs were identified as inflammatory HCAs based on specific criteria. The third HCA was different from the other two with the presence of peculiar intratumoral fluid cavities. This first report on the association between unclassified HCA expressing ASS1 and inflammatory HCA reinforces the concept that common factors are implicated in HCA subtypes genesis. ASS1 is an interesting immuno-marker to identify among unclassified HCA a subgroup with a high risk of bleeding. ASS1 overexpression decreases sharply the number of "true" unclassified HCA.

Repeat surgery in HNF1alpha-inactivated adenomatosis.

BACKGROUND AND AIMS: Stopping oral contraceptives following nodule detection usually prevents further hepatocellular growth (HCA); rare cases of growth have been reported after surgery. The aim of the study was to review our resected HCA cases and their outcomes and more specifically, growth. METHODS: We retrieved all HCA cases that required a second intervention and HCA growth cases of none resected HCA after resection of one or several HCAs. RESULTS: Out of the 210 resected classified HCA cases, a second resection was performed in 5 cases, 4 of which were in women with HNF1alpha-inactivated adenomatosis (H-adenomatosis) and had a favorable outcome. The fifth case was the occurrence of an inflammatory HCA, 3 years after resection of a previous one. Of the 65 resected HNF1-inactivated HCAs (H-HCAs), the nodules that remained continued to increase very slowly in 3 adenomatosis cases. After surgery, the liver became dysmorphic years later in one case, and the nodules grew but not significantly in another case. After the diagnosis of adenomatosis, progressive growth leads to surgery 12 years later in the last case. CONCLUSION: These results confirm that, in rare H-adenomatosis, size of nodules may increase very slowly, probably in part through coalescence of micro H-HCAs and leading occasionally to a second resection.

Snapshot summary of diagnosis and management of hepatocellular adenoma subtypes.

Hepatocellular adenomas (HCA) are rare benign hepatocellular tumors occurring mainly in women taking oral contraceptives with 2 major complications: severe bleeding and malignant transformation that can be avoided if nodules exceeding 5 cm are resected. This simple attitude has been challenged in the recent years with HCA in men, in young adolescent, in aged persons, and complications in hepatocellular adenomas below 5 cm. The discovery of specific mutations leading to specific phenotypes has modified the clinical spectrum of the disease. The phenotypic immune classification of HCA based on the molecular classification is being widely used in liver referral centers. The aim of this snapshot is to briefly present for each subtype the clinical, pathological, immuno-pathological criteria as well as the risk of complications and guidelines for treatment and management.

New MRI features improve subtype classification of hepatocellular adenoma.

OBJECTIVE: MRI is crucial for the classification of hepatocellular adenomas (HCA) into subtypes. Our objective was to review and increase MRI criteria for subtype classification and define the limits. METHODS: Pathological and radiological data of 116 HCAs were retrospectively analyzed to investigate MRI features of HCA pathological subtypes. Risk for complication was also evaluated with regard to subtype and tumor size. RESULTS: 38/43 (88%) HNF1α-mutated HCAs (H-HCAs) were discriminated by (i) fatty component (homogeneous or heterogeneous) and (ii) hypovascular pattern, with a sensitivity of 88% and a specificity of 97%. 51/58 (88%) inflammatory HCAs (IHCAs) displayed features of sinusoidal dilatation (SD) including three different patterns (global SD, atoll sign, and a new "crescent sign" corresponding to a partial peripheral rim, hyperintense on T2W and/or arterial phase with persistent delayed enhancement). Sensitivity was 88% and specificity 100%. However, some HCA remained unclassifiable by MRI: HCA remodeled by necrotic/hemorrhagic changes covering > 50% of the lesion, H-HCAs without steatosis, IHCAs without SD, ß-catenin-mutated and unclassified HCAs. Regarding malignant transformation (5/116) and bleeding (24/116), none was observed when the HCA diameter was smaller than 5.2 cm and 4.2 cm, respectively. CONCLUSION: Based on the largest series evaluated until now, we identified several non-described MRI features and propose new highly sensitive and specific MRI criteria. With the addition of these new features, 88% of the two main HCA subtypes could be identified. KEY POINTS: • HNF1α-mutated hepatocellular adenomas (H-HCA) are characterized by the presence of fat and hypovascular pattern in MRI. • Inflammatory hepatocellular adenomas (I-HCA) are characterized by different patterns translating sinusoidal dilatation including the newly described crescent sign. • No MRI specific pattern was identified for ß-catenin-mutated HCA (b-HCA).

Unexpected discovery of small HNF1α-inactivated hepatocellular adenoma in pathological specimens from patients resected for liver tumours.

BACKGROUND AND AIMS: It is rare but not uncommon to discover micro/small HNF1α-inactivated hepatocellular adenoma (H-HCA) outside the context of resected H-HCA. We aimed to review our cases of micro/small H-HCA discovered by chance on different kinds of liver resected specimens. METHODS: We retrieved cases of micro/small H-HCA discovered by chance on resected specimens outside the context of H-HCA. All these nodules were liver fatty acid binding protein (LFABP)-negative contrasting with normal positivity in the surrounding non-tumoural liver, ruling out the possibility of focal steatosis or other subtypes of micro-HCAs. RESULTS: We identified 19 micro/small H-HCA cases. In 16 cases they were discovered in patients who underwent surgery for benign nodules including one haemangioma, six focal nodular hyperplasia, seven inflammatory HCA (including one with b-catenin activation), one HCA, whose subtype could not be identified because of massive necrosis/hemorrhage, and one hepatocellular carcinoma. In two additional cases, patients followed up for a melanoma underwent liver surgery to remove micro nodules possibly related to a metastatic process. Finally in one case a micro nodule was seen and resected during a cholecystectomy. CONCLUSION: Taken together, H-HCAs are more frequent than we initially supposed as micro and small HCAs cannot all be detected by routine ultrasound. Despite no information on the potential growth of these micro/small H-HCAs, there is no argument to stop oral contraceptives or to ask for a specific regular surveillance. The association of different subtypes of HCAs with focal nodular hyperplasia suggests they share or have common etiological factors.

Magnetic resonance texture parameters are associated with ablation efficiency in MR-guided high-intensity focussed ultrasound treatment of uterine fibroids.

OBJECTIVES: The objective of this study is to assess the association between texture parameter analysis derived from T2-weighted images and efficiency of magnetic resonance-guided focussed ultrasound (MRgFUS) ablation for the treatment of uterine fibroids. MATERIALS AND METHODS: Fifty-five women treated by MRgFUS were included in this retrospective analysis. Texture parameters were calculated using three 2D regions of interest placed on three consecutive slices on the same sagittal 3D T2-weighted images obtained at the beginning of MRgFUS ablation. Using uni- and multi-variate linear regression, texture parameters, fibroids/muscular T2W ratio (T2Wr), Funaki type, and fibroid depth were correlated with ablation efficiency, defined as the ratio of non-perfused volume (NPV) on post-treatment contrast-enhanced MRI by total volume of treatment-cell sizes used. Inter-rater reproducibility for texture analysis was assessed using variation coefficients. RESULTS: The mean total treatment cell volume was 49.5 (±30) ml, corresponding to a mean NPV of 57.2 (±57) ml (28%). The mean ablation efficiency was 1.14 (±0.7), with a range of 0.03-3.6. In addition to fibroid/muscular T2Wr, seven of the 14 texture parameters were significantly correlated with ablation efficiency: mean signal intensity (p = .047); Skewness (p = .03); Kurtosis (p = .015); mean uniformity (p = .052); mean sum of square (p = .045); mean sum entropy (p = .021) and mean entropy (p = .051). In multivariate linear regression, fibroid/muscular T2Wr and sum of entropy were associated with ablation efficiency. The inter-rater coefficient of variation for sum entropy was 2.6%. CONCLUSIONS: Uterine fibroid texture parameters provide complementary information to T2Wr, and are associated with MRgFUS efficiency. Key points Mean sum entropy is negatively correlated with MRgFUS efficiency (ρ = -0.307, p = .021). Fibroids/muscular T2-weighted ratio and entropy are associated with MRgFUS efficiency. Texture parameters are better predictors of MRgFUS efficiency than Funaki type. Fibroid MR texture analysis can improve patient selection for MRgFUS.

Transarterial chemoembolization for early stage hepatocellular carcinoma decrease local tumor control and overall survival compared to radiofrequency ablation.

BACKGROUND & AIMS: To compare treatment failure and survival associated with ultrasound-guided radiofrequency ablation (RFA) and trans-arterial chemoembolization (TACE) for early-stage HCC in Child-Pugh A cirrhosis patients. METHODS: 122 cirrhotic patients (RFA: 61; TACE: 61) were well matched according to cirrhosis severity; tumor size and serum alpha-fetoprotein. TACE was performed in case of inconspicuous nodule on US or nodule with "at risk location". Treatment failure was defined as local tumor progression (LTP) and primary treatment failure (failing to obtain complete response after two treatment session). Treatment failure and overall survival (OS) were compared after coarsened exact matching. Cox proportional model to assess independent predictive factors was performed. RESULTS: No significant difference was seen for baseline characteristics between the two groups. Mean tumor size was 3cm in both group with 41% HCC>3cm. Treatment failure rates after TACE was 42.6% (14 primary treatment failures and 12 LTP) and 9.8% after RFA (no primary treatment failure and 6 LTP) P < 0.001. TACE was the only predictive factor of treatment failure (Hazard ratio: 5.573). The 4-years OS after RFA and TACE were 54.1% and 31.5% (P = 0.042), respectively. CONCLUSION: For Child-Pugh A patients with early-stage HCC, alternative treatment as supra-selective TACE to RFA regarded as too challenging using common US guidance decrease significantly the local tumor control and overall survival. Efforts to improve feasibility of RFA especially for inconspicuous target have to be made.

Three-Dimensional Measurement of Hepatocellular Carcinoma Ablation Zones and Margins for Predicting Local Tumor Progression.

PURPOSE: To propose a postprocessing technique that measures tumor surface with insufficient ablative margins (≤ 5 mm) on magnetic resonance (MR) imaging to predict local tumor progression (LTP) following radiofrequency (RF) ablation. MATERIALS AND METHODS: A diagnostic method is proposed based on measurement of tumor surface with a margin ≤ 5 mm on MR imaging. The postprocessing technique includes fully automatic registration of pre- and post-RF ablation MR imaging, a semiautomatic segmentation of pre-RF ablation tumor and post-RF ablation volume, and a subsequent calculation of the three-dimensional exposed tumor surface area. The ability to use this surface margin ≤ 5 mm to predict local recurrence at 2 years was then tested on 16 patients with cirrhosis who were treated by RF ablation with a margin ≤ 5 mm in 2012: eight with LTP matched according to tumor size and number and α-fetoprotein level versus eight without local recurrence. RESULTS: The error of estimated tumor surface with a margin ≤ 5 mm was less than 12%. Results of a log-rank test showed that patients with a tumor surface area > 425 mm(2) had a 2-year LTP rate of 77.5%, compared with 25% for patients with a tumor surface area ≤ 425 mm(2) (P = .018). CONCLUSIONS: This proof-of-concept study proposes an accurate and reliable postprocessing technique to estimate tumor surface with insufficient ablative margins, and underscores the potential usefulness of tumor surface with a margin ≤ 5 mm to stratify patients with HCC treated by RF ablation according to their risk of LTP.