Percutaneous radiofrequency ablation of hepatocellular carcinoma: assessment of safety in patients with ascites

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.

SN, Kulkarni S, Shetty NS, Gupta A, Gupta S. Indian Society of Vascular and Interventional Radiology Expert Consensus Statements for Ablation in Hepatocellular Carcinoma: Part I

Locoregional therapies play an important role in the management of hepatocellular carcinoma (HCC). Percutaneous ablation is one of the most commonly employed nonsurgical methods for treating very early and early HCC. For small HCCs, ablation is potentially curative and competes with surgical resection. The widespread availability and the spectrum of ablative techniques mandate uniform approach among interventional radiologists. Thus, it is desirable to have a consensus regarding various aspects of liver ablation. This article represents a consensus document of the experts from the Indian Society of Vascular and Interventional Radiology involved in the care of patients with HCC. The statements are presented in two parts.

Individualized Ablation of Hepatocellular Carcinoma: Tailored Approaches across the Phenotype Spectrum

Ablation is now recommended by international guidelines for the definitive treatment of hepatocellular carcinoma (HCC). Extensive clinical studies have demonstrated outcomes comparable to surgical resection with shorter hospital stays, decreased costs, and improved quality of life. Successful ablation requires complete treatment of both tumor and margin while preserving critical adjacent structures. HCC exhibits highly variable presentations in both anatomic involvement and biology which have significant implications on choice of ablative therapy. There are now abundant ablation modalities and adjunctive techniques which can be used to individualize ablation and maximize curative results. This article provides a patient-centered summary of approaches to HCC ablation in the context of patient performance, hepatic reserve, tumor phenotype and biology, intra- and extrahepatic anatomy, and ablation technology.

Effect of Microbubble-Enhanced Ultrasound on Radiofrequency Ablation of Rabbit Liver

Microbubble-enhanced ultrasound (MEUS) can non-invasively disrupt and block liver blood perfusion. It may potentially overcome the heat sink effect during a thermal ablation and consequently enhance radiofrequency ablation (RFA) of the liver. We propose a new strategy combining RFA with MEUS. For ultrasound treatment, an 831-kHz air-backed focused transducer directed 400-cycle bursts at 4.3 MPa to the liver at a 9-Hz rate. The treatment was nucleated by a lipids microbubble forming MEUS. Eighteen surgically exposed rabbit livers were treated using MEUS combined with RFA; the other 32 livers were treated using MEUS (n = 14) or RFA (n = 18) alone and served as the controls. Contrast ultrasound imaging confirmed that MEUS treatment significantly reduced liver blood perfusion by cutting contrast peak intensities in half (44.7%-54.1%) without severe liver function damage. The ablated liver volume treated using MEUS combined with RFA was 2.8 times greater than that treated using RFA alone. In conclusion, RFA of the liver can be safely and greatly enhanced by combination with MEUS pre-treatment.

Advantages of Laparoscopic Radiofrequency Ablation Over Percutaneous Radiofrequency Ablation in Hepatocellular Carcinoma

BACKGROUND

Inoperable hepatocellular carcinoma (HCC) can be treated with laparoscopic radiofrequency ablation (LRFA), which is generally a more accurate and accessible procedure than percutaneous RFA (PRFA). However, few studies have compared survival outcomes between LRFA and PRFA in patients with HCC.

AIMS

This study aimed to compare the efficacy of LRFA and PRFA for HCC treatment.

METHODS

Patients who underwent PRFA or LRFA as an initial treatment modality between April 2005 and April 2016 were enrolled in this study. The overall and recurrence-free survival rates were examined for each patient. Additionally, propensity score matching was performed for both groups.

RESULTS

The baseline characteristics of patients in the PRFA and LRFA groups showed several minor differences. Multivariate analysis showed that the RFA method was not a critical determinant of recurrence-free or overall survival (p = 0.069 and p = 0.406). Among patients who underwent RFA as the initial treatment modality, there was no significant effect between either RFA procedures on survival. After propensity score matching, univariate analysis showed a significant difference in overall survival between PRFA and LRFA (p = 0.031). Multivariate analysis showed that LRFA is a strong factor that contributed to an improved overall survival in HCC patients (hazard ratio 0.108, p = 0.040). Furthermore, our data showed that LRFA was able to limit multiple intrahepatic recurrences, as well as prevent marginal recurrence.

CONCLUSIONS

LRFA appears to be superior to PRFA in terms of survival. LRFA may help reduce mortality in HCC patients.

Fusion imaging-guided radiofrequency ablation for hepatocellular carcinomas not visible on conventional ultrasound

OBJECTIVE

The objective of our study was to assess whether fusion imaging of conventional ultrasound and liver CT or MR images can improve the conspicuity of lesions and feasibility of percutaneous radiofrequency ablation (RFA) for the treatment of hepatocellular carcinomas (HCCs) not visible on ultrasound. Whether peritumoral anatomic landmarks can be used for the placement of an electrode in HCCs not visible on ultrasound even after image fusion was also evaluated.

MATERIALS AND METHODS

Planning ultrasound for percutaneous RFA was performed using conventional ultrasound first and then using fusion imaging later during the same session. The visibility of HCCs and feasibility of RFA on conventional ultrasound and on fusion imaging were assessed. We evaluated how many HCCs initially not visible on conventional ultrasound could be visualized and ablated after applying the fusion imaging technique. One hundred twenty HCCs not visible on conventional ultrasound in 96 patients were included.

RESULTS

When fusion imaging was applied, 38 of the 120 (31.7%) HCCs that were initially not visible could be seen and RFA was feasible. Among the remaining 82 HCCs still not visible after image fusion, 26 (31.7%) were ablated under the guidance of fusion imaging the technique based on peritumoral anatomic landmarks. Overall, 64 of 120 (53.3%) HCCs (59.4%, 57 of 96 patients) not visible on conventional ultrasound could be ablated under the guidance of the fusion imaging technique.

CONCLUSION

Fusion imaging can improve the conspicuity of HCCs and the feasibility of percutaneous RFA of HCCs not visible on conventional ultrasound. Peritumoral anatomic landmarks can be used for electrode placement in HCCs that are still not visible even after image fusion.

Complications of radiofrequency ablation of hepatic, pulmonary, and renal neoplasms

Percutaneous thermal ablation has emerged as a viable technique for treatment of numerous solid organ malignancies. As the number of these procedures increases, so do the complications that are seen. Most common complications are generally related to bleeding from the target organ during or after the procedure and from thermal injury to adjacent structures. The nature of these injuries depends on the particular organ being treated, therefore it it best to categorize them this way. We will review the more common complications seen following the ablation of tumors in the liver, kidney, and lung, discuss the clinical presentation associated with each, and suggest precautions to help avoid them in the future. Understanding the potential risks associated with this procedure is critical for treatment planning and fundamental for performing these procedures safely.