Mr Imaging of the Liver before and after Transcatheter Hepatic Chemo-Embolization for Hepatocellular Carcinoma

Treatment with high intensity focused ultrasound: secrets revealed

For many decades open surgery remained the only way available for local control of body tumors. In order to decrease the patients' morbidity and mortality several image guided minimally invasive procedures have been adopted. High intensity focused ultrasound (HIFU) is an extracorporeal non invasive method for tumor ablation. High intensity ultrasonic waves can be focused to a focal point resulting in lethal elevation of the temperature at the target site with consequent damage of the tumoral cells. The advances in HIFU technology during the past two decades expanded the HIFU applications to include ablation of both benign and malignant tumors with different treatment strategies being implemented for each type. The aim of this review is to introduce the reader to the details of the treatment process including pretreatment preparation, treatment planning, different ablation strategies, patients' after care as well as the follow up regimens for the most common HIFU applications.

Radiologic-pathologic correlation of hepatocellular carcinoma treated with chemoembolization

To correlate posttreatment radiologic and pathologic findings in patients who underwent transarterial chemoembolization before transplantation or resection. Thirty-five patients with postchemoembolization follow-up imaging underwent liver transplantation/resection. Pre- and posttreatment contrast-enhanced magnetic resonance imaging were used to evaluate radiologic findings. Imaging characteristics using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria after treatment were evaluated. Treated lesions were examined by pathology (gold standard) for the assessment of necrosis. Radiologic findings on magnetic resonance imaging were correlated to pathologic findings to assess the predictability by imaging of actual necrosis. Kappa (κ) statistics were used to determine intermethod agreement between WHO and EASL criteria. Fourteen (40%) of 35 lesions had biopsy-proven hepatocellular carcinoma. Thirteen (37%) of 35 target lesions showed complete pathologic necrosis. Complete pathologic necrosis was seen in 35% of lesions with pretreatment size <3 cm. Complete pathologic necrosis was seen in 1 (100%) of 1, 6 (67%) of 9, 6 (33%) of 18, and 0 (0%) of 7 of the lesions that exhibited complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD) by WHO criteria, respectively. Complete pathologic necrosis was seen in 9 (82%) of 11, 4 (36%) of 11, 0 (0%) of 8, and 0 (0%) of 5 of the lesions that showed CR, PR, SD, or PD by EASL criteria, respectively. EASL CR and WHO response were shown to have ≥85% specificity for predicting complete pathologic necrosis. The κ coefficient for agreement between WHO and EASL was 0.29. EASL and WHO criteria had minimal intermethod agreement. EASL CR and WHO response were able to predict pathologic necrosis.

Advanced hepatocellular carcinoma: treatment with high-intensity focused ultrasound ablation combined with transcatheter arterial embolization

PURPOSE

To evaluate ultrasonographically (US)-guided high-intensity focused ultrasound ablation combined with transcatheter arterial chemoembolization (TACE) in the treatment of stage IVA hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. From November 1998 to May 2000, 50 consecutive patients with stage IVA HCC (TNM classification, T4N0-1M0) were alternately enrolled in one of two treatment groups: group 1 (n = 26), in which TACE was performed alone, and group 2 (n = 24), in which transcutaneous ablation of HCC with high-intensity focused ultrasound was performed 2-4 weeks after TACE. The tumors were 4-14 cm in diameter (mean, 10.5 cm). Immediate therapeutic effects were assessed at follow-up with Doppler US and computed tomography or magnetic resonance imaging. All patients were followed up for 3-24 months (mean, 8 months) to observe long-term therapeutic effects and complications in both groups. Tumor reduction rates, median survival time, and cumulative survival rates in both groups were calculated by using the unpaired Student t test and Kaplan-Meier method.

RESULTS

No severe complication was observed after focused ultrasound ablation, and no unexpected side effects were noted after TACE. Follow-up images showed absence or reduction of blood supply in the lesions after focused ultrasound ablation when compared with blood supply after TACE alone. The median survival time was 11.3 months in group 2 and 4.0 months in group 1 (P = .004). The 6-month survival rate was 80.4%-85.4% in group 2 and 13.2% in group 1 (P = .002), and the 1-year survival rate was 42.9% and 0%, respectively. Median reductions in tumor size as a percentage of initial tumor volume at 1, 3, 6, and 12 months after treatment, respectively, were 28.6%, 35.0%, 50.0%, and 50.0% in group 2 and 4.8%, 7.7%, 10.0%, and 0% in group 1 (P < .01).

CONCLUSION

The combination of high-intensity focused ultrasound ablation and TACE is a promising approach in patients with advanced-stage HCC, but large-scale randomized clinical trials are necessary for confirmation.

Evaluation of therapeutic effectiveness of transarterial chemoembolization for hepatocellular carcinoma: correlation of dynamic susceptibility contrast-enhanced echoplanar imaging and hepatic angiography

The objective of this study was to evaluate the therapeutic effectiveness of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI). Seventeen patients with histopathologically proven HCC were included in this study. All patients underwent MR examinations with conventional T1- and T2-weighted images, gadolinium-enhanced images, and DSC-MRI before TACE treatment. Hepatic blood volume (HBV) maps were reconstructed from the time-intensity curves. The same MRI sequences and techniques were repeated 24 h and 6 weeks after TACE. Serial changes in tumor perfusion on HBV maps were correlated with vascularity in hepatic angiography. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. Heterogeneous enhancement was observed in all tumors before and immediately after TACE. Hyperperfusion was noted in most of the tumors on HBV map before TACE and moderate to marked hypoperfusion following TACE. The degree of tumor perfusion on HBV map correlated well with the vascularity in angiography. In conclusion, the noninvasive nature of DSC-MRI is useful to evaluate the effectiveness of TACE. Invasive procedures, such as angiography, are seldom necessary.

Diagnostic imaging and interventional therapy of hepatocellular carcinoma

Diagnostic imaging has many important roles in the management of patients with hepatocellular carcinoma (HCC). In diagnosis, lipiodol CT (LCT) has been shown to be the most sensitive imaging modality (90-97%) for all sizes of lesions; all other modalities have high sensitivities for lesions 1-3 cm but low sensitivities for lesions < 1 cm (ultrasound 33-37%, conventional CT 20-42% and digital subtraction angiography 40-55%). All imaging modalities understage HCC. Once again LCT is the most accurate method of evaluating the extent of tumour, but even this method does not identify all satellite nodules. Ultrasound has been proposed as a screening method, but this cannot be justified on the basis of its results or cost benefit analysis. Both CT and dynamic MRI play useful roles in evaluating the efficacy and follow-up of patients undergoing chemoembolization (TACE) and percutaneous ethanol injection (PEI). Although surgery remains the best treatment of HCC, it is unsuitable in most of the cases which would be better treated with interventional therapy. This article presents a review of the literature regarding the use of TACE, PEI or a combination of both procedures in the treatment of HCC. A multicentric study has shown that patients with monofocal lesions less than 5 cm in diameter are better treated with PEI, which is therefore a good alternative to the surgical treatment; patients with multifocal lesions (maximum of three lesions) show a better survival with TACE. Combined treatment with TACE and PEI proves to be effective in patients with large HCC.