Radiofrequency ablation of liver cancers adjacent to the gallbladder without gallbladder isolation under contrast-enhanced ultrasound monitoring: a preliminary study

Interaction Between Microbubbles and Microwave Ablation: A Phantom and Rabbit Model

OBJECTIVES

This study aimed to explore the interactions between microbubbles and microwave ablation (MWA).

METHODS

The study employed custom-made phantoms (in vitro) and white New Zealand rabbits (in vivo). MWA was performed with or without microbubbles in the phantoms (2 × 105 particles mL-1) and rabbit livers (intravenous injection of 0.05 mL/kg SonoVue). During the MWA, K-type thermocouple probes were used to monitor the MWA-induced temperature increase. Contrast-enhanced ultrasound imaging (CEUS) was used to monitor and analyze the microbubbles signal intensity. After MWA, the ablation-zone volumes were evaluated and compared between the groups with and without microbubbles.

RESULTS

In both the phantom models and rabbits, microbubbles showed no significant influence on MWA, including the ablation range and MWA-induced temperature increase. In phantoms and rabbit livers filled with microbubbles, MWA caused the formation of a gradually expanding microbubble-defect region over the ablation time. An increase in the temperature caused microbubble destruction.

CONCLUSIONS

Microbubbles had no significant influence on MWA. However, MWA induced the destruction of microbubbles in a temperature-dependent manner. Thus, the poor thermotolerance of microbubbles is a non-negligible barrier when using CEUS to monitor the ablation range during MWA in real-time.

Multimodal Management of Colorectal Liver Metastases: State of the Art

Liver is the most common site of colorectal cancer (CRC) metastases. Treatment of CRC liver metastases (CRLM) includes different strategies, prevalently based on the clinical and oncological intent. Valid approaches in liver-limited or liver-prevalent disease include surgery, percutaneous ablative procedures (radiofrequency ablation, microwave ablation), intra-arterial perfusional techniques (chemo-embolization, radio-embolization) as well as stereotactic radiotherapy. Systemic treatments, including chemotherapy, immunotherapy and other biological agents, are the only options for patients with no chance of locoregional approaches. The use of chemotherapy in other settings, such as neoadjuvant, adjuvant or conversion therapy of CRLM, is commonly accepted in the clinical practice, although data from several clinical trials have been mostly inconclusive. The optimal integration of all these strategies, when applicable and clinically indicated, should be ever considered in patients affected by CRLM based on clinical evidence and multidisciplinary experience. Here we revised in detail all the possible therapeutic approaches of CRLM focusing on the current evidences, the studies still in progress and the often contradictory data.

Locoregional Thermal and Chemical Tumor Ablation: Review of Clinical Applications and Potential Opportunities for Use in Low- and Middle-Income Countries

This review highlights opportunities to develop accessible ablative therapies to reduce the cancer burden in LMICs.

Radiofrequency Ablation of Hepatocellular Carcinomas Adjacent to the Gallbladder Without Isolation Under Contrast-Enhanced Ultrasound Monitoring: A Comparative Study with Long Term Follow-Up

Objective

This study intends to compare the efficacy and safety between patients undergoing invasive isolation or monitoring measures and patients undergoing intra-operative contrast-enhanced ultrasound (CEUS) monitoring who underwent radiofrequency ablation (RFA) of hepatocellular carcinomas (HCC) adjacent to the gallbladder (GB).

Methods

We retrospectively assessed patients with HCC adjacent to the GB who underwent ultrasound-guided RFA. They were divided into two groups: group A was monitored under intra-operative CEUS, while group B was assisted by invasive auxiliary means. The efficacy, complications and survival were followed up and compared.

Results

Thirty-eight patients with 39 HCCs were enrolled into group A and 31 patients with 35 HCCs were enrolled into group B. The technique efficacy rates were both 100% in the two groups. There were no significant differences of the cumulative 1-, 3-, and 5-year local tumor progression, tumor-free survival and overall survival between the two groups (P = 0.851, 0.081 and 0.700, respectively). There were no significant differences of major and minor complications rates between the two groups (P = 1.000, 0.994, respectively). More importantly, no GB related complications occurred in group A.

Conclusion

Intra-operative CEUS monitoring without protective isolation of the GB might be also a potentially safe and effective method for the RFA of HCC adjacent to the GB, when compared with those assisted with invasive auxiliary means.

Conspicuousness and recurrence related factors of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules

Objective

Microwave ablation (MWA) is a minimally invasive technique for the treatment of benign thyroid nodules. The purpose of this study was to evaluate efficacy and safety of ultrasound-guided MWA in the treatment of benign thyroid nodules, and to find out the recurrence related factors, so as to provide reference for future clinical work.

Methods

This study retrospectively analyzed the patients who received ultrasound-guided MWA for benign thyroid nodules in our hospital from October 2018 to March 2020. A total of 214 patients were included in the study. We assessed thyroid volume changes (represented by volume reduction ratio VRR), the energy per 1 mL reduction in nodular volume (represented by energy volume ratio ΔE), the serum levels of free triiodide thyroid hormone (FT3), free thyroxine (FT4), thyrotropin (TSH) and complications after MWA treatment.

Results

There were a total of 306 nodules in 214 patients, including 183 (85.51%) females and 31 (14.49%) males. The median diameter and volume of the nodule were 33 mm and 8.01 mL. The VRR at 1 month, 3 months, 6 months and 12 months were 40.79%, 60.37%, 74.59% and 85.60%, respectively. In addition, MWA had a better ablation effect for small nodules (initial volume ≤ 10 mL). In recurrent studies, we found that ΔE was an independent risk factor for benign thyroid nodules (P < 0.05).

Conclusions

Ultrasound-guided MWA is effective and safe in the treatment of benign thyroid nodules. In addition, it has little damage to surrounding tissues and no effect on thyroid function. Especially, the nodules with smaller initial volume, the treatment is better. On the other hand, the energy per 1 mL reduction ΔE in nodular volume may be associated with nodular recurrence, which requires further follow-up for longer periods. At this stage, we consider that ultrasound-guided MWA can be used as one of the main clinical treatment methods for benign thyroid nodules.

Contrast-enhanced ultrasound for the preoperative assessment of laryngeal carcinoma: a preliminary study

BACKGROUND

Contrast-enhanced ultrasound (CEUS) is considered an attractive imaging technique to evaluate tumor microcirculation. However, the validity of CEUS for assessing laryngeal carcinoma is unclear.

PURPOSE

To compare the performance of CEUS with conventional US and contrast-enhanced computed tomography (CECT) in the diagnosis and preoperative T-staging of laryngeal carcinoma.

MATERIAL AND METHODS

Forty-one consecutive patients with laryngeal carcinoma underwent conventional high-frequency US, CEUS, and CECT before surgery. The CEUS characteristics of laryngeal carcinoma were recorded. The imaging findings of CEUS and conventional US were compared with CECT findings and the postoperative pathological examination.

RESULTS

CEUS showed hyperenhancement in 38 cases and isoenhancement in three cases. Homogeneous distribution of contrast agent was found in 20 cases and heterogeneous distribution in 21 cases, of which 16 cases showed local perfusion defects. In the enhanced phase, rapid entry was observed in 37 cases, synchronous entry was observed in two cases, and slow entry was observed in two cases. Rapid exit was observed in 25 cases and slow exit was observed in 16 cases. The pretherapeutic T-staging accuracy was not significantly different between conventional US, CEUS, and CECT (P ≥ 0.500). A high sensitivity and specificity were achieved by CEUS in the evaluation of involvement of thyroid cartilage.

CONCLUSION

Compared with conventional US and CECT, CEUS has a reliable initial T-staging accuracy and diagnostic properties for detecting laryngeal cartilage invasion.

Case Report: Ultrasound-Guided Percutaneous Microwave Ablation of Focal Nodular Hyperplasia in a 9-Year-Old Girl

Focal nodular hyperplasia (FNH) is a rare benign tumor-like space-occupying lesion of the liver that is especially rare in children. Since there have been no reports of malignant progression of this disease and these lesions remain unchanged for a long period of time or even disappear in some cases, it remains controversial whether clinical treatment is needed. However, if the diagnosis is unclear, the patient has symptoms or the lesion becomes enlarged during follow-up, clinical treatment should be considered. Here, we report the first case of FNH near the gallbladder treated by ultrasound-guided percutaneous microwave ablation (MWA) in a 9-year-old girl.

Is contrast enhanced ultrasonography an accurate way to diagnose gallbladder adenoma? A systematic review and meta-analysis

INTRODUCTION

Gallbladder adenoma (GA) is a precancerous neoplasm and needs surgical resection. It is difficult to differentiate adenoma from other gallbladder polyps using imaging examinations. The aim of present systematic review and meta-analysis was to evaluate the diagnostic accuracy of contrast-enhanced ultrasound in the diagnosis of gallbladder adenoma.

METHODS

The searches were conducted by two independent researchers to find the relevant studies published from 1/1/2009 until end of 30/06/2019. The search included published literature in the English language in MEDLINE via PubMed, EMBASE via Ovid, The Cochrane Library, and Trip databases. For literature published in other languages, national databases (Magiran and SID), KoreaMed, and LILACS were searched. The risk of bias of every article was evaluated by using QUADAS-2. On the basis of the results from the 2 × 2 tables, pooled measures for sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curves (AUC) along with their 95% confidence intervals (CIs) were calculated using the DerSimonian Lair methodology.

RESULTS

Overall, 868 patients were studied in the 10 studies chosen for inclusion. Of these 10 studies, 5 (50%) were retrospective and 5 (50%) were prospective. The total prevalence of gallbladder adenoma in 10 studies was 16% (95% CI 13%, 18%). The sensitivity and specificity of contrast-enhanced ultrasound were 0.846 (95% CI 0.818-0.871) and 0.870 (95% CI: 0.844-0.894), respectively. The diagnostic odds ratio was 40.807 (95% CI 18.838-88.393).

CONCLUSION

CEUS is a reliable, non-invasive, and no-radiation-exposure imaging modality with a high sensitivity and specificity for detection of gallbladder adenoma. Nonetheless, it should be applied cautiously, and large scale, well-designed trials are necessary to assess its clinical value.

Computed tomography-guided radiofrequency ablation combined with transarterial embolization assisted by a three-dimensional visualization ablation planning system for hepatocellular carcinoma in challenging locations: a preliminary study

OBJECTIVE

To assess the clinical efficacy and safety of computed tomography-guided radiofrequency ablation(CT-RFA) combined with transarterial embolization(TAE) assisted by a three-dimensional visualization ablation planning system(3DVAPS) for hepatocellular carcinoma(HCC) in challenging locations.

METHODS

Data from 62 treatment-naive patients with hepatocellular carcinoma(HCC), with 83 lesions in challenging locations, and who met the Milan criteria and underwent CT-RFA between June 2013 and June 2016 were reviewed. Patients were divided into one of two groups according to different treatment modalities: study group (TAE combined with RFA assisted by 3DVAPS [n = 32]); and control (RFA only [n = 30]). Oncological outcomes included ablation-related complications, local tumor progression (LTP), and overall survival (OS). Univariate and multivariate Cox proportional hazards regression analyses were performed to assess risk factors associated with LTP and OS.

RESULTS

HCC lesions (mean size, 1.9 ± 1.0 mm in diameter) abutting the gastrointestinal tract (n = 25), heart and diaphragm (n = 21), major vessels (n = 13), and gallbladder (n = 3) were treated. A significant difference was detected in LTP between the two groups (P = 0.034), with no significant difference in OS between the two groups (P = 0.193). There were no severe complications related to ablation. Univariate analysis revealed that sex (P = 0.046) and child-turcotte-pugh (CTP) grade (P<0.001) were risk factors for OS, whereas CTP grade and treatment method (P<0.001) were risk factors for LTP. Multivariate analysis revealed that CTP grade B (P = 0.005) was independently associated with poor OS, and RFA alone (P<0.001) was independently associated with poor LTP.

CONCLUSION

CT-RFA combined with TAE assisted by a 3DVAPS provided ideal clinical efficiency for HCC in challenging locations and was a highly safe treatment modality.