Thermal Ablation Of Liver Cancer Research Articles

Complications Associated with Image-Guided Percutaneous Thermal Ablation of Liver Tumors

AbstractImage-guided thermal ablation of liver cancer is a well-established treatment for patients with primary or secondary liver tumors. While the safety profile for liver ablations is high, several procedure-related complications can occur. An awareness of the potential complications, their recognition, and management are essential for the interventionist who performs liver ablation. This review will describe some of the most frequently encountered complications associated with image-guided thermal ablation of hepatic malignancies.

Contrast-enhanced Ultrasound for Evaluation of Active Needle Tract Bleeding during Thermal Ablation of Liver Cancer

Contrast-enhanced Ultrasound for Evaluation of Active Needle Tract Bleeding during Thermal Ablation of Liver Cancer

A comparison of gastric gas volumes measured by computed tomography after high‐flow nasal oxygen therapy or conventional facemask ventilation*

High-flow nasal oxygen therapy is increasingly used to improve peri-intubation oxygenation. However, it is unknown whether it may cause or exacerbate insufflation of gas into the stomach. High-flow nasal oxygen therapy is now standard practice in our hospital for adult patients undergoing percutaneous thermal ablation of liver cancer under general anaesthesia with tracheal intubation. We compared gastric gas volumes measured from computed tomography images that had been acquired immediately after intubation in two series of patients: 50 received peri-intubation high-flow nasal oxygen therapy and another 50 received conventional facemask pre-oxygenation and ventilation before intubation and before high-flow nasal oxygen therapy became standard practice in our unit. Median (IQR [range]) gastric gas volume was 24.0 (14.2-59.9 [3-167]) cm3 in the high-flow nasal oxygen therapy group and 23.8 (12.6-38.8 [0-185]) cm3 in the facemask group. There was no difference between the two groups in the volume of gastric gas measured by computed tomography imaging (Mann-Whitney U-test, U=1136, p=0.432, n1 =n2 =50). Our results demonstrate that a small volume of gastric gas is commonly present after induction of anaesthesia, but that the use of peri-intubation high-flow nasal oxygen therapy for pre-oxygenation and during apnoea does not increase this volume compared with conventional facemask pre-oxygenation and ventilation. This is clinically relevant, as high-flow nasal oxygen therapy is increasingly being used in a peri-intubation context and in patients at higher risk of aspiration.

The Learning Curve for Thermal Ablation of Liver Cancers: 4,363-Session Experience for a Single Central in 18 Years.

This study aimed to explore the special efforts required to achieve proficiency in performing thermal ablation of liver cancers, including tumors in difficult locations, and clarify the effects of handing-down teaching on the corresponding process. Major complications of patients receiving percutaneous thermal ablation of liver cancer were analyzed. Polynomial fitting was used to describe the connection between major complication rates and special experience. Learning curve of major complications was plotted both for the whole group and for each operator, respectively. Tumors in difficult locations were further studied. A total of 4,363 thermal ablation sessions were included in this study. 143 of 4,363 patients had major complications, corresponding to an incidence rate of 3.27%. 806 thermal ablation sessions were performed for tumors in difficult locations. The major complication rate of these sessions is 6.33%. According to the trend of the learning curve of the 4363 patients, the experience of the whole group can be classified into five stages, that is, the high-risk, relatively stable, unstable, proficient and stable periods. A learning curve for an individual operator can be classified into the high-risk, proficient and stable periods. The major complication rates for the chronologically first, second and third operator of the group are 3.23, 3.35, and 3.31%, respectively. The special experience needed to bypass the first stage corresponds to 410, 510, and 440 sessions, the second stage, 1850, 850, and 870 sessions, by the three operators, respectively. The major complication rates for the tumors in difficult locations for the first, second and third operator were 7.04, 5.53, and 5.98%, respectively. For the tumors in difficult locations, the special experience needed to bypass the first stage corresponds to 150, 130, and 140 sessions, the second stage, 290, 175, and 185 sessions, by the three operators, respectively. In conclusion, the learning process of an operator percutaneous thermal ablation for liver cancer can be classified into three stages. The major complication rate for tumors in difficult locations were higher than that for all tumors. Handing-down teaching can make an operator arrive at the third stage earlier but not the second stage.

Early Identification of Residual Tumors following Microwave Ablation Using Contrast-Enhanced Ultrasonography in a Rabbit VX2 Liver Cancer Model.

Objective It is difficult to evaluate the ablation effect immediately after thermal ablation of liver cancer by clinical imaging methods, due to the immediate formation of an annular inflammatory reaction band (IRB). This study is aimed at exploring the early identification indicators of the IRB and residual tumor postmicrowave ablation (MVA) using contrast-enhanced ultrasonography (CEUS). Methods MVA was used to inactivate part of the tumor nodules in rabbit VX2 liver cancer models, leading to the coexistence of the IRB with residual tumors. Quantitative analysis of the perfusion parameters of the tumor and ablation zone was performed using CEUS, followed by liver biopsy and VEGFR-2 immunohistochemical staining. Results All rabbits successfully tolerated VX2 tumor inoculation and MVA operation. No statistically significant difference existed between the IRB vs. residual tumors, the IRB vs. junctional areas, and residual tumors postablation vs. VX2 tumors before ablation in regional blood volume, blood velocity, and blood flow estimated by parameters A, k, and A∗k of CEUS quantitative analysis. There was a statistically significant difference between the IRB and normal liver parenchyma in regional blood velocity and blood flow (p = 0.005 and p = 0.023, respectively). Normal liver parenchyma showed nonspecific VEGFR-2 staining, while VX2 tumor before ablation and residual tumor after ablation both showed positive VEGFR-2 staining; the necrosis zone showed negative staining by VEGFR-2 immunohistochemical staining. Conclusion MVA had no significant effect on the residual tumor hemodynamics. The blood flow in the IRB increased significantly as compared to normal liver parenchyma, resembling tumor hemodynamic patterns. CEUS can detect residual tumors immediately postablation only when they protrude from the annular-shaped IRB. In addition, VEGFR-2 targeted CEUS may have a great potential for detecting residual tumor after thermal ablation of hepatocellular carcinoma.

Ex vivo thermal ablation monitoring using three-dimensional ultrasound echo decorrelation imaging

Echo decorrelation imaging is a method for quantitatively mapping transient heat-induced changes in pulse-echo ultrasound images. For clinical thermal ablation of liver cancer using radiofrequency or microwave ablation (RFA or MWA), real-time three-dimensional (3D) echo decorrelation imaging is necessary because the entire tumor, with typical diameter 2–5 cm, is ablated at once. We present a method for constructing 3D echo decorrelation maps during radiofrequency ablation (RFA) in ex vivo bovine liver using beamformed in-phase and quadrature (IQ) echo acquired from a Siemens Acuson SC2000 scanner and 4Z1c matrix array. To directly compare echo decorrelation images to the desired outcome of tissue ablation, 3D echo decorrelation images are compared to volumetric reconstructions of the thermal ablation zone, obtained from optical scans of regularly spaced tissue sections. Capability of echo decorrelation as a predictor of local ablation is assessed using receiver operator characteristic curve analysis. Similar to previous studies of two-dimensional echo decorrelation imaging, good correspondence is seen between 3D echo decorrelation images and ablated tissue histology.

Analysis for complications of biliary tract after percutaneous thermal ablation for liver cancer

Objective To investigate the risk factors of biliary tract complications in patients with liver cancer after thermal ablation and the prevention methods. Methods One thousand seven hundred and ninety-seven patients with liver cancer underwent percutaneous thermal ablation were enrolled in this retrospective study. According to the relative position of the tumor and biliary tract, patients were classified into 4 groups: with the tumor close to the first branch (group Ⅰ), the second branch (group Ⅱ), the third branch of bile duct (group Ⅲ) and far away from the biliary tract (group Ⅳ). The tumor response and complications, especially biliary tract complications after ablation therapy of subgroups were analyzed. Results A total of 2 356 sessions were performed in 1 797 patients with 3 200 lesions. The local progression rates of the tumors close to and far away from biliary were 10.0% and 8.2% (P=0.080) and the rate of complete ablation were 96.5% and 97.2%(P=0.298), respectively.Fourteen patients suffered from major biliary complications after thermal ablation. Biliary complication incidences of the patients with the tumor close to the first, the second biliary tract were 6.5% and 2.9% respectively, which were all higher than those of the patients with the tumor close to the third(0.3%) and far away from biliary duct(0.2%). Conclusions Percutaneous thermal ablation is an efficient and safe method in the treatment of tumors close to biliary tract and with a low incidence of major biliary complications. Patients with a tumor close to the large branch of biliary duct were at high risk of complications. Those tumors, therefore, should be ablated with assisting methods and extra care. Key words: Ultrasonography; Liver neoplasms; Thermal ablation; Complications; Biliary tract

Incidence and Risk Factors for Liver Abscess After Thermal Ablation of Liver Neoplasm.

BackgroundRadiofrequency ablation (RFA) and microwave ablation (MWA) are the most frequently used thermal ablation methods for the treatment of liver cancer. Liver abscess is a common and severe complication of thermal ablation treatment.ObjectivesThe objective of this study was to determine the incidence and risk factors of liver abscess formation after thermal ablation of liver cancer.Materials and MethodsThe clinical data of 423 patients who underwent 691 thermal ablation procedures for liver cancer were collected in order to retrospectively analyze the basic characteristics, incidence, and risk factors associated with liver abscess formation. Patients with multiple risk factors for liver abscess formation were enrolled in a risk factor group, and patients with no risk factors were enrolled in a control group. The chi-square test and multiple logistic regression analysis were used to analyze the relationship between the occurrence of liver abscesses and potential risk factors.ResultsTwo hundred and eight patients underwent 385 RFA procedures, and 185 patients underwent 306 MWA procedures. The total incidence of liver abscesses was 1.7%, while the rates in the RFA group (1.8%) and MWA groups (1.6%) were similar (P > 0.05). The rates of liver abscesses in patients who had child-pugh class B and class C cirrhosis (P = 0.0486), biliary tract disease (P = 0.0305), diabetes mellitus (P = 0.0344), and porta hepatis tumors (P = 0.0123) were 4.0%, 6.7%, 6.5%, and 13.0%, respectively. There was a statistically significant difference between these four groups and the control group (all P < 0.05). The incidence of liver abscesses in the combined ablation and percutaneous ethanol injection (PEI) group (P = 0.0026) was significantly lower than that of the ablation group (P < 0.05).ConclusionsThe incidence of liver abscesses after liver cancer thermal ablation is low. Child-Pugh Class B and Class C cirrhosis, biliary tract disease, diabetes mellitus, and porta hepatis tumors are four significant risk factors. Combined ablation and PEI reduces the rate of liver abscesses.

Technology for Radiofrequency Thermal Ablation of Liver Tumors.

In this review the usefulness of percutaneous radiofrequency interstitial thermal ablation of liver cancer has been evaluated. The technique has been recently improved by using modified needle electrodes (eg, expandable needle, cooled needle) that allow the ablation of tumors of less than 3.5 cm in diameter in only one session. Tumor necrosis has been shown by imaging techniques such as dynamic or spiral CT, MRI, selective hepatic angiography, ultrasonography-guided fine needle biopsy, and pathologic studies. Both in hepatocellular carcinoma and liver metastases, a complete necrosis has been obtained in more than 80% of the cases. The complication rate has been low without any mortality. In a series of hepatocellular carcinoma followed for a mean time of 23 months, median survival time has been 44 months, whereas recurrence rate was similar to that observed after surgery or ethanol injection. In two small series of metastases, the percentage of disease-free survivors at 1 year ranged from 11 to 66%. In conclusion, radiofrequency interstitial thermal ablation is a safe and effective technique for ablation of liver tumor; however, its precise role in the treatment of liver metastases needs to be defined.

Research advances of treatment planning of thermal ablation for liver cancer

With the development of thermal ablation techniques,thermal ablation has been a curative method in the treatment of liver cancer.Preoperative treatment planning as the first step in the thermal ablation process,its core purpose is to lower the complications,ensure tumor-free safety margin after ablation and improve patients' long-term survival.Preoperative treatment planning determines directly the effect of thermal ablation therapy.Preoperative treatment planning is significant to improve the accuracy and sci entific of thermal ablation therapy.Therefore,preoperative treatment planning of thermal ablation for liver cancer has become one of the research focuses in the thermal ablation fields.This review focuses on the treatment planning studies of image-guided thermal ablation for liver cancer in recent years. Key words: Liver cancer; Thermal ablation; Treatment planning

Percutaneous ultrasound-guided thermal ablation for liver tumor with artificial pleural effusion or ascites

Percutaneous ultrasound-guided thermal ablation is one of the major treatment methods for liver cancer. Tumor location close to the diaphragm or gastrointestinal tract was regarded as the treatment contraindication before due to poor visibility of the tumor or increased risk of thermal injury to the adjacent organs. This study used artificial pleural effusion or ascites to extend the indications of thermal ablation for liver cancer. Artificial pleural effusion (20 cases) or ascites (36 cases) was performed in 56 difficult cases of percutaneous thermal ablation for liver tumors. The technical success rates, the rate of approaching the procedure goal, complications, and local treatment response were assessed. The technical success rates were 95% (19/20) for artificial pleural effusion and 100% (36/36) for artificial ascites, the achieve purpose rates were 100% (19/19) and 91.7% (33/36), the complete ablation rates were 84.2% (16/19) and 93.9% (31/33), respectively. Coughing, transient hematuria, and subcutaneous effusion were observed in 3 patients after the procedure of artificial pleural effusion, and hydrothorax in the right chest occurred in 1 patient during the artificial ascites process. Thermal ablation with the use of artificial pleural effusion or ascites is a safe and effective treatment for liver tumors, and the technique can widen the indications of thermal ablation for liver tumors.

Lyso-thermosensitive liposomal doxorubicin: a novel approach to enhance efficacy of thermal ablation of liver cancer

Background: Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer death worldwide. No more than 30% of HCC patients receive curative treatment. Factors limiting curative therapy include tumor size and degree of liver impairment. Objective: To develop a cure for medium (3.1 – 5.0 cm) and large ( > 5 cm) tumors in seriously impaired livers. Method: Combine radiofrequency ablation (RFA) with lyso-thermosensitive liposomal doxorubicin (LTLD). Results/conclusions: RFA is used safely in patients with medium/large tumors and severe liver impairment; unclear tumor margins limit its curative efficacy. LTLD concentrates in the liver, where the anti-HCC chemotherapeutic, doxorubicin, is released into tumor margins by hyperthermia. RFA/LTLD can treat Child-Pugh class A-B patients with tumors up to 7 cm, a substantial increase in curable patients.

A 3-D Cell Method Formulation for Coupled Electric and Thermal Problems

A finite formulation is presented for the solution of coupled problems of steady-state electric and transient thermal conductions in 3-D regions. The model is based on the cell method approach and takes advantage of the very agile algebraic formulations that it can provide for field theories. Dual barycentric cell complexes are used for both space and time domains, the latter inducing a Crank-Nicolson time integration scheme. An example of application is given, consisting in the simulation of a treatment for the thermal ablation of liver cancer. Comparisons are given with a commercial finite-element method program

Technology for Radiofrequency Thermal Ablation of Liver Tumors

In this review the usefulness of percutaneous radiofrequency interstitial thermal ablation of liver cancer has been evaluated. The technique has been recently improved by using modified needle electrodes (eg, expandable needle, cooled needle) that allow the ablation of tumors of less than 3.5 cm in diameter in only one session. Tumor necrosis has been shown by imaging techniques such as dynamic or spiral CT, MRI, selective hepatic angiography, ultrasonography-guided fine needle biopsy, and pathologic studies. Both in hepatocellular carcinoma and liver metastases, a complete necrosis has been obtained in more than 80% of the cases. The complication rate has been low without any mortality. In a series of hepatocellular carcinoma followed for a mean time of 23 months, median survival time has been 44 months, whereas recurrence rate was similar to that observed after surgery or ethanol injection. In two small series of metastases, the percentage of disease-free survivors at 1 year ranged from 11 to 66%. In conclusion, radiofrequency interstitial thermal ablation is a safe and effective technique for ablation of liver tumor; however, its precise role in the treatment of liver metastases needs to be defined.