Edward Leen

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria—A 10-Year Update

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes. Online supplemental material is available for this article .

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver – Update 2012

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Liver tumor characterization: Comparison between liver-specific gadoxetic acid disodium-enhanced MRI and biphasic CT - A multicenter trial

Objective: In our multi center trial we compared the potentials of biphasic contrast-enhanced computed tomography (CT) and a novel tissue-specific magnetic resonance imaging (MRI) contrast agent gadoxetic acid disodium in liver lesion characterization. Methods: A total of 176 patients with 252 liver lesions were analyzed. There were 104 malignant and 148 benign lesions. High-field strength (1.0 T or 1.5 T) MR systems with T1-and T2-weighted sequences were used with and without fat suppression. After gadoxetic acid disodium injection, dynamic imaging and hepatocyte phase MR imaging were performed. Biphasic with 150 mg I/kg of body weight (100-200 mL) spiral CT was also performed. Image reading consisted of on-site (by study investigators) and fully blinded off-site (by E.S.P; C.R; and A.S) evaluations. The classification (benign or malignant) and characterization (lesion type) outcomes of both techniques were assessed. All imaging results were verified against a standard of reference. Results: Both on-site and off-site evaluations demonstrated increases in the lesion classification accuracy with gadoxetic acid disodium-enhanced MRI when compared with spiral CT. This improvement was also shown for characterization. Gadoxetic acid disodium was well tolerated. Conclusions: Gadoxetic acid disodium offers a safe and diagnostically powerful tool for the evaluation of patients with focal liver lesions with a reliable assessment of lesion classification and characterization.

Potential Value of Contrast-Enhanced Intraoperative Ultrasonography During Partial Hepatectomy for Metastases: An Essential Investigation Before Resection?

Objective:The aim of the study was to assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in the hepatic staging of patients undergoing liver resection. Methods:Sixty patients scheduled to undergo liver resection for metastatic disease were studied. Preoperative staging with contrast-enhanced CT and/or MR scans was performed within 2 to 6 weeks of operation. Following exploration, intraoperative ultrasound (IOUS) was performed using an HDI-5000 scanner (Philips) and a finger-probe with pulse inversion harmonic (PIH) capability. CE-IOUS in the PIH mode was performed in a standardized protocol (low MI: 0.02–0.04) after intravenous injection of 3–4 mL of SonoVue (Bracco spa, Milan); all detected lesions on precontrast and postcontrast scans were counted and mapped. Any alteration in surgical management was documented following CE-IOUS compared with IOUS. Results:Three patients were excluded due to disseminated disease on exploration. CE-IOUS was significantly more sensitive than CT/MR and IOUS in detecting liver metastases (96.1% versus 76.7% and 81.5%, respectively) (P < 0.05); it altered surgical management in 29.8% (17 of 57) of cases, due to 1) additional metastases in 19.3% (11 of 57), 2) less metastases in 3.5% (2 of 57), 3) benign lesions wrongly diagnosed as metastasis on IOUS/CT in 5.3% (3 of 57), and 4) vascular proximity in 1.8% (1 of 57). Management was unchanged in 70.2% (40 of 57) despite additional lesions detected in 3.5% (2 of 57) and benign lesion wrongly diagnosed on IOUS and CT as metastasis in 1.8% (1 of 57). CE-IOUS altered combined IOUS/CT/MR staging in 35.1%. Conclusion:These preliminary results suggest CE-IOUS is an essential tool prior to liver resection for metastases.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update.

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

Multimodality Imaging of Neoplastic and Nonneoplastic Solid Lesions of the Pancreas

Solid lesions of the pancreas represent a heterogeneous group of entities that can be broadly classified as either neoplastic or nonneoplastic. Neoplastic lesions include pancreatic adenocarcinoma, pancreatic neuroendocrine tumor, solid pseudopapillary tumor, pancreatoblastoma, pancreatic lymphoma, metastases to the pancreas, and rare miscellaneous neoplasms. Nonneoplastic lesions include focal pancreatitis, fatty infiltration-replacement, intrapancreatic accessory spleen, congenital anomalies such as prominent pancreatic lobulation and bifid pancreatic tail (pancreatic bifidum), and rare miscellaneous lesions (eg, pancreatic sarcoidosis, Castleman disease of the pancreas). A variety of imaging modalities are available for assessing these solid lesions, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging, endoscopic US, and hybrid nuclear imaging techniques such as single photon emission computed tomography-CT and positron emission tomography-CT, each of which has its own strengths and limitations. Accurate diagnosis can be challenging, and use of a multimodality imaging approach is often helpful in equivocal or complex cases. Knowledge of relevant clinical information and key radiologic features is essential for confident lesion characterization and differentiation.

Quantification of Tumor Microvascularity with Respiratory Gated Contrast Enhanced Ultrasound for Monitoring Therapy

The aim of this feasibility study was to evaluate the response to cytotoxic and antiangiogenic treatment of colorectal liver metastasis using respiratory gated contrast enhanced ultrasonography. Seven patients were monitored with contrast enhanced ultrasound. Sulfur hexafluoride filled microbubbles (SonoVue; Bracco S.P.A., Milan, Italy) were used as contrast agent and the scans were performed with a nonlinear imaging technique (power modulation) at low transmit power (MI=0.06). The mean image intensity in the metastatic lesion and in the normal liver parenchyma were measured as a function of time and time-intensity curves from linearized image data were formed. A novel respiratory gating technique was utilized to minimize the effects of respiratory motion on the images. A reference position of the diaphragm (or other echogenic interface) was selected and all frames where the diaphragm deviated from that position were rejected. The wash-in time (start of enhancement to peak) of metastasis and adjacent normal liver parenchyma was measured from time-intensity curves. The ratio of wash-in time of the lesion to that of the normal parenchyma (WITR) was used to compare the perfusion rate. In a reproducibility study (five patients), the average deviation of WITR was found to be 9%. There was an increase in the WITR for patients responding to treatment (mean WITR increase of 17% after first dose of treatment and 75% at the end of the therapy). In four out of five patients (80%) responding to therapy WITR predicted their response from the first treatment. All six patients that responded to therapy by the end of the therapy cycle (6-9 doses) were correctly predicted by using WITR. The WITR may be a new surrogate marker indicative of early tumor response for colorectal cancer patients undergoing cytotoxic and antiangiogenic therapy. (E-mail: maverk@ucy.ac.cy).

Inflammation within Carotid Atherosclerotic Plaque: Assessment with Late-Phase Contrast-enhanced US

PURPOSE To determine if the number of nontargeted microbubbles retained in human carotid plaque is sufficient to be detected with ultrasonography (US). MATERIALS AND METHODS The study protocol was approved by the local research ethics committee. Informed consent was obtained. A total of 37 subjects with carotid atherosclerosis (mean age, 69.9 years; age range, 49-86 years), of whom 27 (73%) were men (mean age, 69.7 years; age range, 58-86 years) and 10 (27%) were women (mean age, 70.3 years; age range, 49-86 years), were studied between December 2008 and May 2009 with late-phase (LP) contrast material-enhanced US by using flash imaging with a nonlinear mode at an intermediate mechanical index of 0.34 6 minutes after bolus contrast agent injection. Plaques were defined as symptomatic if symptoms consistent with stroke, transient ischemic attack, or amaurosis fugax had occurred in the neurovascular territory of the plaque studied within 12 months prior to entry into the study. Plaques were defined as asymptomatic if no such events had ever occurred within the neurovascular territory. Raw linear data were used to quantify echogenicity of the plaque, which was normalized to lumen echogenicity. Gray-scale median score was also calculated. RESULTS Of the 37 subjects, 16 (43%) had symptomatic plaques and 21 (57%) had asymptomatic plaques. All examinations yielded evaluable LP contrast-enhanced US data. Normalized LP plaque echogenicity was greater in the symptomatic group (0.39; 95% confidence interval: -0.11, 0.89) than in the asymptomatic group (0.69; 95% confidence interval: -1.04, -0.34) (P = .0005). There was a moderate (rho = -0.44, P = .016) inverse correlation between normalized LP plaque echogenicity and gray-scale median score. CONCLUSION By quantifying microbubble retention within the carotid plaque, LP contrast-enhanced US depicts clear differences between groups of subjects with plaque ipsilateral to symptoms and asymptomatic plaques. This technique has promise as a tissue-specific marker of inflammation and a potential role in the risk stratification of atherosclerotic carotid stenosis.

The relationship between hypoalbuminaemia, tumour volume and the systemic inflammatory response in patients with colorectal liver metastases.

The relationship between hypoalbuminaemia, tumour volume and C-reactive protein was examined in patients with colorectal liver metastases (n=57). On multiple regression analysis, albumin concentrations were independently associated with C-reactive protein (r=0.56, P<0.001) but not percentage hepatic replacement (P=0.34). These results show that hypoalbuminaemia is associated with the presence of a systemic inflammatory response rather than tumour volume in patients with colorectal liver metastases.

Enhancement of liver parenchyma after injection of hepatocyte-specific MRI contrast media: a comparison of gadoxetic acid and gadobenate dimeglumine

To compare enhancement of liver parenchyma in MR imaging after injection of hepatocyte‐specific contrast media.