• Ethanol
• Hepatocellular carcinoma
• Lung neoplasms
• Neoplastic cells (circulating)
• Radiofrequency ablation

• Animals
• Mice
• Carcinoma, Hepatocellular/surgery
• Mice, Nude
• Liver Neoplasms/surgery
• Disease Models, Animal
• Lung Neoplasms
• Ethanol

• 2020A1515010653 Basic and Applied Basic Research Foundation of Guangdong Province
• 61425006 National Science Fund for Distinguished Young Scholars
• 17XD1402200 Fundamental Research Funds for Central Universities of the Central South University
• 2023Y0619 Scientific Research Fund of Education Department of Yunnan Province
• 82102047 National Natural Science Foundation of China

• Hepatocellular carcinoma (HCC)
• Liver
• Neoplasm seeding
• Radiofrequency ablation (RFA)
• Transarterial chemoembolization (TACE)

• Male
• Humans
• Aged
• Carcinoma, Hepatocellular/pathology
• Liver Neoplasms/pathology
• Retrospective Studies
• Treatment Outcome
• Catheter Ablation/methods
• Chemoembolization, Therapeutic/methods
• Radiofrequency Ablation

• Radiofrequency ablation
• electrodes
• feasibility study
• hepatocellular carcinoma

• circulating tumor cell
• in vivo flow cytometry
• prostate cancer
• radiofrequency ablation

• Hepatocellular carcinoma
• Local tumor progression
• Radiofrequency ablation

To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping during radiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatment outcomes.

The institutional review board approved this retrospective study, which included 90 consecutive patients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided into two groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with a simultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factors contributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression (LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performing comparisons between the two groups.

The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) in the popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariable analysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (odds ratio = 0.10, p = 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p = 0.479 and p = 0.424, respectively).

The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients with HCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

• Contrast media
• Explosions
• Hepatocellular carcinoma
• Liver
• Radiofrequency ablation

• Animals
• Catheter Ablation/veterinary
• Dogs
• Elasticity Imaging Techniques/methods
• Elasticity Imaging Techniques/veterinary
• Liver/pathology
• Liver/surgery
• Perfusion Imaging
• Radiofrequency Ablation/methods
• Radiofrequency Ablation/veterinary
• Tomography, X-Ray Computed

• Heat-irrigate effect
• Hepatocyte
• Radiofrequency ablation (RFA)
• Thermal damage

We experimented with different ablation methods and two types of microwave antennas to determine whether microwave ablation (MWA) increases intrahepatic pressure and to identify an MWA protocol that avoids increasing intrahepatic pressure.

MWA was performed using either a single-step standard ablation or a stepwise increment ablation paired with either a 16-gauge (G) 2-cm antenna or a 14G 4-cm antenna. We compared the maximum pressures and total ablation volumes.

The mean maximum intrahepatic pressures and ablation volumes were as follows: 16G single-step: 37±33.4 mm Hg and 4.63 cm³; 16G multistep: 31±18.7 mm Hg and 3.75 cm³; 14G single-step: 114±45.4 mm Hg and 15.33 cm³; and 14G multistep: 106±43.8 mm Hg and 10.98 cm³. The intrahepatic pressure rose during MWA, but there were no statistically significant differences between the single and multistep methods when the same gauge antennae were used. The total ablation volume was different only in the 14G groups (p<0.05).

We demonstrated an increase in intrahepatic pressure during MWA. The multistep method may be used to prevent increased intrahepatic pressure after applying the proper power.

• Ex vivo
• Intrahepatic pressure
• Liver
• Microwave ablation

We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies.

• Fabry-Perot
• ablation of tissue
• fiber optic sensors
• pressure measurement

Hepatic resection (HRx) or radiofrequency ablation may be carried out as the first-line treatment of hepatocellular carcinoma (HCC). However, we have used intraoperative microwave ablation, named microwave coagulo-necrotic therapy (MCN) as part of our strategy for the treatment of HCCs for more than 15 years. Here we describe the treatment outcomes achieved at our institution as a high-volume center for microwave ablation.

Between July 1994 and December 2010, 719 consecutive patients received MCN as their initial therapy for HCC (mean tumor size 26.9 mm, mean number of lesions 2.51) at our institute. The therapeutic survival effect, local tumor progression, and overall recurrence were prospectively evaluated and statistically analyzed.

The 1-, 3-, 5-, 7-, and 10-year overall survival rates of all 719 patients were 97.7, 79.8, 62.1, 45.3, and 34.1 %, respectively. Thirty percent of the patients had Child–Pugh class B cirrhosis and the 5-year survival rate of these patients was 46.6 %. The 5-year survival of patients with ≥4 lesions (n = 168) was 49.6 % and that of patients meeting the Milan criteria (n = 470) was 70.9 %. The 1-, 3-, 5-, 7-, and 10-year overall survival rates for 390 patients treated with MCN who had ≤3 lesions with diameter ≤3 cm were 97.9, 85.1, 70.0, 57.1, and 43.0 %. No significant differences were found between the overall survival rates after MCN and the overall survival rates in 34 patients treated with HRx during the same period at our institute and under the same (P = 0.3592), nor were there any differences in disease-free survival (P = 0.3496) and local recurrence rates between the MCN and HRx groups (P = 0.5926).

MCN is effective for the locoregional control of HCC, with results comparable to those of HRx. MCN should be considered as one of the first-choice treatments for HCC, even for patients with poor liver function or multiple lesions.

Researchers have demonstrated dead cells in radiofrequency ablation (RFA) lesions that have morphological similarities to viable tumor cells and are thus referred to as ghost cells. However, studies on how long ghost cells persist have not been systematically performed.

A tumor model was established by implanting VX2 tumor tissue into the livers of 48 New Zealand rabbits. Two weeks later, these tumors were eliminated with RFA. The lesions were resected at 0 weeks, 1 week, 2 weeks, 4 weeks, 8 weeks, or 12 weeks after treatment, and samples were stained either with hematoxylin and eosin (HE) or nicotinamide adenine dinucleotide (NADH). The presence of the cells and the morphological changes that they underwent were examined by light microscopy.

Four weeks after RFA, there were no obvious morphological changes observed in HE-stained ghost cells, and NADH staining revealed no viable cells. Eight weeks after RFA, the cell structure became indistinct. Twelve weeks after RFA, ghost cells were no longer present.

The morphological characteristics of ghost cells are maintained for at least 4 weeks, during which time HE staining cannot be used to differentiate ghost cells from residual tumor cells. NADH staining for cell viability is necessary to differentiate residual tumor cells from ghost cells. This evidence adds to our understanding of the mechanisms of RFA when used on solid tumors.

• Animals
• Carcinoma, Squamous Cell/pathology
• Carcinoma, Squamous Cell/radiotherapy
• Catheter Ablation
• Cell Survival
• Female
• Male
• Neoplasm Transplantation
• Neoplasm, Residual/pathology
• Rabbits

• Animals
• Blood Pressure
• Catheter Ablation/adverse effects
• Catheter Ablation/methods
• Laparotomy/methods
• Liver/blood supply
• Liver/surgery
• Liver Circulation
• Swine

• Animals
• Catheter Ablation/adverse effects
• Cell Line, Tumor
• Colorectal Neoplasms/pathology
• Colorectal Neoplasms/physiopathology
• Disease Models, Animal
• Hypoxia/physiopathology
• Liver/pathology
• Liver/physiopathology
• Liver Neoplasms/physiopathology
• Liver Neoplasms/secondary
• Male
• Mice
• Necrosis
• Neoplasm Recurrence, Local/etiology
• Neoplasm Recurrence, Local/physiopathology
• Rats

• 07-0552 Worldwide Cancer Research

AIM: To evaluate the effects of combined radiofrequency ablation and transcatheter arterial embolization with iodized oil on ablation time, maximum output, coagulation diameter, and portal angiography in a porcine liver model.

METHODS: Radiofrequency ablation (RFA) was applied to in vivo livers of 10 normal pigs using a 17-gauge 3.0 cm expandable LeVeen RF needle electrode with or without transcatheter arterial embolization (TAE) with iodized oil (n = 5). In each animal, 2 areas in the liver were ablated. Direct portography was performed before and after RFA. Ablation was initiated at an output of 30 W, and continued with an increase of 10 W per minute until roll-off occurred. Ablation time and maximum output until roll-off, and coagulated tissue diameter were compared between the 2 groups. Angiographic changes on portography before and after ablation were also reviewed.

RESULTS: For groups with and without TAE with iodized oil, the ablation times until roll-off were 320.6 ± 30.9 seconds and 445.1 ± 35.9 seconds, respectively, maximum outputs were 69.0 ± 7.38 W and 87.0 ± 4.83 W and maximal diameters of coagulation were 41.7 ± 3.85 mm and 33.2 ± 2.28 mm. Significant reductions of ablation time and maximum output, and significantly larger coagulation diameter were obtained with RFA following TAE with iodized oil compared to RFA alone. Portography after RFA following TAE with iodized oil revealed more occlusion of the larger portal branches than with RFA alone.

CONCLUSION: RFA following TAE with iodized oil can increase the volume of coagulation necrosis with lower output and shorter ablation time than RFA alone in normal pig liver tissue.

• Liver
• Radiofrequency ablation
• Transcatheter arterial embolization
• Iodized oil
• Angiography
• Hepatocellular carcinoma

• Angiography
• Animals
• Blood Coagulation/drug effects
• Catheter Ablation/methods
• Embolization, Therapeutic/methods
• Hepatic Artery/pathology
• Hepatic Artery/physiopathology
• Iodized Oil/pharmacology
• Liver/blood supply
• Liver/pathology
• Liver/surgery
• Liver Neoplasms/blood supply
• Liver Neoplasms/pathology
• Liver Neoplasms/surgery
• Male
• Models, Animal
• Necrosis
• Portography
• Regional Blood Flow/drug effects
• Swine

Radio frequency ablation (RFA) has been accepted clinically as a useful local treatment for hepatocellular carcinoma (HCC). However, intrahepatic recurrence after RFA has been reported which might be attributable to increase in intra-tumor pressure during RFA. To reduce the pressure and ablation time, we developed a novel method of RFA, a multi-step method in which a LeVeen needle, an expansion-type electrode, is incrementally and stepwise expanded. We compared the maximal pressure during ablation and the total ablation time among the multi-step method, single-step method (a standard single-step full expansion with a LeVeen needle), and the method with a cool-tip electrode. Finally, we performed a preliminary comparison of the ablation times for these methods in HCC cases.

A block of pig liver sealed in a rigid plastic case was used as a model of an HCC tumor with a capsule. The multi-step method with the LeVeen electrode resulted in the lowest pressure as compared with the single-step or cool-tip methods. There was no significant difference in the ablation time between the multi-step and cool-tip ablation methods, although the single-step methods had longer ablation times than the other ablation procedures. In HCC cases, the multi-step method had a significantly shorter ablation time than the single-step or cool-tip methods.

We demonstrated that the multi-step method was useful to reduce the ablation time and to suppress the increase in pressure. The multi-step method using a LeVeen needle may be a clinically applicable procedure for RFA.