Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of p...Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly def ined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in diffi cult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an effi cient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.展开更多
Ablation therapy is one of the best curative treatment options for malignant liver tumors,and can be an alternative to resection.Radiofrequency ablation(RFA) of primary and secondary liver cancers can be performed saf...Ablation therapy is one of the best curative treatment options for malignant liver tumors,and can be an alternative to resection.Radiofrequency ablation(RFA) of primary and secondary liver cancers can be performed safely using percutaneous,laparoscopic,or open surgical techniques,and RFA has markedly changed the treatment strategy for small hepatocellular carcinoma(HCC).Percutaneous RFA can achieve the same overall and disease-free survival as surgical resection for patients with small HCC.The use of a laparoscopic or open approach allows repeated placements of RFA electrodes at multiple sites to ablate larger tumors.RFA combined with transcatheter arterial chemoembolization will make the treatment of larger tumors a clinically viable treatment alternative.However,an accurate evaluation of treatment response is very important to secure successful RFA therapy.Since a sufficient safety margin(at least 0.5 cm) can prevent local tumor recurrences,an accurate evaluation of treatment response is very important to secure successful RFA therapy.To minimize complications of RFA,clinicians should be familiar with the imaging features of each type of complication.Appropriate management of complications is essential for successful RFA treatment.展开更多
Radiofrequency ablation(RFA)is commonly applied for the treatment of hepatocellular carcinoma(HCC)because of the facile procedure,and the safety and effectiveness for the treatment of this type of tumor.On the other h...Radiofrequency ablation(RFA)is commonly applied for the treatment of hepatocellular carcinoma(HCC)because of the facile procedure,and the safety and effectiveness for the treatment of this type of tumor.On the other hand,it is believed that HCC cells should spread predominantly through the blood flow of the portal vein,which could lead to the formation of intrahepatic micrometastases.Therefore,monitoring tumor response after the treatment is quite important and accurate assessment of treatment response is critical to obtain the most favorable outcome after the RFA.Indeed,several reports suggested that even small HCCs of≤3 cm in diameter might carry intrahepatic micrometastases and/or microvascular invasion.From this point of view,for preventing local recurrences,RFA should be performed ablating a main tumor as well as its surrounding non-tumorous liver tissue where micrometastases and microvascular invasion might exist.Recent advancement of imaging modalities such as contrast-enhanced ultrasonic,computed tomography,and magnetic resonance imaging are playing an important role on assessing the therapeutic effects of RFA.The local recurrence rate tends to be low in HCC patients who were proven to have adequate ablation margin after RFA;namely,not only disappearance of vascular enhancement of main tumor,but also an adequate ablation margin.Therefore,contrast enhancement gives important findings for the diagnosis of recurrent HCCs on each imaging.However,hyperemia of non-tumorous liver surrounding the ablated lesion,which could be attributed to an inflammation after RFA,may well obscure the findings of local recurrence of HCCs after RFA.Therefore,we need to carefully address to these imaging findings given the fact that diagnostic difficulties of local recurrence of HCC.Here,we give an overview of the current status of the imaging assessment of HCC response to RFA.展开更多
The success rate of percutaneous radiofrequency(RF)ablation for hepatocellular carcinoma(HCC)depends on correct targeting via an imaging technique.However,RF electrode insertion is not completely accurate for residual...The success rate of percutaneous radiofrequency(RF)ablation for hepatocellular carcinoma(HCC)depends on correct targeting via an imaging technique.However,RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound(US),color Doppler,and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue.Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver.Two breakthroughs in the field of US technology,harmonic imaging and the development of second-generation contrast agents,have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions.Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor.Therefore,contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC,which is poorly depicted by B-mode US.The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.展开更多
Ultrasonography(US) findings are inevitably based on pathological features.Knowledge of the pathological features of hepatic malignancies such as hepatocellular carcinoma(HCC),liver metastasis and intrahepatic cholang...Ultrasonography(US) findings are inevitably based on pathological features.Knowledge of the pathological features of hepatic malignancies such as hepatocellular carcinoma(HCC),liver metastasis and intrahepatic cholangiocarcinoma is essential for correct US diagnosis and appropriate management.One type of hepatocarcinogenesis is step-wise development from a low-grade dysplastic nodule(DN),high-grade DN,high-grade DN with malignant foci,and well-differentiated HCC,to classical HCC.The intranodular blood supply changes in accordance with this progression.Moreover,the malignant potential tends to change as the macroscopic configuration progresses.Therefore,typical US findings of advanced HCC are a mosaic pattern,septum formation,peripheral sonolucency(halo),lateral shadow produced by fibrotic pseudocapsule,posterior echo enhancement,arterial hypervascularity with dilated intratumoral blood sinusoids,and perinodular daughter nodule formation.Bull's eye appearance is a common presentation of metastases from gastrointestinal(GI) adenocarcinomas,and represents histological findings that show an area of central necrosis surrounded by a zonal area of viable tumor.Thick zonal area reflects the layer of viable cells that are fed by minute tumor vessels.US imaging features of liver metastases from the GI tract are as follows:Bull's eye appearance,multiple masses,irregular tumor border,arterial rim-like enhancement,and hypoenhancement in the late vascular phase.Most intrahepatic cholangiocarcinomas are ductal adenocarcinomas.The bile ducts peripheral to the tumor are usually dilated because of obstruction by tumors.US imaging features of mass-forming cholangiocarcinoma are as follows:peripheral bile duct dilatation,irregular tumor border,arterial enhancement due to minute intratumoral blood sinusoids,and hypoenhancement in the late vascular phase.展开更多
With the development of second-generation contrast agents and advancement in contrast harmonic imaging,contrast-enhanced ultrasonography(CEUS)now has the capacity to sensitively and accurately show tumor vascularity.T...With the development of second-generation contrast agents and advancement in contrast harmonic imaging,contrast-enhanced ultrasonography(CEUS)now has the capacity to sensitively and accurately show tumor vascularity.Therefore,marked improvements have been achieved in the diagnosis of focal liver lesions(FLLs),including hepatocellular carcinoma(HCC),by US.In contrast to other agents,Kupffer cells in liver sinusoids take up Sonazoid.Two contrast enhancement phases occur in CEUS with Sonazoid:a vascular phase and Kupffer phase.Images obtained in the Kupffer phase have higher diagnostic sensitivity for hepatic malignancies because the majority of these malignancies do not contain Kupffer cells.Dynamic images obtained in the vascular phase markedly narrow the clinical differential diagnoses of FLLs.The sustainable detection of inconspicuous HCC,adequate guidance of ablation therapy,and accurate assessment of treatment responses in HCC are all facilitated by Sonazoid.The principles,clinical applications,and techniques of CEUS with Sonazoid in the diagnosis of HCC will be reviewed herein.展开更多
Introduction Hepatocellular carcinoma(HCC)is one of the leading causes of cancer-related mortality.Because HCC typically occurs in patients with advanced liver disease,therapeutic decisions depend on the degree of und...Introduction Hepatocellular carcinoma(HCC)is one of the leading causes of cancer-related mortality.Because HCC typically occurs in patients with advanced liver disease,therapeutic decisions depend on the degree of underlying liver dysfunction and tumor burden.Curative treatment options,which result in 5-year survival rates of 60–80%(surgical resection)and 40–70%(local ablative therapies),are restricted to patients with early-stage HCC(1,2).However,surgical resection and local ablative therapies are limited by high tumor recurrence rates of 50%at 3 years and 70%at 5 years(1-6).Thus,monitoring treatment response is imperative for the clinical management of HCC patients(7),highlighting the need for adjuvant therapies.展开更多
文摘Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly def ined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in diffi cult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an effi cient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.
文摘Ablation therapy is one of the best curative treatment options for malignant liver tumors,and can be an alternative to resection.Radiofrequency ablation(RFA) of primary and secondary liver cancers can be performed safely using percutaneous,laparoscopic,or open surgical techniques,and RFA has markedly changed the treatment strategy for small hepatocellular carcinoma(HCC).Percutaneous RFA can achieve the same overall and disease-free survival as surgical resection for patients with small HCC.The use of a laparoscopic or open approach allows repeated placements of RFA electrodes at multiple sites to ablate larger tumors.RFA combined with transcatheter arterial chemoembolization will make the treatment of larger tumors a clinically viable treatment alternative.However,an accurate evaluation of treatment response is very important to secure successful RFA therapy.Since a sufficient safety margin(at least 0.5 cm) can prevent local tumor recurrences,an accurate evaluation of treatment response is very important to secure successful RFA therapy.To minimize complications of RFA,clinicians should be familiar with the imaging features of each type of complication.Appropriate management of complications is essential for successful RFA treatment.
文摘Radiofrequency ablation(RFA)is commonly applied for the treatment of hepatocellular carcinoma(HCC)because of the facile procedure,and the safety and effectiveness for the treatment of this type of tumor.On the other hand,it is believed that HCC cells should spread predominantly through the blood flow of the portal vein,which could lead to the formation of intrahepatic micrometastases.Therefore,monitoring tumor response after the treatment is quite important and accurate assessment of treatment response is critical to obtain the most favorable outcome after the RFA.Indeed,several reports suggested that even small HCCs of≤3 cm in diameter might carry intrahepatic micrometastases and/or microvascular invasion.From this point of view,for preventing local recurrences,RFA should be performed ablating a main tumor as well as its surrounding non-tumorous liver tissue where micrometastases and microvascular invasion might exist.Recent advancement of imaging modalities such as contrast-enhanced ultrasonic,computed tomography,and magnetic resonance imaging are playing an important role on assessing the therapeutic effects of RFA.The local recurrence rate tends to be low in HCC patients who were proven to have adequate ablation margin after RFA;namely,not only disappearance of vascular enhancement of main tumor,but also an adequate ablation margin.Therefore,contrast enhancement gives important findings for the diagnosis of recurrent HCCs on each imaging.However,hyperemia of non-tumorous liver surrounding the ablated lesion,which could be attributed to an inflammation after RFA,may well obscure the findings of local recurrence of HCCs after RFA.Therefore,we need to carefully address to these imaging findings given the fact that diagnostic difficulties of local recurrence of HCC.Here,we give an overview of the current status of the imaging assessment of HCC response to RFA.
文摘The success rate of percutaneous radiofrequency(RF)ablation for hepatocellular carcinoma(HCC)depends on correct targeting via an imaging technique.However,RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound(US),color Doppler,and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue.Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver.Two breakthroughs in the field of US technology,harmonic imaging and the development of second-generation contrast agents,have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions.Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor.Therefore,contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC,which is poorly depicted by B-mode US.The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.
文摘Ultrasonography(US) findings are inevitably based on pathological features.Knowledge of the pathological features of hepatic malignancies such as hepatocellular carcinoma(HCC),liver metastasis and intrahepatic cholangiocarcinoma is essential for correct US diagnosis and appropriate management.One type of hepatocarcinogenesis is step-wise development from a low-grade dysplastic nodule(DN),high-grade DN,high-grade DN with malignant foci,and well-differentiated HCC,to classical HCC.The intranodular blood supply changes in accordance with this progression.Moreover,the malignant potential tends to change as the macroscopic configuration progresses.Therefore,typical US findings of advanced HCC are a mosaic pattern,septum formation,peripheral sonolucency(halo),lateral shadow produced by fibrotic pseudocapsule,posterior echo enhancement,arterial hypervascularity with dilated intratumoral blood sinusoids,and perinodular daughter nodule formation.Bull's eye appearance is a common presentation of metastases from gastrointestinal(GI) adenocarcinomas,and represents histological findings that show an area of central necrosis surrounded by a zonal area of viable tumor.Thick zonal area reflects the layer of viable cells that are fed by minute tumor vessels.US imaging features of liver metastases from the GI tract are as follows:Bull's eye appearance,multiple masses,irregular tumor border,arterial rim-like enhancement,and hypoenhancement in the late vascular phase.Most intrahepatic cholangiocarcinomas are ductal adenocarcinomas.The bile ducts peripheral to the tumor are usually dilated because of obstruction by tumors.US imaging features of mass-forming cholangiocarcinoma are as follows:peripheral bile duct dilatation,irregular tumor border,arterial enhancement due to minute intratumoral blood sinusoids,and hypoenhancement in the late vascular phase.
文摘With the development of second-generation contrast agents and advancement in contrast harmonic imaging,contrast-enhanced ultrasonography(CEUS)now has the capacity to sensitively and accurately show tumor vascularity.Therefore,marked improvements have been achieved in the diagnosis of focal liver lesions(FLLs),including hepatocellular carcinoma(HCC),by US.In contrast to other agents,Kupffer cells in liver sinusoids take up Sonazoid.Two contrast enhancement phases occur in CEUS with Sonazoid:a vascular phase and Kupffer phase.Images obtained in the Kupffer phase have higher diagnostic sensitivity for hepatic malignancies because the majority of these malignancies do not contain Kupffer cells.Dynamic images obtained in the vascular phase markedly narrow the clinical differential diagnoses of FLLs.The sustainable detection of inconspicuous HCC,adequate guidance of ablation therapy,and accurate assessment of treatment responses in HCC are all facilitated by Sonazoid.The principles,clinical applications,and techniques of CEUS with Sonazoid in the diagnosis of HCC will be reviewed herein.
文摘Introduction Hepatocellular carcinoma(HCC)is one of the leading causes of cancer-related mortality.Because HCC typically occurs in patients with advanced liver disease,therapeutic decisions depend on the degree of underlying liver dysfunction and tumor burden.Curative treatment options,which result in 5-year survival rates of 60–80%(surgical resection)and 40–70%(local ablative therapies),are restricted to patients with early-stage HCC(1,2).However,surgical resection and local ablative therapies are limited by high tumor recurrence rates of 50%at 3 years and 70%at 5 years(1-6).Thus,monitoring treatment response is imperative for the clinical management of HCC patients(7),highlighting the need for adjuvant therapies.
