Imaging standardisation in metastatic colorectal cancer: A joint EORTC-ESOI-ESGAR expert consensus recommendation.

BACKGROUND: Treatment monitoring in metastatic colorectal cancer (mCRC) relies on imaging to evaluate the tumour burden. Response Evaluation Criteria in Solid Tumors provide a framework on reporting and interpretation of imaging findings yet offer no guidance on a standardised imaging protocol tailored to patients with mCRC. Imaging protocol heterogeneity remains a challenge for the reproducibility of conventional imaging end-points and is an obstacle for research on novel imaging end-points. PATIENTS AND METHODS: Acknowledging the recently highlighted potential of radiomics and artificial intelligence tools as decision support for patient care in mCRC, a multidisciplinary, international and expert panel of imaging specialists was formed to find consensus on mCRC imaging protocols using the Delphi method. RESULTS: Under the guidance of the European Organisation for Research and Treatment of Cancer (EORTC) Imaging and Gastrointestinal Tract Cancer Groups, the European Society of Oncologic Imaging (ESOI) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), the EORTC-ESOI-ESGAR core imaging protocol was identified. CONCLUSION: This consensus protocol attempts to promote standardisation and to diminish variations in patient preparation, scan acquisition and scan reconstruction. We anticipate that this standardisation will increase reproducibility of radiomics and artificial intelligence studies and serve as a catalyst for future research on imaging end-points. For ongoing and future mCRC trials, we encourage principal investigators to support the dissemination of these imaging standards across recruiting centres.

A Novel Concept of a Phased-Array HIFU Transducer Optimized for MR-Guided Hepatic Ablation: Embodiment and First In-Vivo Studies.

Purpose: High-intensity focused ultrasound (HIFU) is challenging in the liver due to the respiratory motion and risks of near-/far-field burns, particularly on the ribs. We implemented a novel design of a HIFU phased-array transducer, dedicated to transcostal hepatic thermo-ablation. Due to its large acoustic window and strong focusing, the transducer should perform safely for this application. Material and Methods: The new HIFU transducer is composed of 256 elements distributed on 5 concentric segments of a specific radius (either 100, 111, or 125 mm). It has been optimally shaped to fit the abdominal wall. The shape and size of the acoustic elements were optimized for the largest emitting surface and the lowest symmetry. Calibration tests have been conducted on tissue-mimicking gels under 3-T magnetic resonance (MR) guidance. In-vivo MR-guided HIFU treatment was conducted in two pigs, aiming to create thermal ablation deep in the liver without significant side effects. Imaging follow-up was performed at D0 and D7. Sacrifice and post-mortem macroscopic examination occurred at D7, with the ablated tissue being fixed for pathology. Results: The device showed -3-dB focusing capacities in a volume of 27 × 46 × 50 mm3 as compared with the numerical simulation volume of 18 × 48 × 60 mm3. The shape of the focal area was in millimeter-range agreement with the numerical simulations. No interference was detected between the HIFU sonication and the MR acquisition. In vivo, the temperature elevation in perivascular liver parenchyma reached 28°C above physiological temperature, within one breath-hold. The lesion was visible on Gd contrast-enhanced MRI sequences and post-mortem examination. The non-perfused volume was found in pig #1 and pig #2 of 8/11, 6/8, and 7/7 mm along the LR, AP, and HF directions, respectively. No rib burns or other near-field side effects were visually observed on post-mortem gross examination. High-resolution contrast-enhanced 3D MRI indicated a minor lesion on the sternum. Conclusion: The performance of this new HIFU transducer has been demonstrated in vitro and in vivo. The transducer meets the requirement to perform thermal lesions in deep tissues, without the need for rib-sparing means.

Reliability of extracellular contrast versus gadoxetic acid in assessing small liver lesions using liver imaging reporting and data system v.2018 and European association for the study of the liver criteria.

BACKGROUND & AIMS: The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v.2018 and European Association for the Study of the Liver (EASL) criteria for the diagnosis of HCC have been widely evaluated, but their reliability should be investigated. We aimed to assess and compare the reliability of LI-RADS v.2018 and EASL criteria for the diagnosis of HCC using MRI with extracellular contrast agents (ECAs) and gadoxetic acid (GA) and determine the effect of ancillary features on LI-RADS reliability. APPROACH & RESULTS: Ten readers reviewed MRI studies of 92 focal liver lesions measuring <3 cm acquired with ECAs and GA <1 month apart from two prospective trials, assessing EASL criteria, LI-RADS major and ancillary features, and LI-RADS categorization with and without including ancillary features. Inter-reader agreement for definite HCC diagnosis was substantial and similar for the two contrasts for both EASL and LI-RADS criteria. For ECA-MRI and GA-MRI, respectively, inter-reader agreement was k = 0.72 (95% CI, 0.63-0.81) and k = 0.72 (95% CI, 0.63-0.80); for nonrim hyperenhancement, k = 0.63 (95% CI, 0.54-0.72) and k = 0.57 (95% CI, 0.48-0.66); and for nonperipheral washout, k = 0.49 (95% CI, 0.40-0.59) and k = 0.48 (95% CI, 0.37-0.58) for enhancing capsule. The inter-reader agreement for LI-RADS after applying ancillary features remained in the same range of agreement. CONCLUSIONS: Agreement for definite HCC was substantial and similar for both scoring systems and the two contrast agents in small focal liver lesions. Agreement for LI-RADS categorization was lower for both contrast agents, and including LI-RADS ancillary features did not improve agreement.

Contrast-enhanced CT and liver surface nodularity for the diagnosis of porto-sinusoidal vascular disorder: A case-control study.

BACKGROUND AND AIMS: Porto-sinusoidal vascular disorder (PSVD) is a rare and commonly overlooked cause of portal hypertension. The interest of CT analysis, including quantification of liver surface nodularity (LSN) for PSVD diagnosis has not been established. This study aimed at assessing the performance of LSN and CT features for a PSVD diagnosis in patients with signs of portal hypertension. APPROACH AND RESULTS: This retrospective case-control study included a learning cohort consisting of 50 patients with histologically proven PSVD, according to VALDIG criteria, and 100 control patients with histologically proven cirrhosis, matched on ascites. All patients and controls had at least one sign of portal hypertension and CT available within 1 year of liver biopsy. Principal component analysis of CT features separated patients with PSVD from patients with cirrhosis. Patients with PSVD had lower median LSN than those with cirrhosis (2.4 vs. 3.1, p < 0.001). Multivariate analysis identified LSN < 2.5 and normal-sized or enlarged segment IV as independently associated with PSVD. Combination of these two features had a specificity of 90% for PSVD and a diagnostic accuracy of 84%. Even better results were obtained in an independent multicenter validation cohort including 53 patients with PSVD and 106 control patients with cirrhosis (specificity 94%, diagnostic accuracy 87%). CONCLUSIONS: This study that included a total of 103 patients with PSVD and 206 patients with cirrhosis demonstrates that LSN < 2.5 combined with normal-sized or enlarged segment IV strongly suggests PSVD in patients with signs of portal hypertension.

[Update on cystic echinococcosis of the liver]. / Actualités sur l'échinococcose kystique hépatique.

Hepatic cystic echinococcosis (HCE), is a cosmopolitan parasitic zoonosis. Autochtonous HCE cases are rare and the majority of cases are imported from endemic areas. It induces the development in the liver of Echinococcus granulosus larvae. Extrahepatic localizations are also possible. Cyst development is slow with an often-late diagnosis. In Switzerland, HCE discovery is usually fortuitous, during an abdominal radiological examination. More rarely, an acute clinical picture reveals a complication that can be severe or even fatal. The diagnosis is based on ultrasound findings that allows cyst characterization according to the WHO classification. This guides the therapeutic choice: simple monitoring, albendazole therapy, percutaneous procedures or surgery.

L'échinococcose kystique hépatique (EKH) est une zoonose parasitaire cosmopolite. Les cas d'EKH autochtones sont rares et la majorité est importée par des patients originaires de zones d'endémie. L'EKH est due au développement dans le foie de la larve d'Echinococcus granulosus. Des localisations extrahépatiques sont également possibles. Son évolution est lente avec un diagnostic fréquemment tardif. En Suisse, celui-ci est souvent fortuit, à l'occasion d'un examen radiologique abdominal. Plus rarement, un tableau clinique aigu et bruyant révèle une complication qui peut être sévère, voire mortelle. Le diagnostic basé sur l'échographie permet la caractérisation du kyste selon la classification de l'OMS. Celle-ci guide le choix thérapeutique: surveillance simple, traitement par albendazole, gestes percutanés ou chirurgie.

Magnetic resonance imaging-guided lumbar nerve root infiltrations: optimization of an in-house protocol.

BACKGROUND: For the treatment of radicular pain, nerve root infiltrations can be performed under MRI guidance in select, typically younger, patients where repeated CT exams are not desirable due to associated radiation risk, or potential allergic reactions to iodinated contrast medium. METHODS: Fifteen 3 T MRI-guided nerve root infiltrations were performed in 12 patients with a dedicated surface coil combined with the standard spine coil, using a breathhold PD sequence. The needle artifact on the MR images and the distance between the needle tip and the infiltrated nerve root were measured. RESULTS: The distance between the needle tip and the nerve root was 2.1 ± 1.4 mm. The visual artifact width, perpendicular to the needle long axis, was 2.1 ± 0.7 mm. No adverse events were reported. CONCLUSION: This technical note describes the optimization of the procedure in a 3 T magnetic field, including reported procedure time and an assessment of targeting precision.

The diagnostic performance of a simulated "short" gadoxetic acid-enhanced MRI protocol is similar to that of a conventional protocol for the detection of colorectal liver metastases.

OBJECTIVES: To compare the performance of standard and simulated short gadoxetic acid-enhanced MRI protocols for the detection of colorectal liver metastases (CRLM). METHODS: From 2008 to 2017, 67 patients (44 men (66%); mean age 65 ± 11 years old) who underwent gadoxetic acid-enhanced MRI during the initial work-up for colorectal cancer were included. Exams were independently reviewed by two readers blinded to clinical data in two reading sessions: (1) all acquired sequences (standard "long" protocol) and (2) only T2-weighted, diffusion-weighted, and hepatobiliary phase images (simulated "short" protocol). Readers characterized detected lesions using a 5-point scale (1-certainly benign to 5-certainly malignant). A lesion was considered a CRLM when the score was ≥ 3. The reference standard was histopathology or 12-month imaging follow-up. Chi-square, Student's t, and McNemar tests were used for comparisons. RESULTS: A total of 486 lesions including 331 metastases (68%) were analyzed. The metastasis detection rate was 86.1% (95% CI 82-89.4)-86.7% (82.6-90) and 85.8% (81.6-89.2)-87% (82.9-90.2) with the short and long protocols, respectively (p > 0.99). Among detected lesions, 92.1% (89.1-94.4)-94.8% (92.2-96.6) and 84.6% (80.8-87.7)-88.8% (85.4-91.5) were correctly classified with the short and long protocols, respectively (p = 0.13 and p = 0.10). The results remained unchanged when lesions scored ≥ 4 were considered as CRLM. CONCLUSION: The diagnostic performance of a simulated short gadoxetic enhanced-MR protocol including T2-weighted, diffusion-weighted, and hepatobiliary phase appears similar to that of a standard long protocol including dynamic phase images. Since this protocol shortens the duration of MR examination, it could facilitate the evaluation of patients with colorectal liver metastases. KEY POINTS: • The detection rate of colorectal metastases with a simulated, short, MRI protocol was similar to that of a standard protocol. • The performance of both protocols for the differentiation of metastases and benign lesions appears to be similar. • A short MR imaging protocol could facilitate the evaluation of patients with colorectal liver metastases.

A 13-Year-Old Male With Diagnosed Idiopathic Pulmonary Hypertension: Is it Really Idiopathic?

CASE PRESENTATION: A 13-year-old male was referred after incidental finding of cardiomegaly on chest radiograph and signs of pulmonary hypertension on subsequent cardiology consult. He was diagnosed with idiopathic pulmonary hypertension, and came to our center for a second opinion. He was born from consanguineous parents. He reported to be asymptomatic in his daily life. He was not on medications. Family history was not contributive.

Enhancement of HIFU thermal therapy in perfused tissue models using micron-sized FTAC-stabilized PFOB-core endovascular sonosensitizers.

BACKGROUND: High intensity focused ultrasound (HIFU) is clinically accepted for the treatment of solid tumors but remains challenging in highly perfused tissue due to the heat sink effect. Endovascular liquid-core sonosensitizers have been previously suggested to enhance the thermal energy deposition at the focal area and to lower the near-/far-field heating. We are investigating the therapeutic potential of PFOB-FTAC micro-droplets in a perfused tissue-mimicking model and postmortem excised organs. METHOD: A custom-made in vitro perfused tissue-mimicking model, freshly excised pig kidneys (n = 3) and liver (n = 1) were perfused and subjected to focused ultrasound generated by an MR-compatible HIFU transducer. PFOB-FTAC sonosensitizers were injected in the perfusion fluid up to 0.235% v/v ratio. Targeting and on-line PRFS thermometry were performed on a 3 T MR scanner. Assessment of the fluid perfusion was performed with pulsed color Doppler in vitro and with dynamic contrast-enhanced (DCE)-MRI in excised organs. RESULTS: Our in vitro model of perfused tissue demonstrated re-usability. Sonosensitizer concentration and perfusion rate were tunable in situ. Differential heating under equivalent HIFU sonications demonstrated a dramatic improvement in the thermal deposition due to the sonosensitizers activity. Typically, the energy deposition was multiplied by a factor between 2.5 and 3 in perfused organs after the administration of micro-droplets, while DCE-MRI indicated an effective perfusion. CONCLUSION: The current PFOB-FTAC micro-droplet sonosensitizers provided a large and sustained enhancement of the HIFU thermal deposition at the focal area, suggesting solutions for less technological constraints, lower risk for the near-/far- field heating. We also report a suitable experimental model for other MRgHIFU studies.

Liver transplantation for hepatocellular carcinoma after successful treatment of macrovascular invasion - a multi-center retrospective cohort study.

Macrovascular invasion is considered a contraindication to liver transplantation for hepatocellular carcinoma (HCC) due to a high risk of recurrence. The aim of the present multicenter study was to explore the outcome of HCC patients transplanted after a complete radiological regression of the vascular invasion by locoregional therapies and define sub-groups with better outcomes. Medical records of 45 patients were retrospectively reviewed, and imaging was centrally assessed by an expert liver radiologist. In the 30 patients with validated diagnosis of macrovascular invasion, overall survival was 60% at 5 years. Pretransplant alpha-fetoprotein (AFP) value was significantly different between patients with and without recurrence (P = 0.019), and the optimal AFP cutoff was 10ng/ml (area under curve = 0.78). Recurrence rate was 11% in patients with pretransplant AFP < 10ng/ml. The number of viable nodules (P = 0.008), the presence of residual HCC (P = 0.036), and satellite nodules (P = 0.001) on the explant were also significantly different between patients with and without recurrence. Selected HCC patients with radiological signs of vascular invasion could be considered for transplantation, provided that they previously underwent successful treatment of the macrovascular invasion resulting in a pretransplant AFP < 10 ng/ml. Their expected risk of post-transplant HCC recurrence is 11%, and further prospective validation is needed.

Mild hyperthermia by MR-guided focused ultrasound in an ex vivo model of osteolytic bone tumour: optimization of the spatio-temporal control of the delivered temperature.

BACKGROUND: Magnetic resonance guided focused ultrasound was suggested for the induction of deep localized hyperthermia adjuvant to radiation- or chemotherapy. In this study we are aiming to validate an experimental model for the induction of uniform temperature elevation in osteolytic bone tumours, using the natural acoustic window provided by the cortical breakthrough. MATERIALS AND METHODS: Experiments were conducted on ex vivo lamb shank by mimicking osteolytic bone tumours. The cortical breakthrough was exploited to induce hyperthermia inside the medullar cavity by delivering acoustic energy from a phased array HIFU transducer. MR thermometry data was acquired intra-operatory using the proton resonance frequency shift (PRFS) method. Active temperature control was achieved via a closed-loop predictive controller set at 6 °C above the baseline. Several beam geometries with respect to the cortical breakthrough were investigated. Numerical simulations were used to further explain the observed phenomena. Thermal safety of bone heating was assessed by cross-correlating MR thermometry data with the measurements from a fluoroptic temperature sensor inserted in the cortical bone. RESULTS: Numerical simulations and MR thermometry confirmed the feasibility of spatio-temporal uniform hyperthermia (± 0.5 °C) inside the medullar cavity using a fixed focal point sonication. This result was obtained by the combination of several factors: an optimal positioning of the focal spot in the plane of the cortical breakthrough, the direct absorption of the HIFU beam at the focal spot, the "acoustic oven effect" yielded by the beam interaction with the bone, and a predictive temperature controller. The fluoroptical sensor data revealed no heating risks for the bone and adjacent tissues and were in good agreement with the PRFS thermometry from measurable voxels adjacent to the periosteum. CONCLUSION: To our knowledge, this is the first study demonstrating the feasibility of MR-guided focused ultrasound hyperthermia inside the medullar cavity of bones affected by osteolytic tumours. Our results are considered a promising step for combining adjuvant mild hyperthermia to external beam radiation therapy for sustained pain relief in patients with symptomatic bone metastases.

Biliary Involvement in Type 2 Autoimmune Pancreatitis.

Autoimmune pancreatitis (AIP) is a rare condition classified in 2 subtypes. Their distinction relies on a combination of clinical, serological, morphological and histological features. Type 1 is a pancreatic manifestation of IgG4-related disease characterized by multiorgan infiltration by IgG4 plasmocytes. In this condition, hepatobiliary infiltration is frequent and often mimics cholangiocarcinoma or primary sclerosing cholangitis. On the other hand, type 2 is commonly limited to the pancreas. Herein, we describe the case of a patient who presented a type 2 AIP associated with cholangiopathy, a condition not described in the established criteria. He first developed a pancreatitis identified as type 2 by the typical histopathological features and lack of IgG4 in the serum and tissue. Despite a good clinical response to steroids, cholestasis persisted, identified by MR cholangiography as a stricture of the left hepatic duct with dilatation of the intrahepatic bile duct in segments 2 and 3. Biliary cytology was negative. Evolution was favorable but after steroid tapering a few months later, the patient suffered from recurrence of the pancreatitis as well as progression of biliary attempt, suspicious for cholangiocarcinoma. As the investigations again ruled out neoplastic infiltration or primary sclerosing cholangitis, azathioprine was initiated with resolution of both pancreatic and biliary attempts.

Self-Scanned HIFU Ablation of Moving Tissue Using Real-Time Hybrid US-MR Imaging.

OBJECTIVE: High intensity focused ultrasound (HIFU) treatment in the abdominal cavity is challenging due to the respiratory motion. In the self-scanning HIFU ablation method, the focal spot is kept static and the heating pattern is obtained through natural tissue motion. This paper describes a novel approach for modulating the HIFU power during self-scanning in order to compensate for the effect of tissue motion on thermal buildup. METHODS: The therapy, using hybrid ultrasound (US)/magnetic resonance (MR) imaging, consists of detecting and tracking speckle on US images in order to predict the next tissue position, and modulating the HIFU power according to the tissue speed in order to obtain a rectilinear pattern of uniform temperature elevation. Experiments were conducted on ex vivo tissue subjected to a breathing-like motion generated by an MR-compatible robot and sonicated by a phased array HIFU transducer. RESULTS: US and MR data were free from interferences. For both periodic and non-periodic motion, MR temperature maps showed a substantial improvement in the uniformity of the temperature elevation by using acoustic power modulation. CONCLUSION: The presented method does not require a learning stage and enables a duty cycle close to 100%, higher average acoustic intensity and avoidance of side lobe effects versus performing HIFU beam steering to compensate tissue motion. SIGNIFICANCE: To our knowledge, the proposed method provides the first experimental validation of the self-scanning HIFU ablation paradigm via a real-time hybrid MRI/US imaging, opening the path toward self-scanning in vivo therapies.

Endovascular Treatment of Arterial Complications After Liver Transplantation: Long-Term Follow-Up Evaluated on Doppler Ultrasound and Magnetic Resonance Cholangiopancreatography.

PURPOSE: To evaluate long-term arterial patency and abnormalities of bile ducts in patients that had endovascular treatment for arterial complications after liver transplantation (LT). MATERIALS AND METHODS: Between 2004 and 2014, 1048 LTs were consecutively performed in our institution and 53 patients (42 men; age range 19-69) were diagnosed and treated by endovascular techniques for arterial complications such as stenosis, thrombosis, dissection or kinking of the hepatic artery (HA). Radiological and surgical data were retrospectively analyzed, and survivors were contacted to undergo follow-up Doppler ultrasound (DUS) of the HA and magnetic resonance cholangiopancreatography. RESULTS: The primary technical success of endovascular treatment was 94% (n = 50). The patency rate of HA at 5-year was 81%. After a median follow-up of 58 months, 17 patients (32%) developed radiological features of ischemic cholangiopathy (IC), including 7 patients with abnormal DUS and 10 with normal DUS. Patients who presented with complications of the HA in the first 3 months after LT developed IC more frequently (42%) than others (12%) (p = 0.028). No other factor was associated with the development of IC. CONCLUSION: IC was more often observed when HA complication occurred within the first 3 months after LT. The presence of IC was not excluded by a normal DUS during follow-up.

Quantification of Liver Surface Nodularity at CT: Utility for Detection of Portal Hypertension.

Purpose To determine whether quantification of liver surface nodularity (LSN) provides an estimate of the presence of clinically significant portal hypertension (CSPH) in patients with cirrhosis. Materials and Methods This retrospective study included a training cohort (n = 189) and separate external validation cohort (n = 78), both composed of patients with cirrhosis who underwent abdominal CT and hepatic venous pressure gradient (HVPG) measurement between 2010 and 2016. The LSN score, liver and spleen volumes, liver-to-spleen volume ratio, platelet count to spleen diameter ratio, Iranmanesh score, aspartate amino transferase-to-platelet ratio index, and Fibrosis-4 index were derived from CT images and serum laboratories. The accuracy of the various tests for predicting CSPH was evaluated with area under the receiver operating characteristic curve (AUROC) and compared by using the DeLong test. Student t test and Pearson correlation coefficient were used. Results One hundred eighty-nine patients were analyzed (119 men [mean age ± standard deviation, 57 years ± 11; range, 29-81 years] and 70 women [mean age, 61 years ± 10; range, 34-83 years]; overall mean age, 58 years ± 10; range, 29-83 years). A total of 102 patients (54%) had CSPH. LSN score correlated with HVPG (r = 0.75; P < .001). Patients with CSPH had a higher LSN score than did those without CSPH (3.2 ± 0.6 vs 2.4 ± 0.3; P < .001). A cutoff value of 2.8 had a positive predictive value of 88% for CSPH; the AUROC of LSN was 0.88 ± 0.03. This was higher than that of other available noninvasive tests (DeLong, all P < .001). In the validation cohort, LSN score of 2.8 had a positive predictive value of 86% for CSPH; the AUROC was 0.87 ± 0.04. Conclusion The CT-based liver surface nodularity score demonstrated high diagnostic performance for detecting clinically significant portal hypertension and outperformed multiple other noninvasive tests. © RSNA, 2018 Online supplemental material is available for this article.

[Can the management and pronostic of pancreatic adenocarcinoma be improved ?] / Adénocarcinome du pancréas : peut-on améliorer la prise en charge et le pronostic ?

Pancreatic cancer is the 10th leading cause of death worldwide. It is a very lethal and aggressive tumor, with a 5-year overall survival rate under 5 % for confirmed ductal adenocarcinoma. Even though many genes have been identified as possible treatment targets, surgery remains the only curative treatment. Imaging is essential to the initial workup and is mostly based on CT-scan and MRI studies. Resectability is based on the absence of distant metastases and arterial vasculature infiltration. 3D imaging reconstruction could add precision to the surgical evaluation. Many phase II non randomized studies have shown that neo-adjuvant chemotherapy had a positive effect on pancreatic cancer. Nevertheless this approach is only reserved for cases with locally advanced tumors.

Le cancer du pancréas est la 10e cause de décès au monde. C'est une tumeur très agressive avec un taux de survie global à cinq ans en dessous de 5 % pour les adénocarcinomes canalaires confirmés. Bien que plusieurs gènes aient pu être identifiés comme d'éventuels cibles de traitements, la chirurgie reste l'unique traitement curatif pour cette maladie. Dans le bilan initial, l'imagerie tient une place prépondérante et est surtout basée sur le CT-scan et l'IRM. Les critères de résécabilité chirurgicale sont basés sur l'absence de métastases à distance et d'infiltration des vaisseaux artériels. La reconstruction 3D des images semble apporter plus de précision afin de déterminer la stratégie chirurgicale. Plusieurs études prospectives de phase II non randomisées ont déjà montré que les traitements néoadjuvants de chimiothérapie auraient un effet bénéfique sur les cancers du pancréas. Toutefois, cette approche est pour l'instant réservée uniquement aux cas localement avancés.

Ethylene vinyl alcohol copolymer for occlusion of specific portal branches during preoperative portal vein embolisation with n-butyl-cyanoacrylate.

OBJECTIVES: To evaluate the safety and efficacy of ethylene vinyl alcohol copolymer (EVOH) injection for selective occlusion of portal branches considered at risk for non-target embolisation during preoperative portal vein embolisation (PVE). METHODS: Twenty-nine patients (mean age, 57 ± 17 years) submitted to PVE with n-butyl-cyanoacrylate (NBCA) and additional EVOH for selected portal branches were retrospectively analysed. Indications for the use of EVOH and the selected portal branches were evaluated. Degree of hypertrophy of the future liver remnant (FLR) and kinetic growth were assessed by CT volumetry performed before and 3-6 weeks after PVE. Clinical outcome and histopathological analysis of portal veins occluded with EVOH were reviewed. RESULTS: EVOH was indicated intraoperatively for embolisation of selected portal branches that the operator reported at risk to provoke non-target embolisation with NBCA. Indications for the use of EVOH were embolisation of segment IV (n = 21), embolisation of segmental portal branches with early bifurcation (n = 7) and PVE in a 1-year-old girl with cystic hamartomas. All targeted portal branches were successfully embolised. There were no cases with non-target embolisation by EVOH. The degree of hypertrophy of the FLR was 14.3 ± 8.1% and the kinetic growth rate was 2.7 ± 1.8% per week. CONCLUSION: EVOH is safe and effective for embolisation of selected portal vein branches considered at risk for non-target embolisation. KEY POINTS: • EVOH is another effective liquid embolic agent for preoperative PVE. • EVOH is relatively simple to handle with a minimal risk of non-target embolisation. • During PVE, some portal branches considered complicated to occlude with NBCA may be efficiently embolised with EVOH.