The end of cryotherapy for the treatment of nonresectable hepatic tumors?

Circulating tumour cells as biomarkers for evaluating cryosurgery on unresectable hepatocellular carcinoma

We evaluated the efficacy of pre-cryosurgery and post-cryosurgery circulating tumour cells (CTCs) as biomarkers for unresectable hepatocellular carcinoma (HCC). Real‑time qPCR was used to detect potential biomarker genes in CTCs, and magnetic-activated cell sorting (MACS) and fluorescence‑activated cell sorting (FACS) was performed on 47 patients with hepatocellular cancer who underwent cryosurgery. CTCs in the 47 patients were assessed 1 day before cryosurgery, and 7 and 30 days after cryosurgery. The number of CTCs was 17.70±5.725, 14.64±6.761 and 10.28±5.598, respectively, and this decreased significantly over time (P<0.01). ΔCt values for MAGE-3, survivin and carcinoembryonic antigen (CEA) were elevated significantly compared with those obtained before cryosurgery; 2-ΔΔCt values were <1 before cryosurgery, and were 0.63±1.56, 0.21±0.22 and 0.22±0.34 for MAGE-3, survivin and CEA, respectively, at 7 days after treatment. At 30 days after treatment, 2-ΔΔCt values for MAGE-3, survivin and CEA were 0.24±0.82, 0.03±0.07 and 0.02±0.08, indicating that gene expression in CTCs significantly decreased over time (P<0.01). CTCs were useful biomarkers for evaluating the efficacy of cryosurgery on unresectable HCC.

Ablation of hepatocellular carcinoma

Radiofrequency ablation (RFA) has gained a wide acceptance as a first-line therapeutic option for small hepatocellular carcinoma (HCC). For very early-stage HCC, despite a higher rate of local tumour progression, RFA is considered as a viable alternative to surgical resection owing to its comparable long-term survival, reduced morbidity, and greater preservation of hepatic parenchyma. For HCCs larger than 2 cm, RFA can contribute to near-curative therapy when combined with chemoembolization. RFA can be used as part of a multimodal treatment strategy for more advanced or recurrent cases, and could be a useful bridging therapy for patients who are waiting for liver transplantation. However, the use of RFA is still limited in treating large tumours and some tumours in high-risk locations. To overcome its current limitations, other ablation techniques are being developed and it is important to validate the role of other techniques for enhancing performance of ablation therapy for HCC.

Comparison of percutaneous ablation technologies in the treatment of malignant liver tumors

Tumor ablation is a minimally invasive technique used to deliver chemical, thermal, electrical, or ultrasonic damage to a specific focal tumor in an attempt to achieve substantial tumor destruction or complete eradication. As the technology continues to advance, several image-guided tumor ablations have emerged to effectively manage primary and secondary malignancies in the liver. Percutaneous chemical ablation is one of the oldest and most established techniques for treating small hepatocellular carcinomas. However, this technique has been largely replaced by newer modalities including radiofrequency ablation, microwave ablation, laser-induced interstitial thermotherapy, cryoablation, high-intensity-focused ultrasound ablation, and irreversible electroporation. Because there exist significant differences in underlying technological bases, understanding each mechanism of action is essential for achieving desirable outcomes. In this article, the authors review the current state of each ablation method including technological and clinical considerations.

Comparison of percutaneous cryoablation with microwave ablation in a porcine liver model

We compared imaging and pathological changes between argon-helium cryosurgical (AH) and microwave (MW) ablation in a porcine liver model. Immediately after ablation, computed tomography (CT) imaging showed that the area affected by MW ablation was considerably greater than that affected by AH ablation; moreover, the surface area of necrotic tissue was considerably greater in the AH group, whereas the depth of the necrotic area was similar. Seven days after ablation, the affected area had not changed much in the AH group, but it had significantly increased in the MW group; similarly, the surface and depth of the necrotic areas had not changed much in the AH group, but they had increased significantly in the MW group. The pathological findings showed similar definitive areas for both groups at both time points. The findings indicated that long time after both therapies, complete tissue necrosis can be achieved, but the extent and depth of necrosis differ: necrosis foci after AH ablation could be predicted by ice ball under CT image, and necrosis foci after MW ablation will increase obviously. MW ablation might therefore be suitable for tumors with a larger volume and simple anatomical structures, and AH ablation might be suitable for tumors with complex anatomical structures or those located near important organs. These two methods could therefore be used in combination in clinical settings, but details of the procedure need to be studied.

Percutaneous treatment of hepatocellular carcinoma in patients with cirrhosis: a comparison of the safety of cryoablation and radiofrequency ablation

PURPOSE

To compare the safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis.

MATERIALS AND METHODS

This retrospective HIPAA-compliant study received institutional review board approval. Forty-two adult patients with cirrhosis underwent image-guided percutaneous ablation of hepatocellular carcinoma from 2003 to 2011. Twenty-five patients underwent 33 cryoablation procedures to treat 39 tumors, and 22 underwent 30 radiofrequency ablation procedures to treat 39 tumors. Five patients underwent both cryoablation and radiofrequency ablation procedures. Complication rates and severity per procedure were compared between the ablation groups. Potential confounding patient, procedure, and tumor-related variables were also compared. Statistical analyses included Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests. Two-sided P-values <0.05 were considered significant.

RESULTS

The overall complication rates, 13 (39.4%) of 33 cryoablation procedures versus eight (26.7%) of 30 radiofrequency ablation procedures and severe/fatal complication rates, two (6.1%) of 33 cryoablation procedures versus one (3.3%) of 30 radiofrequency ablation procedures, were not significantly different between the ablation groups (both P=0.26). Severe complications included pneumothoraces requiring chest tube insertion during two cryoablation procedures. One death occurred within 90 days of a radiofrequency ablation procedure; all other complications were managed successfully.

CONCLUSION

No significant difference was seen in the overall safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis.

Percutaneous tumor ablation for hepatocellular carcinoma

OBJECTIVE

This report reviews the current clinical status of percutaneous ablation of hepatocellular carcinoma (HCC).

CONCLUSION

HCC is increasing in incidence. Multiple percutaneous ablation methods are now available for primary treatment or for bridging to transplantation. Percutaneous ethanol instillation and radiofrequency ablation are the most extensively evaluated percutaneous treatments for HCC. Newer technologies are being evaluated and may change future practice patterns.

Percutaneous ablation of hepatocellular carcinoma: current status

Hepatocellular carcinoma (HCC) is an increasingly common disease with dismal long-term survival. Percutaneous ablation has gained popularity as a minimally invasive, potentially curative therapy for HCC in nonoperative candidates. The seminal technique of percutaneous ethanol injection has been largely supplanted by newer modalities, including radiofrequency ablation, microwave ablation, cryoablation, and high-intensity focused ultrasound ablation. A review of these modalities, including technical success, survival rates, and complications, will be presented, as well as considerations for treatment planning and follow-up.