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Radiofrequency ablation of liver cancer: early evaluation of therapeutic response with contrast-enhanced ultrasonography.

Choi D, Lim HK, Lee WJ, Kim SH, Kim MJ, Kim SK, Jang KM, Lee JY, Lim JH - Korean J Radiol (2004 Jul-Sep)

Bottom Line: The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases.Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors.Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-gu, Seoul, Korea. hklim@smc.samsung.co.kr

ABSTRACT
The early assessment of the therapeutic response after percutaneous radiofrequency (RF) ablation is important, in order to correctly decide whether further treatment is necessary. The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases. Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors. Contrast-enhanced gray-scale US, using a harmonic technology which has recently been introduced, allows for the detection of residual tumors after ablation, without any of the blooming or motion artifacts usually seen on contrast-enhanced color or power Doppler US. Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer. This technique was also useful in targeting any residual unablated tumors encountered during additional ablation.

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Related in: MedlinePlus

A 74-year-old-man with hepatic metastasis from colon cancer before and after radiofrequency ablation.A, B. Contrast-enhanced agent detection imaging obtained at 20 and 70 sec-delay shows a 2.5-cm metastatic tumor (arrows) with internal vascularity and irregular rim-like enhancement.C. US shows an electrode placement within the index tumor.D. The following morning, 19 hours after radiofrequency ablation, contrast-enhanced agent detection imaging obtained at 25 sec-delay shows the index tumor (arrows) and no vascularity within the ablation zone.E. Acoustic emission imaging with a rapid sweeping technique at 60 sec-delay shows that all the ablation zone is avascular without peripheral enhancement.
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Figure 9: A 74-year-old-man with hepatic metastasis from colon cancer before and after radiofrequency ablation.A, B. Contrast-enhanced agent detection imaging obtained at 20 and 70 sec-delay shows a 2.5-cm metastatic tumor (arrows) with internal vascularity and irregular rim-like enhancement.C. US shows an electrode placement within the index tumor.D. The following morning, 19 hours after radiofrequency ablation, contrast-enhanced agent detection imaging obtained at 25 sec-delay shows the index tumor (arrows) and no vascularity within the ablation zone.E. Acoustic emission imaging with a rapid sweeping technique at 60 sec-delay shows that all the ablation zone is avascular without peripheral enhancement.

Mentions: In our unpublished data concerning 52 HCCs, neither contrast-enhanced ADI the following morning nor 1-month follow-up CT showed evidence of enhancing foci within the 49 (94%) ablation zones (Fig. 7). In the remaining three (6%) ablation zones, irregular peripheral-enhancing foci were found on contrast-enhanced ADI (Fig. 8). All of these were found to have the enhancing portion at the same location as that of the corresponding lesions observed during the hepatic arterial or portal venous phases on the 1-month follow-up CT (Fig. 8). Among the 49 ablated HCCs without residual unablated tumors, either on CT or contrast-enhanced ADI, two (4%) had follow-up CT findings of local tumor progression in the ablation zones. A more recent report (13) also suggested that contrast-enhanced ADI was useful and as effective as CT for evaluating the therapeutic response to RF ablation and TACE in patients with malignant hepatic tumors (Fig. 9).


Radiofrequency ablation of liver cancer: early evaluation of therapeutic response with contrast-enhanced ultrasonography.

Choi D, Lim HK, Lee WJ, Kim SH, Kim MJ, Kim SK, Jang KM, Lee JY, Lim JH - Korean J Radiol (2004 Jul-Sep)

A 74-year-old-man with hepatic metastasis from colon cancer before and after radiofrequency ablation.A, B. Contrast-enhanced agent detection imaging obtained at 20 and 70 sec-delay shows a 2.5-cm metastatic tumor (arrows) with internal vascularity and irregular rim-like enhancement.C. US shows an electrode placement within the index tumor.D. The following morning, 19 hours after radiofrequency ablation, contrast-enhanced agent detection imaging obtained at 25 sec-delay shows the index tumor (arrows) and no vascularity within the ablation zone.E. Acoustic emission imaging with a rapid sweeping technique at 60 sec-delay shows that all the ablation zone is avascular without peripheral enhancement.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698161&req=5

Figure 9: A 74-year-old-man with hepatic metastasis from colon cancer before and after radiofrequency ablation.A, B. Contrast-enhanced agent detection imaging obtained at 20 and 70 sec-delay shows a 2.5-cm metastatic tumor (arrows) with internal vascularity and irregular rim-like enhancement.C. US shows an electrode placement within the index tumor.D. The following morning, 19 hours after radiofrequency ablation, contrast-enhanced agent detection imaging obtained at 25 sec-delay shows the index tumor (arrows) and no vascularity within the ablation zone.E. Acoustic emission imaging with a rapid sweeping technique at 60 sec-delay shows that all the ablation zone is avascular without peripheral enhancement.
Mentions: In our unpublished data concerning 52 HCCs, neither contrast-enhanced ADI the following morning nor 1-month follow-up CT showed evidence of enhancing foci within the 49 (94%) ablation zones (Fig. 7). In the remaining three (6%) ablation zones, irregular peripheral-enhancing foci were found on contrast-enhanced ADI (Fig. 8). All of these were found to have the enhancing portion at the same location as that of the corresponding lesions observed during the hepatic arterial or portal venous phases on the 1-month follow-up CT (Fig. 8). Among the 49 ablated HCCs without residual unablated tumors, either on CT or contrast-enhanced ADI, two (4%) had follow-up CT findings of local tumor progression in the ablation zones. A more recent report (13) also suggested that contrast-enhanced ADI was useful and as effective as CT for evaluating the therapeutic response to RF ablation and TACE in patients with malignant hepatic tumors (Fig. 9).

Bottom Line: The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases.Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors.Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-gu, Seoul, Korea. hklim@smc.samsung.co.kr

ABSTRACT
The early assessment of the therapeutic response after percutaneous radiofrequency (RF) ablation is important, in order to correctly decide whether further treatment is necessary. The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases. Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors. Contrast-enhanced gray-scale US, using a harmonic technology which has recently been introduced, allows for the detection of residual tumors after ablation, without any of the blooming or motion artifacts usually seen on contrast-enhanced color or power Doppler US. Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer. This technique was also useful in targeting any residual unablated tumors encountered during additional ablation.

Show MeSH
Related in: MedlinePlus