Technologies for Ablation of Hepatocellular Carcinoma Matthew R. Callstrom, J. William Charboneau  Gastroenterology  Volume 134, Issue 7, Pages 1831-1835 (June 2008) DOI: 10.1053/j.gastro.2008.05.022 Copyright © 2008 AGA Institute Terms and Conditions

Figure 1 US-guided placement of 1 of 3 internally-cooled RF electrodes into a liver tumor (Valleylab, division of Covidien, Mansfield, MA). The 3 electrodes are operated independently by a switching generator to allow placement of 1, 2, or 3 electrodes in the same or separate lesions. With the 3 electrodes in the tumor, an ablation defect of approximately 5 cm can be obtained over a period of approximately 15 minutes. Gastroenterology 2008 134, 1831-1835DOI: (10.1053/j.gastro.2008.05.022) Copyright © 2008 AGA Institute Terms and Conditions

Figure 2 RFA of small HCC. Small hepatocellular carcinoma in the lateral right lobe of the liver with characteristic cross-sectional imaging with (A) ultrasound imaging showing increased echogenicity of the mass relative to the normal liver (arrow), and (B) contrast-enhanced late arterial phase CT imaging shows a diffusely enhancing mass (arrow). (C) Contrast-enhanced CT with early arterial phase imaging during RF ablation of the small HCC using an RF cluster electrode (Valleylab, division of Covidien, Mansfield, MA). The zone of ablation is identified as an area of non-enhancing liver (arrow). (D) Contrast-enhanced CT 4 years post ablation demonstrates local control of the targeted mass with an area of non-enhancing liver corresponding to the ablation defect. Gastroenterology 2008 134, 1831-1835DOI: (10.1053/j.gastro.2008.05.022) Copyright © 2008 AGA Institute Terms and Conditions

Figure 3 Cryoablation of HCC. Contrast-enhanced axial (A) and coronal (B) CT demonstrates a new 2.5 cm hypodense mass (arrow) in the caudate lobe with mass effect upon the inferior vena cava (IVC). Prior surgical and ablation defects are also seen in the anterior and superior liver (i.e., segments 4a and 7) which were stable. Contiguous CT images (C and D) during percutaneous cryoablation show one of three cryoprobes bracketing the caudate tumor. The oval hypodense “ice ball” (arrowheads) extends beyond visible tumor margins and safely into the wall of the IVC. Note: the postero-lateral access in the left decubitus position allows parallel placement of a cryoprobe abutting the IVC, which generates more intense isotherms near the vessel wall and thorough tumor kill despite the massive heat-sink of the IVC. Follow up contrast-enhanced axial (E) and coronal (F) CT scan at 18 months confirms a markedly reduced oval hypodense area (arrows) representing the caudate ablation zone with no suspicious rim enhancement to suggest recurrence, even near the IVC. (Images courtesy of Peter Littrup, MD, Karmanos Cancer Institute, Detroit, MI) Gastroenterology 2008 134, 1831-1835DOI: (10.1053/j.gastro.2008.05.022) Copyright © 2008 AGA Institute Terms and Conditions