Contrast-enhanced ultrasound in the characterization of hepatocellular carcinomas treated by ablation: comparison with contrast-enhanced magnetic resonance imaging

Achievement of Complete Response and Drug-Free Status by Atezolizumab plus Bevacizumab Combined with or without Curative Conversion in Patients with Transarterial Chemoembolization-Unsuitable, Intermediate-Stage Hepatocellular Carcinoma: A Multicenter Proof-Of-Concept Study

Introduction

Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. When tumor shrinkage is obtained, achieving complete response (CR) is possible in many cases using curative conversion with resection, ablation, or superselective transarterial chemoembolization (TACE) with curative intent. This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter proof-of-concept study was conducted to show the value of curative conversion in immunotherapy-treated intermediate-stage HCC meeting TACE-unsuitable criteria.

Methods

This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. CR rate, drug-free rate, time to CR, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, progression-free survival (PFS), and overall survival (OS) were assessed in patients who achieved CR using resection, ablation, superselective TACE with curative intent following atezolizumab plus bevacizumab or atezolizumab plus bevacizumab alone.

Results

Clinical or pathological CR was achieved in 38 patients (35%) (median observation period: 21.2 months). The modalities of curative conversion in 35 patients were as follows: resection, 7; ablation, 13; and superselective TACE, 15. Three patients achieved clinical CR with atezolizumab plus bevacizumab therapy alone. Among the 38 CR patients, 25 achieved drug-free status. PFS was not reached, and 3 patients experienced recurrence after reaching CR. Regarding OS, there were no deaths in any of the CR patients. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved CR with atezolizumab plus bevacizumab followed by curative conversion, five achieved drug-free status.

Conclusion

The achievement of CR rate by curative conversion in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 23% of patients achieved drug-free status and no recurrence was observed from this patient subgroup with CR and drug-free status. Thus, achieving CR and/or drug-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread.

An alternative second performance of contrast-enhanced ultrasound for large focal liver lesion is necessary for sufficient characterization

Focal liver lesions (FFLs) evaluated using contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) may have the same or similar findings or substantial discrepant findings. Such phenomenon can be found in two performances of CEUS that the second performance of CEUS conducted shortly following the initial performance of CEUS. Discrepancy of two performances of CEUS for FFLs occurring in the same patient at a short internal has not been well addressed, which raises challenge for CEUS for the evaluation of FFLs. In this case study, such phenomenon is illustrated and implication is obtained.

Contrast-enhanced ultrasound (CEUS) in HCC diagnosis and assessment of tumor response to locoregional therapies

Hepatocellular carcinoma (HCC) is a global problem constituting the second leading cause of cancer deaths worldwide, thereby necessitating an accurate and cost-effective solution for managing care. Ultrasound is well poised to address this need due to its low cost, portability, safety, and excellent temporal resolution. The role of ultrasound for HCC screening has been well established and supported by multiple international guidelines. Similarly, contrast-enhanced ultrasound (CEUS) can be used for the characterization of focal liver lesions in high-risk populations, and standardized criteria for CEUS have been established by the American College of Radiology Liver Imaging Reporting & Data System (LI-RADS). Following HCC identification, CEUS can also be highly beneficial in treatment planning, delivery, and monitoring HCC response to locoregional therapies. Specific advantages of CEUS include providing real-time treatment guidance and improved diagnostic performance for the detection of residual tumor viability or recurrence, thereby identifying patients in need of retreatment substantially earlier than contrast-enhanced CT and MRI. This review provides a primer on ultrasound and CEUS for the screening and characterization of HCC, with an emphasis on assessing tumor response to locoregional therapies.

Surgery After Ultrasound-Guided Radiofrequency Ablation for Papillary Thyroid Carcinoma in 21 Patients: A Retrospective Study from a Single Center in China

BACKGROUND Radiofrequency ablation (RFA) is used to treat various cancers, but its use in thyroid cancer remains controversial. The aim of this study was to investigate surgical findings after RFA for papillary thyroid cancer (PTC). MATERIAL AND METHODS The study included 21 patients (average age 44.9±13.3 years) who had biopsy-confirmed thyroid cancer treated with RFA in multiple hospitals. Surgery was done in the First Hospital of China Medical University. RESULTS The 21 patients had a total of 32 thyroid nodules that were treated with RFA. Twenty-eight nodules were malignant, and 4 nodules were benign. Before RFA, 17 of the malignant nodules were >1 cm and 11 were ≤1 cm. Among the 28 malignant nodules, post-ablation lesions adhered to or invaded the structures surrounding the thyroid in 17 (60.7%), 19 (67.9%), and 22 (78.6%) nodules evaluated with ultrasound, contrast-enhanced computed tomography, and intraoperatively, respectively. Based on pathology results, 7 (33.3%) of the 21 patients had bilateral cancer. Ten (47.6%) of the 21 patients had central lymph node metastasis and 2 (9.5%) had lateral lymph node metastasis. For 5 (15.6%) of the 32 nodules, the fine-needle aspiration results were not consistent with the postoperative pathological results. Five (23.8%) of the 21 patients with lymph node metastasis had clinically negative (CN0) lesions. CONCLUSIONS RFA for PTC primary lesions may be incomplete and leave residual lymph node metastasis, even in lesions ≤1 cm. RFA should be recommended with caution in the treatment of operable patients with primary PTC.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Long-term efficacy of ultrasound-guided low power microwave ablation for the treatment of primary papillary thyroid microcarcinoma: a 3-year follow-up study

PURPOSE

To evaluate the safety and efficacy of ultrasound-guided low-power microwave ablation (MWA) for the treatment of papillary thyroid microcarcinoma (PTMC) with a 3-year follow-up.

METHODS

A total of 21 nodules diagnosed as PTMC from the 15 patients were performed with MWA at a power of 20 W. The images of the nodules were recorded by ultrasound before MWA and 1, 3, 6, 12 months after MWA, and every 6 months thereafter, respectively. The volumes of the nodules were compared before MWA and at each follow-up point after MWA. The volume reduction rate (VRR) of nodules was also calculated.

RESULTS

The mean volume of the nodules was 134.3 ± 129.8 mm³ initially (the range was 7.4-423.8 mm³), which decreased significantly to 2.3 ± 10.5 mm³ (the range was 0-48.1 mm³) of the ablation area (P = 0.000) at the follow-up point of 36 months with a mean VRR as 98.78 ± 5.61% (the range was 74.28-100%). During the follow-up period (the range was 36-48 months), 20 of the 21 nodules were completely absorbed and no recurrent nodule was found.

CONCLUSIONS

After a long-term follow-up of 3 years, the low power MWA showed a good safety and efficacy for the treatment of PTMC. In addition to surgery and active surveillance, MWA might be another alternative for patients with PTMC.

Development of a hybrid magnetic resonance and ultrasound imaging system

A system which allows magnetic resonance (MR) and ultrasound (US) image data to be acquired simultaneously has been developed. B-mode and Doppler US were performed inside the bore of a clinical 1.5 T MRI scanner using a clinical 1-4 MHz US transducer with an 8-metre cable. Susceptibility artefacts and RF noise were introduced into MR images by the US imaging system. RF noise was minimised by using aluminium foil to shield the transducer. A study of MR and B-mode US image signal-to-noise ratio (SNR) as a function of transducer-phantom separation was performed using a gel phantom. This revealed that a 4 cm separation between the phantom surface and the transducer was sufficient to minimise the effect of the susceptibility artefact in MR images. MR-US imaging was demonstrated in vivo with the aid of a 2 mm VeroWhite 3D-printed spherical target placed over the thigh muscle of a rat. The target allowed single-point registration of MR and US images in the axial plane to be performed. The system was subsequently demonstrated as a tool for the targeting and visualisation of high intensity focused ultrasound exposure in the rat thigh muscle.