Thermal ablation of hepatocellular carcinoma

Interventional oncology in children: Where are we now?

Paediatric Interventional Oncology (IO) lags behind adult IO due to a scarcity of specific outcome data. The suboptimal way to evolve this field is relying heavily on adult experiences. The distinct tumour types prevalent in children, such as extracranial germ cell tumours, sarcomas, and neuroblastoma, differ strongly from those found in adults, presenting a completely different biological behaviour. Compounding this challenge, paediatric interventional radiology often employs adapted or off-label techniques, potentially compromising optimal outcomes. This review outlines the present indications for interventional radiology in paediatric cancer, from biopsy to supportive care, including complication management. It emphasises the role of locoregional approaches, and explores the status of common paediatric oncological diseases, highlighting areas where IO has made progress identifying potential opportunities for future advancements in this evolving field.

Comparison of Surgical Resection and Radiofrequency Ablation in Elderly Patients with Hepatocellular Carcinoma

BACKGROUND/AIMS

The aim of this study was to examine whether the efficacy of radiofrequency ablation (RFA) and surgical resection (SR) are comparable for hepatocellular carcinoma (HCC) less than 3 cm in elderly individuals aged 65 years or older.

METHODS

We used the National Health Insurance Service claims data in Korea, which was linked with liver cancer stage data from the Central Cancer Registry of the National Cancer Center, as well as death data from the National Statistical Office. Out of the 9213 registrants, we focused on 141 patients who underwent SR and 225 patients who underwent RFA when they were 65 years or older. To ensure comparability, a 1:1 propensity score (PS) matching was conducted.

RESULTS

The SR group had lower performance status and better liver function compared to the RFA group. Tumor diameter was larger in the SR group than in the RFA group (2.1 cm vs. 1.7 cm), and the proportion of stage II cases was higher (62.4% vs. 33.8%). After PS matching, the mortality rate in the RFA group did not significantly differ from the SR group (HR 1.33, 95% CI 0.86-2.06, P = 0.19). Also, liver related mortality was similar between the SR and RFA group after matching (log rank P = 0.13). However, recurrence free survival was significantly longer in the SR group than RFA group before and after matching (log rank P = 0.03).

CONCLUSION

In patients aged 65 years or older with resectable HCC, RFA demonstrates a therapeutic effect comparable to SR.

Intraoperative electrochemotherapy of the posterior resection surface after pancreaticoduodenectomy: Preliminary results of a hybrid approach treatment of pancreatic cancer

BACKGROUND

Despite extensive research in recent decades, pancreatic cancer continues to be among the most lethal forms of cancer, with no substantial increase in survival rates. Local recurrences account for approximately 30 per cent of all disease recurrences. With the intent to improve survival, we designed a novel, hybrid treatment strategy consisting of surgical resection and additional intraoperative electrochemotherapy of the posterior resection surface. We present the study protocols and preliminary findings of a prospective pilot study investigating this treatment approach.

METHODS

Consenting patients with resectable pancreatic head ductal adenocarcinoma who met the inclusion criteria were enrolled in the study. After surgical resection, electrochemotherapy with bleomycin was performed using plate electrodes to cover the area between anatomical landmarks.

RESULTS

Electrochemotherapy of the posterior resection surface was feasible in all 7 patients. We observed pancreatic fistula grade B in only one patient; all other noted complications were Clavien-Dindo grade 2 or less. The hospital mortality was 0%.

CONCLUSIONS

Our preliminary results suggest that a hybrid approach combining surgery with intraoperative electrochemotherapy is safe and feasible.

A novel tissue-mimicking phantom for US/CT/MR-guided tumor puncture and thermal ablation

AIM

This study aimed to develop a novel tumor-bearing tissue phantom model that can be used for US/CT/MR-guided tumor puncture and thermal ablation.

METHODS

The phantom model comprised two parts: a normal tissue-mimicking phantom and a tumor-mimicking phantom. A normal tissue phantom was prepared based on a polyacrylamide gel mixed with thermochromic ink. Moreover, a spherical phantom containing contrast agents was constructed and embedded in the tissue phantom to mimic a tumor lesion. US/CT/MR imaging features and thermochromic property of the phantom model were characterized. Finally, the utility of the phantom model for imaging-guided microwave ablation training was examined.

RESULTS

The tumor phantom containing contrast agents showed hyper-echogenicity, higher CT numbers, and lower T2 signal intensity compared with the normal tissue phantom in US/CT/MR images. Consequently, we could locate the position of the tumor in US/CT/MR imaging and perform an imaging-guided tumor puncture. When the temperature reached the threshold of 60 °C, the phantom exhibited a permanent color change from cream white to magenta. Based on this obvious color change, our phantom model could clearly map the thermal ablation region after thermotherapy.

CONCLUSIONS

We developed a novel US/CT/MR-imageable tumor-bearing tissue model that can be used for imaging-guided tumor puncture and thermal ablation. Furthermore, it allows visual assessment of the ablation region by analyzing the obvious color change. Overall, this phantom model could be a good training tool in the field of thermal ablation.

Aggressive local treatment for recurrent intrahepatic cholangiocarcinoma—Stereotactic radiofrequency ablation as a valuable addition to hepatic resection

Background

To evaluate the efficacy, safety and overall clinical outcome of local treatment for recurrent intrahepatic cholangiocellular carcinoma after hepatic resection.

Methods

Between 2007 and 2019 72 consecutive patients underwent hepatic resection for primary intrahepatic cholangiocellular carcinoma. If amenable, recurrent tumors were aggressively treated by HR or stereotactic radiofrequency ablation with local curative intent. Endpoints consisted of morbidity and mortality, locoregional and de novo recurrence, disease free survival, and overall survival.

Results

After a median follow-up of 28 months, recurrence of intrahepatic cholangiocellular carcinoma was observed in 43 of 72 patients undergoing hepatic resection (60.3%). 16 patients were subsequently treated by hepatic resection (n = 5) and stereotactic radiofrequency ablation (n = 11) with local curative intention. The remaining 27 patients underwent palliative treatment for first recurrence. Overall survival of patients who underwent repeated aggressive liver-directed therapy was comparable to patients without recurrence (p = 0.938) and was better as compared to patients receiving palliative treatment (p = 0.018). The 5-year overall survival rates for patients without recurrence, the repeated liver-directed treatment group and the palliative treatment group were 54.3%, 47.7% and 12.3%, respectively. By adding stereotactic radiofrequency ablation as an alternative treatment option, the rate of curative re-treatment increased from 11.9% to 37.2%.

Conclusion

Repeated hepatic resection is often precluded due to patient morbidity or anatomical and functional limitations. Due to the application of stereotactic radiofrequency ablation in case of recurrent intrahepatic cholangiocellular carcinoma, the number of patients treated with curative intent can be increased. This leads to favorable clinical outcome as compared to palliative treatment of intrahepatic cholangiocellular carcinoma recurrence.

Predicting the coagulation volume induced by microwave ablation of hepatocellular carcinoma: the role of deposited energy, ex-vivo bovine liver charts and central hyperdense area on post-treatment CT

PURPOSE

To study the correlation between the overall coagulation zone (A) attained in percutaneous microwave ablation (MWA) of hepatocellular carcinomas (HCC) and: (1) the hyperdense zone (C) visible in the central part of zone A on post-treatment unenhanced CT scans; (2) the deposited energy; (3) the coagulation zones observed on ex-vivo bovine liver.

MATERIALS AND METHODS

The post-procedural computed tomography (CT) scans of HCCs treated with a single energy deployment through the same 2450 MHz MWA system were retrospectively analyzed, retrieving the dimensions of A and C zones and the deposited energy (E). Ex-vivo bovine liver MWA with the same system were performed and analyzed to determine the same quantities by gross-pathologic examination and CT imaging.

RESULTS

A total of 101 HCC treatments were analyzed. The average coagulation volumes increased linearly with deposited energy (1.11 cc/kJ, R² = 0.90, 4.2 kJ ≤ E ≤ 48 kJ), similarly to ex-vivo findings (1.38 cc/kJ, R² =0.97, 7.2 kJ ≤ E ≤ 144 kJ). The long axis (L) and short axis (D) of zones A and C held a fairly constant ratio both in-vivo (L_C/L_A=0.43 ± 0.13; D_C/D_A=0.42 ± 0.10) and ex-vivo (L_C/L_A = 0.49 ± 0.07; D_C/D_A = 0.28 ± 0.06).

CONCLUSIONS

The average dimensions of the ablation zone induced by the considered system on HCC increase linearly with the deposited energy and are fairly well predicted by the corresponding ex-vivo dimensions. The ratio between each linear dimension of A and C zones was found to be roughly constant over a large deposited energy span, both ex-vivo and in-vivo.

Enhanced antitumor efficacy through microwave ablation combined with a dendritic cell-derived exosome vaccine in hepatocellular carcinoma

AIM

To investigate the antitumor efficacy of microwave ablation combined with dendritic cell-derived exosomes (Dex) or dendritic cells (DC) in treating hepatocellular carcinoma using a tumor-bearing mouse model.

METHODS

We used a bilateral tumor-bearing mouse model treated with MWA, MWA + DC (DC-combined group) or MWA + Dex (Dex-combined group). Following tumor ablation on one side, the tumor volume on the contralateral side was monitored. The proportions of CD8⁺ (cytotoxic) T cells and regulatory T (Treg) cells in the spleen were analyzed by flow cytometry, and the number of CD8⁺ T cells and Treg cells in tumor sites was detected by immunohistochemistry. The concentration of interleukin-10 and interferon-γ in plasma was identified using enzyme-linked immunosorbent assay.

RESULTS

The combination therapy significantly inhibited tumor growth compared with MWA monotherapy. In addition, the tumor immune microenvironment was significantly improved in HCC mice in the combination therapy groups compared to MWA group demonstrated by an increased number of CD8⁺ T cells and a decreased number of Treg cells in tumor sites. A lower proportion of Treg cells were observed in the spleen in the combination therapy groups compared to MWA group. Moreover, the concentration of plasma IFN-γ increased, and the concentration of plasma IL-10 decreased in the combination therapy groups compared to the MWA group. However, there was no statistical difference between the Dex-combined group and the DC-combined group in the comparisons mentioned above.

CONCLUSIONS

Our results provide evidence that MWA combined with Dex can significantly inhibit tumor growth and improve the immune microenvironment compared to MWA alone. Furthermore, the immune-enhancing effect of Dex and DC was equivalent in our combination therapy strategy.

Percutaneous microwave ablation applications for liver tumors: recommendations for COVID-19 patients

Microwave ablation (MWA) is an alternative locoregional therapy to surgical resection of solid tumors in the treatment of malignancies, and is widely used for hepatic tumors. It has a slightly higher overall survival (OS) rate compared to external beam radiation therapy (EBRT), and proton beam therapy (PBT), and better long-term recurrence-free OS rate compared to radiofrequency ablation (RFA). In this paper, current commercial devices, most recent noncommercial designs, and the principles behind them alongside the recently reported developments and issues of MWA are reviewed. The paper also provides microscopic insights on effects of microwave irradiation in the body. Our review shows that MWA is a safe and effective, minimally invasive method with high ablation completion rates. However, for large tumors, the completion rates slightly decrease, and recurrences increase. Thus, for large tumors we suggest using a cooled shaft antenna or multiple antenna placements. Comparisons of the two common ablation frequencies 915 MHz and 2.45 GHz have shown inconsistent results due to non-identical conditions. This review suggests that 915 MHz devices are more effective for ablating large tumors and the theory behind MWA effects corroborates this proposition. However, for small tumors or tumors adjacent to vital organs, 2.45 GHz is suggested due to its more localized ablation zone. Among the antenna designs, the double-slot antenna with a metallic choke seems to be more effective by localizing the radiation around the tip of the antenna, while also preventing backward radiation towards the skin. The review also pertains to the use of MWA in COVID-19 patients and risk factors associated with the disease. MWA should be considered for COVID-19 patients with hepatic tumors as a fast treatment with a short recovery time. As liver injury is also a risk due to COVID-19, it is recommended to apply liver function tests to monitor abnormal levels in alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, and other liver function indicators.

Applications of Elastography in Ablation Therapies: An Animal Model In Vivo Study

Background: Ablation therapies are one of the main local treatments for solid organ tumors. After applying any ablation therapy, few days should be waited to perform an imaging study and analyze the result. In this work, we analyzed the correlation between elastography monitoring after procedure and the result of ablation. The objective of this study is to determine tissue changes in vivo in short term after the application of ablation systems using different diagnostic imaging methods. Materials and Methods: Descriptive study in an in vivo swine model. Different types of ablation therapies (radiofrequency ablation, microwave ablation [MWA], and LASER ablation [LA]) were applied in the liver and kidneys. We compared their results by medical image monitoring (ultrasound, computed tomography, elastography) and macroscopic analysis. Results: All the animals survived the procedures. No major intraoperative complications were reported. We determined the characteristics of each procedure. MWA session was faster than the other types of ablation therapies. Regarding ablation area diameters, the largest was achieved with MWA and the smallest with LA. Macroscopically, we observed a central ablation zone, a peripheral ablation zone, and surrounding normal tissue. It was correlated with elastography images. Conclusion: Monitoring of the results of ablation therapies shortly after their application is possible through imaging studies. It allows determining the size of the ablation zone, its characteristics, ruling out complications, and its early results. Elastography could efficiently support this goal.

Effects of thermal ablation on Treg/Th17 in hepatocellular carcinoma of mice

The study was aimed to explore the possible function of thermal ablation treatment on T helper 17 (Th17) cells and regulatory T (Treg) cells in transplantation of hepatocellular carcinoma in mice. In total, 60 male C57BL/6 mice were divided into control group, model group, and treat group. Flow cytometry was used to detect the frequency of Th17 and Treg cells in peripheral blood. The levels of interleukin (IL)-17, IL-23, IL-10, and transforming growth factor beta (TGF-β) in serum were detected by enzyme-linked immunosorbent assay (ELISA).The levels of IL-17, RORγt, Foxp3, and TGF-β mRNA in tumor tissues were detected by real-time fluorescence quantitative PCR (qRT-PCR). Compared with the model group, tumor size was significantly decreased after thermal ablation treatment. After treatment, the frequency of Th17 cells in peripheral blood was significantly decreased, while the frequency of Treg cells was profoundly increased ( P < 0.05). The levels of IL-17 and IL-23 were significantly downregulated, while IL-10 and TGF-β levels were upregulated ( P < 0.05). IL-17 and RORγt mRNA levels in tumor tissues were significantly decreased ( P < 0.05), and Foxp3 and TGF-β mRNA levels were significantly increased ( P < 0.05). Thermal ablation treatment plays a positive role in the treatment of hepatoma in mice through affecting the imbalance of Th17/Treg cells.

Eye Opener to EtOH Ablation for Juxta-Cardiac Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is notoriously refractory to systemic chemotherapy, mandating an interventional approach. Mortality may be avoided by neutralizing rapidly growing tumors that approach the heart and major vessels. When the risk/benefit ratio of surgery is unacceptable, percutaneous ablation can achieve remarkable results. High volumes of flowing blood adjacent to the treatment area may impact the ability to reliably achieve an adequate ablation margin for modalities that rely on extreme temperatures to destroy malignant cells. Ethanol ablation is safe, efficacious, and unaffected by this "thermal sink" effect. This report describes a juxta-cardiac (JC) HCC in segment 4a measuring 35 × 26 mm, which exhibited rapid growth until it was abutting the pericardium and 7.5 mm from the chamber of the right ventricle (RV).

Methods

One 21-gauge needle was inserted using direct CT fluoroscopy into the center of the hepatic mass. In order to confirm the position of the needle, 0.5 mL of diluted Visipaque was injected. Then, under CT fluoroscopy guidance, a mixture of 1 mL of Ethiodol and 10 mL of 98% dehydrated alcohol was slowly injected into the mass.

Results

Repeat CT scan 1 month post-ablation demonstrated decreased arterial enhancement and dense Ethiodol throughout the tumor consistent with ablation. Tumor size decreased to 30 × 23 mm with a distance of 12.4 mm from the chamber of the RV.

Conclusion

Pericardial involvement or large vessels near the treatment area may limit the use of thermal ablation techniques for JC HCC. Percutaneous, intratumoral ethanol injection provides safe and effective alternative that is not subject to the "thermal sink" effect.

Thermal ablation of intrahepatic cholangiocarcinoma: Safety, efficacy, and factors affecting local tumor progression

PURPOSE

To evaluate the safety and oncologic efficacy of percutaneous thermal ablation of intrahepatic cholangiocarcinoma (ICC) and identify risk factors for local tumor progression (LTP).

MATERIALS AND METHODS

Retrospective review of an institutional tumor ablation registry demonstrated that 20 patients (9 males, 11 females; mean age 62.5 ± 15.8 years) with 50 ICCs (mean size 1.8 ± 1.3 cm) were treated with percutaneous radiofrequency ablation (RFA) or microwave ablation (MWA) between 2006 and 2015. Thirty-eight of the treated ICCs (76%) were metastases that developed after surgical resection of the primary tumor. Patient demographics, procedure technical parameters, and clinical outcomes were reviewed. A Cox proportional hazards model was used to examine the risk of LTP by ablation modality. Survival analyses were performed using the Kaplan-Meier method.

RESULTS

Mean imaging follow-up time was 41.5 ± 42.7 months. Forty-four (88%) ICCs were treated with RFA, and 6 (12%) with MWA. Eleven (22%) cases of LTP developed in 5 (25%) patients. The median time to LTP among these 11 tumors was 7.1 months (range, 2.3-22.9 months). Risk of LTP was not significantly different for ICCs treated with MWA compared to RFA (HR 2.72; 95% CI 0.58-12.84; p = 03.21). Median disease-free survival was 8.2 months (1.1-70.4 months), and median overall survival was 23.6 months (7.4-122.5 months). No major complication occurred.

CONCLUSIONS

Percutaneous thermal ablation is a safe and effective treatment for patients with ICCs and may be particularly valuable in unresectable patients, or those who have already undergone hepatic surgery. Tumor size and ablation modality were not associated with LTP, whereas primary tumors and superficially located tumors were more likely to subsequently recur.

Effects of intratumoral injection of immunoactivator after microwave ablation on antitumor immunity in a mouse model of hepatocellular carcinoma

This study investigated the effects of intratumoral injection of immunoactivator after microwave ablation on antitumor immunity in a mouse model of hepatocellular carcinoma. Hepatocellular carcinoma cell line Hepa1-6 was subcutaneously injected into C57/B6 mice to establish a mouse model of hepatocellular carcinoma. When tumor diameter reached 8 mm, microwave ablation was performed for 3 min with temperature controlled at 55°C. Cytokine sustained-release microspheres (CytoMPS) containing human interleukin-2 (hIL-2) and mouse granulocyte macrophage colony-stimulating factor (mGM-CSF) were injected into the tumor of mice in the experimental group (n=5) at 3, 7 and 14 days after ablation, while sustained-release microspheres containing no cytokine were used in the control group (n=5). Mice were sacrificed on the 17th day after ablation, and CD4⁺ and CD8⁺ T cells in peripheral blood were counted by flow cytometry. Spleen was collected from the mice to isolate lymphocytes. Lactate dehydrogenase (LDH) release assay was used to determine the cytotoxicity of spleen cells to Hepal-6 cells. Injection of CytoMPS after ablation increased the percentage of CD4⁺ and CD8⁺ T cells in peripheral blood. Cytotoxicity of CD8⁺ CTL to Hepal-6 is significantly higher in experimental group than in control group (P<0.01). The results showed that intratumoral injection of CytoMPS containing hIL-2 and mGM-CSF can significantly increase the proportion of CD4⁺ and CD8⁺ T cells in blood and increase the cytotoxicity of CTL cells to tumor cells in mice with hepatocellular carcinoma.

Immunomodulation characteristics by thermal ablation therapy in cancer patients

AIM

Thermal ablation therapy has recently emerged as a promising noninvasive treatment modality for localized solid malignancies. Except its direct tumor-cell-killing effect on local tumor tissues, the immunomodulatory effect has also long been noticed which too has substantial effect on clinical outcome, but it is complicated. Though much has been investigated and rich evidences have been achieved, the fundamental state and profile of immunomodulation by thermal ablation in cancer patients, its exact mechanism, especially the systematic mechanism, and its effect on antitumor immunity remain unclear.

METHODS

In this study, we dynamically monitored the immunomodulation by thermal ablation through combined analysis of peripheral lymphocyte populations, functional T cell subtype Th1 (CD3+CD4+IFN-r+), Th2 (CD3+CD4+IL-4+), Tc1 (CD3+CD8+IFN-r+), Tc2 (CD3+CD8+IL-4+) and mRNA expression of several immune-active and -suppressive molecules including CD25, CD28, cytotoxic T-lymphocyte-associated protein 4, programmed cell death protein 1, Foxp3, transforming growth factor beta (TGF-β) and interleukin (IL-10) in 16 cancer patients.

RESULTS

The results show that local cancer thermal ablation modulated the cellular immunity characterized by obviously downregulation of regulatory T cells (Treg) and cytotoxicity T cells followed by CD4, CD8 and suppressor T cells (Ts), but upregulation of natural killer (NK) cells and mRNA expression of TGF-β and IL-10, suggesting a slight inhibition of the cellular immunity which may affect antitumor immunity.

CONCLUSIONS

We suggest a further immunomodulation therapy after thermal therapy for recovering a Th1- and Tc1-dominant immune response for pursuing a better long-term antitumor immunity.

Early complications after percutaneous radiofrequency ablation for hepatocellular carcinoma: an analysis of 1,843 ablations in 1,211 patients in a single centre: experience over 10 years

AIM

To evaluate the incidence of adverse events and associated factors after radiofrequency ablation (RFA) in patients with hepatocellular carcinoma within 30 days.

MATERIALS AND METHODS

The early complications that occurred within 30 days after RFA at a single institution from January 2000 to July 2010 were reviewed in order to evaluate the morbidity, mortality, and risk factors associated with the complications. In total, 1,211 patients (845 men, 70.5%) with a mean age of 68 years (range, 27-88 years) underwent 1,843 RFA procedures.

RESULTS

The overall incidence rate of complications was 6.8% (125 cases). Major complications (n=36, 2%) included liver abscess (n=15, 0.8%), intraperitoneal bleeding (n=8, 0.4%), liver failure (n=5, 0.3%), variceal bleeding (n=3, 0.2%), haemothorax (n=2, 0.1%), cholecystitis (n=2, 0.1%), and bowel perforation (n=1, 0.1%). Among the minor complications (n=89, 4.8%), the most common was the post RFA syndrome accompanied by pain and fever (n=75, 4.1%). Other minor complications included significant pleural effusion (n=7, 0.4%), skin wound infection (n=4, 0.2%), and thermal injuries to the skin (n=3, 0.2%). Procedural infections significantly increased with tumour size (OR=1.379; 95% confidence interval [CI], 1.191-1.579; p<0.001), and multiple overlapping ablations (OR=1.118; 95% CI, 1.019-1.227, p=0.018). Thrombocytopenia (<50,000/μl), prothrombin time, and serum albumin level were significantly associated with post-RFA bleeding episodes (p=0.041, p=0.021, and p=0.003, respectively). The overall mortality rate was 0.3% (three cases of hepatic failure, two case of sepsis, and one case of renal failure).

CONCLUSIONS

RFA is a safe and effective local treatment for hepatocellular carcinoma. Careful selection of patients and appropriate RFA planning could decrease procedural mortality and morbidity.

"Hepatocellular carcinoma: A life-threatening disease"

An estimated rise in liver cancer incidence will increase to 95374 new cases by 2020. Hepatocellular Carcinoma (HCC), the most common primary malignant tumour of the liver, is considered to be the third leading cause of all cancer-related deaths and fifth common cancer worldwide. The reported data shows that the rate of HCC incidence in male population is three to four times higher compared with the female population. In the United States, HCV-induced liver cancer is increasing very fast because of the lack of proper treatment option. There are various treatment strategies available for HCC like liver transplantation, resection, ablation, embolization and chemotherapy still the prognosis is destitute. If the patient is eligible, liver transplantation is the only therapeutic option that may give around 90% survival rate, but the scarcity of liver donor limits its broad applicability. A sudden address is necessary to develop specific drugs, personalized medicine, for HCC.

Efficacy and survival analysis of percutaneous radiofrequency versus microwave ablation for hepatocellular carcinoma: an Egyptian multidisciplinary clinic experience

BACKGROUND

Hepatocellular carcinoma (HCC) is a primary tumor of the liver with poor prognosis. For early stage HCC, treatment options include surgical resection, liver transplantation, and percutaneous ablation. Percutaneous ablative techniques (radiofrequency and microwave techniques) emerged as best therapeutic options for nonsurgical patients.

AIMS

We aimed to determine the safety and efficacy of radiofrequency and microwave procedures for ablation of early stage HCC lesions and prospectively follow up our patients for survival analysis.

PATIENTS AND METHODS

One Hundred and 11 patients with early HCC are managed in our multidisciplinary clinic using either radiofrequency or microwave ablation. Patients are assessed for efficacy and safety. Complete ablation rate, local recurrence, and overall survival analysis are compared between both procedures.

RESULTS

Radiofrequency ablation group (n = 45) and microwave ablation group (n = 66) were nearly comparable as regards the tumor and patients characteristics. Complete ablation was achieved in 94.2 and 96.1% of patients managed by radiofrequency and microwave ablation techniques, respectively (p value 0.6) with a low rate of minor complications (11.1 and 3.2, respectively) including subcapsular hematoma, thigh burn, abdominal wall skin burn, and pleural effusion. Ablation rates did not differ between ablated lesions ≤ 3 and 3-5 cm. A lower incidence of local recurrence was observed in microwave group (3.9 vs. 13.5% in radiofrequency group, p value 0.04). No difference between both groups as regards de novo lesions, portal vein thrombosis, and abdominal lymphadenopathy. The overall actuarial probability of survival was 91.6% at 1 year and 86.1% at 2 years with a higher survival rates noticed in microwave group but still without significant difference (p value 0.49).

CONCLUSION

Radiofrequency and microwave ablations led to safe and equivalent ablation and survival rates (with superiority for microwave ablation as regards the incidence of local recurrence).

Systematic evaluation of percutaneous radiofrequency ablation versus percutaneous ethanol injection for the treatment of small hepatocellular carcinoma: a meta-analysis

BACKGROUND

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) have been used for patients with hepatocellular carcinoma (HCC). However, which therapy is superior remains to be further elucidated. We aimed to conduct a systematic review to assess survival and local tumor recurrence rate with RFA compared with PEI therapy for HCC.

METHODS

We conducted systematic review and meta-analysis of randomized controlled trials (RCTs) published up to 2014 in PubMed, MEDLINE, EMBASE, EBSCO, Springer, Ovid and the Cochrane library. Only RCTs that evaluated survival rate and occurrence of HCC between RFA and PEI therapy were included. The OR (odds ratio) with a 95% confidence interval (CI) was calculated by the Revman 5.0 software.

RESULTS

A total of six studies including 983 HCC patients were eligible for this analysis. The survival rate showed a significant benefit under RFA therapy over PEI at 1-year (P = 0.02, OR = 1.88, 95% CI: 1.09 to 3.22), 2-years (P = 0.0003, OR = 2.06, 95% CI: 1.39 to 3.05) and 3-years (P = 0.0007, OR = 1.68, 95% CI: 1.25 to 2.27). Likewise, RFA achieved significantly lower rates of local tumor recurrence over PEI at 1-year (P = 0.002, OR = 0.43, 95% CI: 0.26 to 0.73), 2-year (P = 0.03, OR = 0.33, 95% CI: 0.12 to 0.88) and 3-year (P = 0.003, OR = 0.61, 95% CI: 0.43 to 0.84).

CONCLUSIONS

The current evidence suggests that RFA is superior to PEI in better survival and local disease control for small HCCs <5 cm in diameter and that RFA is worthy of promotion in clinical applications.

Thermal ablation of liver metastases from colorectal cancer: radiofrequency, microwave and laser ablation therapies

Surgery is currently considered the treatment of choice for patients with colorectal cancer liver metastases (CRLM) when resectable. The majority of these patients can also benefit from systemic chemotherapy. Recently, local or regional therapies such as thermal ablations have been used with acceptable outcomes. We searched the medical literature to identify studies and reviews relevant to radiofrequency (RF) ablation, microwave (MW) ablation and laser-induced thermotherapy (LITT) in terms of local progression, survival indexes and major complications in patients with CRLM. Reviewed literature showed a local progression rate between 2.8 and 29.7 % of RF-ablated liver lesions at 12-49 months follow-up, 2.7-12.5 % of MW ablated lesions at 5-19 months follow-up and 5.2 % of lesions treated with LITT at 6-month follow-up. Major complications were observed in 4-33 % of patients treated with RF ablation, 0-19 % of patients treated with MW ablation and 0.1-3.5 % of lesions treated with LITT. Although not significantly different, the mean of 1-, 3- and 5-year survival rates for RF-, MW- and laser ablated lesions was (92.6, 44.7, 31.1 %), (79, 38.6, 21 %) and (94.2, 61.5, 29.2 %), respectively. The median survival in these methods was 33.2, 29.5 and 33.7 months, respectively. Thermal ablation may be an appropriate alternative in patients with CRLM who have inoperable liver lesions or have operable lesions as an adjunct to resection. However, further competitive evaluation should clarify the efficacy and priority of these therapies in patients with colorectal cancer liver metastases.

Local control of perivascular malignant liver lesions using percutaneous irreversible electroporation: initial experiences

PURPOSE

This study was designed to assess efficacy and safety in the treatment of perivascular malignant liver lesions using percutaneous, computed tomography (CT)-guided irreversible electroporation (IRE).

METHODS

Fourteen patients (mean age 58 ± 11 years) with 18 malignant liver lesions were consecutively enrolled in this study. IRE was performed in patients not eligible for surgery and lesions abutting large vessels or bile ducts. Follow-up exams were performed using multislice-CT (MS-CT) or MRI.

RESULTS

Medium lesion diameter was 20 ± 5 mm. Ten of 14 (71 %) were successfully treated with no local recurrence to date (mean follow-up 388 ± 160 days). One case left initial tumor control unclear and additional RFA was performed 4 weeks after IRE. Complications occurred in 4 of 14 (29 %) cases. In one case, intervention was terminated and abdominal bleeding required laparotomy. In two cases, a postinterventional hematothorax required intervention. In another case, abdominal bleeding could be managed conservatively. No complications related to the bile ducts occurred.

CONCLUSIONS

Percutaneous IRE seems to be effective in perivascular lesions but is associated with a higher complication rate compared with thermoablative techniques.

Irreversible electroporation ablation: creation of large-volume ablation zones in in vivo porcine liver with four-electrode arrays

PURPOSE

To prospectively determine optimal parameters with which to achieve defined large target zones of coagulation by using irreversible electroporation (IRE) with four-electrode arrays and the time needed to achieve this treatment effect in an in vivo animal model.

MATERIALS AND METHODS

This study was approved by the animal care and use committee. Ultrasonography (US)-guided IRE ablation (n = 90) was performed in vivo in 69 pig livers with an array of four electrodes (18 gauge) and an electroporation generator. Cardiac-gated 100-µsec IRE pulses were applied sequentially between the six sets of electrode pairs at 2250-3000 V. Multiple algorithms of energy deposition and electrode configuration were studied, including interelectrode spacing (1.5-2.5 cm), number of IRE pulses applied consecutively to each electrode pair (10, 20, 50, and 100), and number of times per cycle each electrode pair was activated (one to 10). Resultant zones of treatment were measured with US 1.5-3 hours after IRE and confirmed at gross and histopathologic examination. Data and ablation times were compared to determine the optimal algorithms with which to achieve 4-7-cm areas of treatment effect in the shortest time possible. In addition, the IRE current applied was correlated with ablation size. Data were analyzed by using analysis of variance with multiple comparisons, t tests, or nonparametric statistics.

RESULTS

For 2.5-cm spacing, ablation diameter was increased by increasing either the overall time of energy application or the number of cycles of 20 pulses (P < .01 for both). IRE application of less than four cycles (or continuous IRE application of 100 pulses) did not result in contiguous ablation. However, sequentially increasing the number of cycles of IRE from four to 10 increased both the electrical current applied (from 14.4 A ± 0.4 to 17.6 A ± 0.7, P = .0004) and ablation diameter (from 5.6 cm ± 0.3 to 6.6 cm ± 0.3, P = .001). Although division of application into cycles did not alter coagulation at 2.0- and 1.5-cm spacing, application of energy to diagonal electrode pairs increased coagulation. Thus, one 100-pulse cycle (11.0 minutes ± 1.4) produced 4.8 cm ± 0.3 of ablation for 2.0-cm spacing with diagonal pairs but only 4.1 cm ± 0.3 of ablation without diagonal pairs (7.5 minutes ± 1.0, P < .03 for both).

CONCLUSION

With four-electrode arrays, IRE can create large contiguous zones of treatment effect in clinically acceptable ablation times; parameters can be tailored to achieve a wide range of ablation sizes. Cyclical deposition of IRE application is beneficial, particularly for larger interprobe spacing, most likely owing to alterations of electrical conductivity that occur after successive applications of IRE energy.

Image-guided thermal ablation of tumors increases the plasma level of interleukin-6 and interleukin-10

PURPOSE

To identify changes in plasma cytokine levels after image-guided thermal ablation of human tumors and to identify the factors that independently predict changes in plasma cytokine levels.

MATERIALS AND METHODS

Whole-blood samples were collected from 36 patients at three time points: before ablation, after ablation (within 48 hours), and at follow-up (1-5 weeks after ablation). Plasma levels of interleukin (IL)-1α, IL-2, IL-6, IL-10, and tumor necrosis factor (TNF)-α were measured using a multiplex immunoassay. Univariate and multivariate analyses were performed using cytokine level as the dependent variable and sample collection, time, age, sex, primary diagnosis, metastatic status, ablation site, and ablation type as the independent variables.

RESULTS

There was a significant increase in the plasma level of IL-6 after ablation compared with before ablation (9.6-fold ± 31-fold, P<.002). IL-10 also showed a significant increase after ablation (1.9-fold ± 2.8-fold, P<.02). Plasma levels of IL-1α, IL-2, and TNF-α were not significantly changed after ablation. Cryoablation resulted in the largest change in IL-6 level (>54-fold), whereas radiofrequency ablation and microwave ablation showed 3.6-fold and 3.4-fold changes, respectively. Ablation of melanomas showed the largest change in IL-6 48 hours after ablation (92×), followed by ablation of kidney (26×), liver (8×), and lung (6×) cancers. Multivariate analysis revealed that ablation type (P<.0003) and primary diagnosis (P<.03) were independent predictors of changes to IL-6 after ablation. Age was the only independent predictor of IL-10 levels after ablation (P< .019).

CONCLUSIONS

Image-guided thermal ablation of tumors increases plasma levels of IL-6 and IL-10, without increasing plasma levels of IL-1α, IL-2, or TNF-α.

SonoKnife for ablation of neck tissue: in vivo verification of a computer layered medium model

PURPOSE

This study aimed to determine which treatment parameters of the SonoKnife device can be used to safely and effectively perform non-invasive thermal ablation of subcutaneous tissue.

METHODS

A three-dimensional computational layered medium model was constructed to simulate thermal ablation treatment of the SonoKnife device. The acoustic and thermal fields were calculated with the Fast Object-Oriented C++ Ultrasound-Simulator software and a finite difference code, respectively. Subcutaneous tissue was represented as layers of skin, fat and muscle. The simulations were conducted for ultrasound frequencies of 1 or 3.5 MHz. The thermal dose model was used to predict the size and location of the ablated regions. The computer simulations were verified by using the SonoKnife to perform subcutaneous ablations in the neck area of healthy pigs, in vivo. Triphenyltetrazolium chloride viability stain was used to differentiate viable tissue from ablated regions ex vivo.

RESULTS

The simulations for the layered medium model suggest that operating the SonoKnife at frequency of 1 MHz is more effective and safer than 3.5 MHz providing skin cooling is applied prior to ablation. These predictions were in agreement with the results observed in the animal studies. The required sonication time for ablation increased from 50 to 300 s by using 1 MHz.

CONCLUSION

Our modelling and animal studies suggest that 1 MHz with pretreatment skin cooling are the optimal settings to operate the SonoKnife to safely and effectively perform subcutaneous thermal ablation of porcine skin. More work is needed to optimise skin cooling and define the optimal sonication time.

Efficacy of microwave versus radiofrequency ablation for treatment of small hepatocellular carcinoma: experimental and clinical studies

OBJECTIVE

To prospectively compare microwave (MW) ablation using a modified internal cooled-shaft antenna with radiofrequency (RF) ablation in in vivo porcine liver and in patients with small hepatocellular carcinoma (sHCC).

METHODS

In an animal study, MW and RF ablations using a cooled-shaft antenna or internally cooled electrode were performed in in vivo porcine liver. Coagulation diameters of both ablations were compared. For clinical study, 42 patients with sHCC were treated with MW or RF ablation. Complete ablation (CA) and local tumour progression (LTP) were compared.

RESULTS

MW ablation produced significantly larger ablation zones than RF ablation in both porcine liver and sHCC with an ablated volume of 33.3 ± 15.6 cm(3) vs. 18.9 ± 9.1 cm(3) and 109.3 ± 58.3 cm(3) vs. 48.7 ± 30.5 cm(3), respectively. The CA rate was 95.5 % (21/22) for MW ablation and 95.0 % (19/20) for RF ablation. In a 5.1-month follow-up, the LTP rate was 18.2 % (4/22) in the MW ablation group and 15.0 % (3/20) in the RF ablation group.

CONCLUSION

MW ablation using a modified cooled-shaft antenna produces a larger ablation zone than RF ablation, with an efficacy similar to RF ablation in local tumour control. MW ablation is a safe and promising treatment of sHCC.

Development of ti-coated ferromagnetic needle, adaptable for ablation cancer therapy by high-frequency induction heating

To develop a novel ablation therapy for human solid cancer, the heating properties of a ferromagnetic carbon steel rod and a prototype Ti-coated needle using this carbon steel rod, were investigated in several high-frequency outputs at 300 kHz. In the former, the heating property was drastically different among the three inclination angles (θ = 0°, 45° and 90°) relative to the magnetic flux direction as a result of the shape magnetic anisotropy. However, the effect of the inclination angles was completely eliminated in the latter. It is considered that the complete non-oriented heating property relative to the magnetic flux direction allows the precise control of the ablation temperature during minimally invasive thermotherapy without a lead-wire connected to a fiber-optic thermometer. This newly designed Ti-coated device will be suitable for clinical use combined with its superior biocompatibility for ablation treatments using high-frequency induction heating.

A case of hemocholecyst associated with hemobilia following radiofrequency ablation therapy for hepatocellular carcinoma

Radiofrequency ablation (RFA) is performed as an alternative to surgical resection for primary or secondary liver malignancies. Although RFA can be performed safely in most patients, early and late complications related to mechanical or thermal damage occur in 8-9.5% cases. Hemocholecyst, which refers to hemorrhage of the gallbladder, has been reported with primary gallbladder disease or as a secondary event associated with hemobilia. Hemobilia, defined as hemorrhage in the biliary tract and most commonly associated with accidental or iatrogenic trauma, is a rare complication of RFA. Here we report a case of hemocholecyst associated with hemobilia after RFA for hepatocellular carcinoma that was successfully managed by laparoscopic cholecystectomy.

SonoKnife: feasibility of a line-focused ultrasound device for thermal ablation therapy

PURPOSE

To evaluate the feasibility of line-focused ultrasound for thermal ablation of superficially located tumors.

METHODS

A SonoKnife is a cylindrical-section ultrasound transducer designed to radiate from its concave surface. This geometry generates a line-focus or acoustic edge. The motivation for this approach was the noninvasive thermal ablation of advanced head and neck tumors and positive neck nodes in reasonable treatment times. Line-focusing may offer advantages over the common point-focusing of spherically curved radiators such as faster coverage of a target volume by scanning of the acoustic edge. In this paper, The authors report studies using numerical models and phantom and ex vivo experiments using a SonoKnife prototype.

RESULTS

Acoustic edges were generated by cylindrical-section single-element ultrasound transducers numerically, and by the prototype experimentally. Numerically, simulations were performed to characterize the acoustic edge for basic design parameters: transducer dimensions, line-focus depth, frequency, and coupling thickness. The dimensions of the acoustic edge as a function of these parameters were determined. In addition, a step-scanning simulation produced a large thermal lesion in a reasonable treatment time. Experimentally, pressure distributions measured in degassed water agreed well with acoustic simulations, and sonication experiments in gel phantoms and ex vivo porcine liver samples produced lesions similar to those predicted with acoustic and thermal models.

CONCLUSIONS

Results support the feasibility of noninvasive thermal ablation with a SonoKnife.

Targeted magnetic hyperthermia

Many nanotechnologies, which enable unique approaches to treat cancer, have been developed based upon non-toxic organic and inorganic materials to improve current cancer treatments. The use of inorganic materials to form magnetic nanoparticles for hyperthermia therapy is of great interest for localized treatment of cancers without effecting adjacent healthy tissue. Extensive clinical trials have begun using magnetic hyperthermia in animal models. The purpose of this article is to address different factors that affect targeting, heating and biodistribution to safely control the therapeutic efficacy of targeted magnetic hyperthermia. This method involves accumulation of magnetic nanoparticles at a tumor site and then manipulating the magnetic properties of the nanoparticles to heat the targeted tissues.

Intention-to-treat analysis of liver transplantation for hepatocellular carcinoma: living versus deceased donor transplantation

For patients who have cirrhosis with hepatocellular carcinoma (HCC), living donor liver transplantation (LDLT) reduces waiting time and dropout rates. We performed a comparative intention-to-treat analysis of recurrence rates and survival outcomes after LDLT and deceased donor liver transplantation (DDLT) in HCC patients. Our study included 183 consecutive patients with HCC who were listed for liver transplantation over a 9-year period at our institution. Tumor recurrence was the primary endpoint. At listing, patient and tumor characteristics were comparable in the two groups (LDLT, n = 36; DDLT, n = 147). Twenty-seven (18.4%) patients dropped out, all from the DDLT waiting list, mainly due to tumor progression (19/27 [70%] patients). The mean waiting time was shorter in the LDLT group (2.6 months versus 7.9 months; P = 0.001). The recurrence rates in the two groups were similar (12.9% and 12.7%, P = 0.78), and there was a trend toward a longer time to recurrence after LDLT (38 ± 27 months versus 16 ± 13 months, P = 0.06). Tumors exceeding the University of California, San Francisco (UCSF) criteria, tumor grade, and microvascular invasion were independent predictive factors for recurrence. On an intention-to-treat basis, the overall survival (OS) in the two groups was comparable. Patients beyond the Milan and UCSF criteria showed a trend toward worse outcomes with LDLT compared with DDLT (P = 0.06).

CONCLUSION

The recurrence and survival outcomes after LDLT and DDLT were comparable on an intent-to-treat analysis. Shorter waiting time preventing dropouts is an additional advantage with LDLT. LDLT for HCC patients beyond validated criteria should be proposed with caution.

In vivo microwave-induced porcine kidney thermoablation: results and perspectives from a pilot study of a new probe

OBJECTIVE

To test the in vivo effects (toxicity, completeness of necrosis, dimensions of the lesion) of microwave thermoablation on porcine kidneys, using the Amica Probe v3 (Hospital Service SpA, Aprilia, Italy), in a refrigerated 17-G microwave applicator, that can be used to induce a spherical necrotic area.

PATIENTS AND METHODS

Six pigs were used; each kidney was treated, with no kidney pedicle clamping, by microwave thermoablation at least in three different zones with different exposure times and power, during open surgery. Twelve kidneys had 32 microwave thermoablations overall. The kidneys were then surgically removed, and necrotic lesions measured and evaluated microscopically. The sphericity index (SI) was also calculated to evaluate lesion reproducibility. Areas of renal tissue that were missed were then microscopically evaluated by NADH in vivo staining.

RESULTS

In all, 32 thermoablations were applied; the mean (sd) lesion diameter ranged from 1.2 (0.3) to 4.2 (0.1) cm and changed in relation to both power and time of exposure. The 50-W power particularly induced necrotic renal lesions ranging from 1.9 (0.2) to 4.2 (0.1) cm as a function of the time of exposure and the optimal SI (1.04). Pathological evaluation showed no skipped areas in the context of the lesion, or healthy kidney tissue damage close to necrotic lesions.

CONCLUSIONS

Thermoablation with the Amica probe is safe and showed excellent in vivo effects in this porcine model. Increasing the exposure time at 50 W power could be a useful percutaneous minimally invasive treatment for small solid masses (<4.2 cm), avoiding the risk of missing tumour areas or kidney parenchymal damage from microwave treatment.

Right thoracic paravertebral anaesthesia for percutaneous radiofrequency ablation of liver tumours

OBJECTIVES

Percutaneous radiofrequency ablation (PRFA) of liver tumours performed under local anaesthesia and intravenous sedation can cause severe pain to patients. This prospective study evaluated the efficacy of a right thoracic paravertebral block (TPVB) for anaesthesia and analgesia during PRFA of liver tumours.

METHODS

20 patients, aged 44-74 years, with liver malignancies received a multiple injection TPVB at the T6-10 levels 30 min before the PRFA. An intravenous infusion of propofol (3-5 mg kg(-1) h(-1)) was administered to patients who requested to be sedated and intravenous fentanyl (25 µg bolus) was administered as rescue analgesia. Pain during the TPVB and PRFA was assessed using a numerical rating scale (NRS; 0, no pain; 10, worst imaginable pain). Patients were also assessed for residual pain and analgesic consumption during the 24 h after the intervention.

RESULTS

The TPVB was well tolerated and produced ipsilateral sensory anaesthesia with satisfactory spread (median (range); 8 (6-11) dermatomes). The PRFA procedure caused mild pain (mean (standard deviation, SD); NRS 1.4 (1.9)) during the insertion of the ablation needle and the peak pain intensity during the therapeutic burn was moderate (mean (SD); NRS 5.0 (3.3)) in severity. During the 24 h after the PRFA, patients reported minimal pain and consumed very few analgesics. The mean (SD) satisfaction score (0, totally dissatisfied; 10, very satisfied) of the patients was 8.9 (1.1) and that of the radiologists was 8.8 (1.4).

CONCLUSION

A right TPVB is safe and effective for anaesthesia and analgesia during PRFA of malignant liver tumours.

Selecting treatment for hepatocellular carcinoma based on the results of hepatic resection and local ablation therapy

BACKGROUND

First-line treatment for <or=3 hepatocellular carcinomas (HCCs) <or=3 cm in size remains controversial. The superiority of survival benefit needs to be clarified between these modalities for such lesions.

METHODS

We examined post-treatment survival of 144 consecutive HCC patients who underwent hepatectomy and of 56 consecutive HCC patients who underwent thermal ablation therapy limited to the HCC (<or=3 cm, <or=3 lesions).

RESULTS

Pretreatment liver function was significantly worse and prevalence of Child-Pugh classification B/C was significantly higher in the ablation group compared to the hepatectomy group. Prevalence of tumor recurrence after treatment did not differ significantly between groups, irrespective of solitary or multiple HCC. In solitary HCC, overall survival rates in both groups did not differ significantly. Even in Child-Pugh B patients, survival was not significantly different between hepatectomy and ablation. In HCC with 2-3 lesions <or=3 cm, overall survival was significantly longer with hepatectomy than with ablation and mean survival periods in the hepatectomy and ablation groups were 4.5 and 1.2 years, respectively.

CONCLUSION

In cases of multiple small HCCs, hepatic resection is recommended over local ablation therapy as the first-line treatment in cases where liver function has been preserved.

Establishing Nd:YAG laser-based left lateral liver resection: comparison of open, laparoscopic, and hand-assisted approach in a porcine Model

INTRODUCTION

Aim of this study was to assess the feasibility and safety of a 1064 nm Nd:YAG laser for left lateral liver resection in a porcine model. Laparoscopy and hand-assisted laparoscopic surgery were evaluated and compared with conventional open surgery.

METHODS

Animals were randomized for open, hand assisted, and laparoscopic left lateral liver lobe resection. Primary endpoints were intraoperative blood loss, dissection time, laboratory changes, and abdominal wall adhesions. In addition intraoperative cardiopulmonary data, postoperative clinical parameters, and necropsy findings were analyzed.

RESULTS

Liver resection was successful in all animals without intraoperative or postoperative mortality. Laparoscopic dissection time was significantly increased. Average blood loss was 340 mL for open surgery and 320 mL for hand-assisted surgery. Blood loss during laparoscopy was significantly smaller with a mean of 180 mL. Postmortem findings revealed extensive adhesions for open surgery whereas hand assisted and laparoscopic animals showed limited adhesions in the upper abdomen.

CONCLUSIONS

Nd:YAG laser-based liver resection is a potentially safe and feasible technique. The minimal access approaches show comparable results to the open technique with reduced abdominal trauma and less adhesions. Laparoscopy was more time consuming but showed reduced blood loss compared with both other groups.

Prediction of progression-free survival in patients presenting with hepatocellular carcinoma within the Milan criteria

Transplantation is the treatment of choice for hepatocellular carcinoma (HCC) meeting the Milan criteria. HCC and chronic liver diseases have distinct natural histories for which an equitable transplant policy must account. We enrolled and prospectively followed at a single center 206 consecutive HCC patients that presented within the Milan criteria. Patients were treated per the Barcelona Clinic Liver Cancer (BCLC) algorithm; 95% received resection, ablation, or transarterial chemoembolization. The median follow-up was 16 months. Progression occurred in 84 patients, and 8 patients died. Risk factors for the time to disease progression (death or progression beyond T2) were analyzed in 170 patients with a complete data set. Risk factors with the strongest relationship to progression included tumor diameter and tumor persistence/recurrence after local therapy (hazard ratios of 1.51 and 2.75, respectively, when transplanted patients were censored at the time of transplantation and hazard ratios of 1.53 and 3.66, respectively, when transplantation was counted as an event; P < or = 0.0001). To evaluate the current Model for End-Stage Liver Disease (MELD) exception, we compared the expected progression rate (PR) with our observed PR in 133 stage T2 patients. The current policy resulted in a large overestimation of the PR for T2 HCC and an unsatisfactory performance [Harrell's concordance index (C index) = 0.60, transplant censored; C index = 0.55, transplant as progression]. Risk factors for progression that were identified by univariate analysis were considered for multivariate analysis. With these risk factors and the patients' natural MELD scores, an adjusted model applicable to organ allocation was generated, and this decreased the discrepancy between the expected and observed PRs (C index = 0.66, transplant censored; C index = 0.69, transplant as progression). In conclusion, the current MELD exception largely overestimates progression in T2 patients treated according to the BCLC guidelines. The tumor response to resective or ablative treatment can predict tumor progression beyond the Milan criteria, and it should be taken into account in models designed to prioritize organ allocation.

Dead or alive? Autofluorescence distinguishes heat-fixed from viable cells

PURPOSE

A proof-of-concept study to evaluate a new autofluorescence method to differentiate necrotic thermally fixed cells from viable tissue following thermal ablation.

METHODS

A conductive interstitial thermal therapy (CITT) device was used to ablate swine mammary tissue and rabbit VX-2 carcinomas in vivo. The ablated regions and 10-mm margins were resected 24 h following treatment, embedded in HistOmer and sectioned at 3 mm. The fresh sections were evaluated for gross viability with triphenyl tetrazolium chloride, 1 h post-resection. Representative non-viable and viable areas were then processed and embedded into paraffin, and sectioned at 5 microm. Standard H&E staining and proliferating cell nuclear antigen (PCNA) immunohistochemistry were compared against autofluorescence intensity, at 488-nm wavelength, for cellular viability.

RESULTS

Heat-fixed cells in non-viable regions exhibit increased autofluorescence intensity compared to viable tissue (area under receiver operating characteristics (ROC) curve = 0.96; Mann-Whitney P < 0.0001). An autofluorescence intensity-based classification rule achieved 92% sensitivity with 100% specificity for distinguishing non-viable from viable samples. In contrast, PCNA staining did not reliably distinguish heat-fixed, dead cells from viable cells.

CONCLUSIONS

Examination of H&E-stained sections using autofluorescence intensity-based classification is a reliable and readily available method to accurately identify heat-fixed cells in ablated surgical margins.

The efficacy and safety of percutaneous microwave coagulation by a new microwave delivery system in large hepatocellular carcinomas: four case studies

PURPOSE

To demonstrate the efficacy and safety of percutaneous microwave coagulation treatment (PMCT) by a new microwave delivery system (Forsea Microwave) in large hepatocellular carcinomas (HCC) (> or =5 cm).

MATERIALS AND METHODS

Four patients with 4 HCC lesions measuring > or =6 cm in the greatest dimension underwent PMCT by means of the Forsea Microwave microwave delivery system. Final therapeutic efficacy was evaluated with dynamic computer tomography (CT) scans performed within one month after PMCT. During and after PMCT, patients' complaints and any abnormal physical signs were recorded for safety assay. CT or ultrasound scan (US) performed immediately after the treatment was used to detect acute complications related to the treatment. Repeated dynamic CT scans were performed every three to four months thereafter to detect local disease recurrence and/or other recurrences.

RESULTS

Three of these patients achieved a complete ablation of the cancer nodules (two patients with two treatment sessions and one patient with three treatment sessions). One of these patients obtained a complete ablation of the cancer nodule with two treatment sessions except the lesion of portal vein tumour thrombus (PVTT). No obvious symptomatic complication was observed except abdominal pain during and after the treatment in two of these patients. All the patients remained asymptomatic and no recurrent tumour was observed during their follow-up (1-19 months).

CONCLUSIONS

PMCT by the Forsea Microwave microwave delivery system could offer a satisfactory therapeutic effect and is applicable to the treatment of large HCC.

Major complications after radiofrequency ablation for liver tumors: Analysis of 255 patients

AIM: To investigate the major complications after radiofrequency ablation (RFA) for the treatment of liver tumors and analyze possible risk factors that precipitate these complications.

METHODS: From March 2001 to April 2008, 255 patients with liver tumors (205 male, 50 female; age range, 18-89 years; mean age, 56.0 years) who received RFA were enrolled in this study. Of these patients, 212 had hepatocellular carcinoma, 39 had metastatic liver tumors and four had cholangiocellular carcinoma. One hundred and forty eight patients had a single tumor, and 107 had multiple tumors. Maximum diameter of the tumors ranged 1.3-20 cm (mean, 5.1 cm). All patients were treated with a cooled-tip perfusion electrode attached to a radiofrequency generator (Radionics, Burlington, MA, USA). RFA was performed via the percutaneous approach (n = 257), laparoscopy (n = 7), or open surgical treatment (n = 86). The major complications related to RFA were recorded. The resultant data were analyzed to determine risk factors associated these complications.

RESULTS: Among the 255 patients, 425 liver tumors were treated and 350 RFA sessions were performed. Thirty-seven (10%) major complications were observed which included 13 cases of liver failure, 10 cases of hydrothorax requiring drainage, three cases of tumor seeding, one case of upper gastrointestinal bleeding, one case of intrahepatic abscess, one case of bile duct injury, one case of cardiac arrest, and five cases of hyperglycemia. Seven patients had more than two complications. Liver failure was the most severe complication and was associated with the highest mortality. Eleven patients died due to worsening liver decompensation. Child-Pugh classification (P = 0.001) and choice of approach (P = 0.045) were related to post-treatment liver failure, whereas patient age, tumor size and number were not significant factors precipitating this complication.

CONCLUSION: RFA can be accepted as a relatively safe procedure for the treatment of liver tumors. However, attention should be paid to possible complications even though the incidences of these complications are rare. Careful patient selection and the best approach choice (percutaneous, laparoscopy, or laparotomy) will help to minimize the incidence and morbidity rate of complications which occur after RFA.

Meta-analysis of percutaneous radiofrequency ablation versus ethanol injection in hepatocellular carcinoma

BACKGROUND

Percutaneous radiofrequency ablation (RFA) has gained popularity in the treatment of hepatocellular carcinoma (HCC). However, its role versus other conventional minimally invasive therapies is still a matter of debate. The purpose of this work is to analyse the efficacy and safety of RFA versus that of ethanol injection (PEI), the percutaneous standard approach to treat nonsurgical HCC.

METHODS

Systematic review and meta-analysis of randomised or quasi-randomised controlled trials published up to August 2008 in PubMed, ISI Web of Science and The Cochrane Library. Overall survival, local recurrence rate and adverse effects were considered as primary outcomes. Studies were critically appraised and estimates of effect were calculated according to the random-effects model. Inconsistency across studies was evaluated using the I2 statistic. Sensitivity analyses were conducted to explore statistical heterogeneity.

RESULTS

Six studies were eligible. The studies reported data on 396 patients treated by RFA and 391 treated by PEI. In general, subjects were in Child-Pugh class A (74%) and had unresectable HCC (mean size 2.5 cm). Mean follow-up was 25 +/- 11 months. The survival rate showed a significant benefit for RFA over PEI at one, two, three and four years. The advantage in survival increased with time with Relative Risk values of: 1.28 (95%CI:1.12-1.45) and 1.24 (95%CI:1.05-1.48) for RFA versus PEI at 3- and 4-years respectively. Likewise, RFA achieved significantly lower rates of local recurrence (RR: 0.37, 95%CI: 0.23-0.59). The overall rate of adverse events was higher with RFA (RR:2.55, 95%CI: 1.8-3.6) yet no significant differences were found concerning major complications (RR:1.85, 95%CI: 0.68-5.01). There was not enough evidence supporting a better cost-effectiveness ratio for RFA compared to PEI.

CONCLUSION

Available evidence from adequate quality controlled studies support the superiority of RFA versus PEI, in terms of better survival and local control of the disease, for the treatment of patients with relatively preserved liver function and early-stage non-surgical HCC. However, the higher rate of adverse events displayed is something that will have to be tested with appropriate weighting of the possible benefits in each individual case. Overall cost-effectiveness of RFA needs further evaluation.

Role of Sonazoid-enhanced three-dimensional ultrasonography in the evaluation of percutaneous radiofrequency ablation of hepatocellular carcinoma

OBJECTIVE

We investigated contrast-enhanced three-dimensional ultrasonography (CE 3D US) with contrast agent Sonazoid for evaluating the effect of percutaneous radiofrequency (RF) ablation of hepatocellular carcinomas (HCCs).

METHODS

63 HCCs were treated by US-guided percutaneous RF ablation. CE 3D US after bolus injection of 0.2 mL of Sonazoid was performed 5-7 days before and 1 day after RF ablation. CE 3D computed tomography (CT) was performed 5-7 days before and 1 month after the ablation, and during the follow-up period. Multiplanar images in three orthogonal planes and US/CT angiograms were reconstructed on both modalities. Two blinded observers reviewed the images on both modalities to evaluate the ablation effects.

RESULTS

After RF ablation, the evaluation on CE 3D US and that on CE 3D CT achieved concordance in 61 lesions. Among them, 59 lesions were detected with the absence of tumor vessels and tumor enhancement and evaluated as adequate ablation, and the remaining two lesions were detected with residual tumors. The kappa value for agreement between the findings on the two modalities was 0.65. When 1-month CE 3D CT scans were used as reference standard, the sensitivity, specificity, and accuracy of 1-day CE 3D US for detecting adequate ablation were 97%, 100%, and 97%, respectively.

CONCLUSION

By demonstrating the ablated areas and residual tumors in three dimensions, CE 3D US with Sonazoid was shown to be useful for evaluating the effect of RF ablation of HCCs, and there was good concordance with the results obtained by CE 3D CT.