Luigi Solbiati

Sustained complete response and complications rates after radiofrequency ablation of very early hepatocellular carcinoma in cirrhosis: Is resection still the treatment of choice?

If liver transplantation is not feasible, partial resection is considered the treatment of choice for hepatocellular carcinoma (HCC) in patients with cirrhosis. However, in some centers the first‐line treatment for small, single, operable HCC is now radiofrequency ablation (RFA). In the current study, 218 patients with single HCC ≤ 2.0 cm (very early or T1 stage) underwent RFA. We assessed 2 primary end points that could be easily compared with those reported for resective surgery: (1) the rate of sustained, local, complete response and (2) the rate of treatment‐related complications. The secondary end point was 5‐year survival in the 100 patients whose tumors had been considered potentially operable. After a median follow‐up of 31 months, sustained complete response was observed in 216 patients (97.2%). In the remaining 6, percutaneous ethanol injection, selective intraarterial chemoembolization, or resection were used as salvage therapy. Perioperative mortality, major complication, and 5‐year survival rates were 0%, 1.8%, and 68.5%, respectively. Conclusion: Compared with resection, RFA is less invasive and associated with lower complication rate and lower costs. RFA is also just as effective for ensuring local control of stage T1 HCC, and it is associated with similar survival rates (as recently demonstrated by 2 randomized trials). These data indicate that RFA can be considered the treatment of choice for patients with single HCC ≤ 2.0 cm, even when surgical resection is possible. Other approaches can be used as salvage therapy for the few cases in which RFA is unsuccessful or unfeasible. (HEPATOLOGY 2007.)

PERCUTANEOUS RADIOFREQUENCY TISSUE ABLATION : DOES PERFUSION-MEDIATED TISSUE COOLING LIMIT COAGULATION NECROSIS ?

PURPOSE To determine, by decreasing hepatic perfusion during radiofrequency (RF) ablation, whether perfusion-mediated tissue cooling can explain the reduced coagulation observed in in vivo studies compared to that seen with RF application in ex vivo tissue. MATERIALS AND METHODS RF was applied in vivo with use of cooled-tip electrodes to normal porcine liver without (n = 8) and with balloon occlusion of the portal vein (n = 8), celiac artery (n = 3), or hepatic artery (n = 2), and to ex vivo calf liver (n = 10). In vivo trials of vasopressin (0.3-0.6 U/min) infusion during RF application with (n = 10) and without (n = 2) arterial balloon occlusion were also performed. Intraoperative RF was subsequently performed in seven patients with hepatic colorectal metastases with and without portal inflow occlusion. Remote thermometry was performed in four patients. RESULTS RF application (12 minutes) during portal venous occlusion produced larger areas of coagulation necrosis than RF with unaltered blood flow (2.9 cm +/- 0.1 vs 2.4 cm +/- 0.2 diameter; P < .01). With celiac and hepatic artery occlusion, coagulation diameter measured 2.7 cm +/- 0.2 and 2.5 cm +/- 0.1, respectively. Infusion of vasopressin without vascular occlusion reduced coagulation diameter to 1.1 cm. However, different methods of hepatic or celiac arterial balloon occlusion with simultaneous vasopressin infusion produced a mean 3.4 cm +/- 0.2 of necrosis. Coagulation in ex vivo liver was 2.9 cm +/- 0.1 in diameter. Clinical studies demonstrated greater coagulation diameter for metastases treated during portal inflow occlusion (4.0 cm +/- 1.3) than for tumors treated with normal blood flow (2.5 cm +/- 0.8; P < .05). Thermometry documented a 10 degrees C increase compared to baseline at 10 mm and 20 mm from the electrode after 5 minutes of portal inflow occlusion during constant RF application. CONCLUSIONS Perfusion-mediated tissue cooling reduces coagulation necrosis achievable with RF ablation. Reduction of blood flow during RF application increases coagulation in both an animal model and human liver metastases.

Radiofrequency tissue ablation: Increased lesion diameter with a perfusion electrode

RATIONALE AND OBJECTIVES We sought to induce large zones of coagulation necrosis using radiofrequency (RF) with perfusion electrodes and to define optimal parameters for this system. METHODS We developed RF electrodes with internal cannulas to enable tip perfusion. Lesions were created with monopolar RF in ex vivo and in vivo liver and muscle tissue with and without perfusion of the electrode tip using 0 degree C saline. In separate experiments, wattage, current, procedure duration, tip exposure, and perfused tip temperatures were studied. RESULTS In ex vivo liver tissue, a maximum lesion diameter of 3.1 cm without charring occurred with perfusion at 12 min and 50 W. In in vivo liver tissue with perfusion (tip temperature = 25-35 degrees C) and a 3-cm tip exposure, 80 W were deposited in muscle tissue and 65 W in liver tissue for 12 min without inducing charring. Lesion diameters were 4.5 cm and 2.4 cm, respectively. By comparison, without perfusion a maximum of 20 W could be deposited into either tissue type, resulting in 1.8-cm muscle lesions and 1.2-cm liver lesions. Tip temperatures between 45 degrees C and 55 degrees C resulted in charring. Smaller but predictable lesion diameters were created with a lower power, a shorter tip exposure, or both. Of all the parameters, diameter correlated best with the current applied. CONCLUSION Perfusion of RF electrodes with chilled saline allows for increased power deposition without tissue charring, increasing the volume of coagulation necrosis created with a single electrode insertion. Perfusion electrodes therefore might decrease the number of probe insertions required for percutaneous tumor ablation therapy or allow for the treatment of larger lesions.

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria—A 10-Year Update

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes. Online supplemental material is available for this article .

Image-guided tumor ablation: standardization of terminology and reporting criteria.

The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency (RF), laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the groups intention that adherence to the recommendations will facilitate achievement of the groups main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes. The intent of this standardization of terminology is to provide an appropriate vehicle for reporting the various aspects of image-guided ablation therapy.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver – Update 2012

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Radiofrequency thermal ablationof hepatic metastases

Abstract Percutaneous radiofrequency (RF) ablation is a promising therapeutic option for liver metastases, which may result in prolonged survival and chance for cure. Recent technological advancements provide larger coagulation volumes, allowing treatment of medium- and large-size metastases. Candidates are patients with metachronous liver metastases from colorectal or other primary cancers, in whom surgery is contraindicated and with one to four nodules each smaller than approx. 4 cm. We treated 109 patients with 172 colorectal metastases in the liver. Local control was obtained in 70.4% of lesions. Recurrence was significantly more frequent in lesions >3 cm. One major complication occurred (0.6% of sessions), a large bowel perforation requiring surgery. Seven minor complications did not require therapy. New metastases developed at follow-up in 50.4% of patients. Survival rates are 67% and 33% after 2 and 3 years, respectively; estimated median survival being 30 months. RF ablation advantages include minimal-invasiveness (no mortality, significantly lower complications), reduced costs and hospital stays compared to surgery, feasibility in non-surgical candidates, and the potential of repeated treatment if local recurrence occurs or new metastases develop.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update.

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

Small Liver Colorectal Metastases Treated with Percutaneous Radiofrequency Ablation: Local Response Rate and Long-term Survival with Up to 10-year Follow-up

PURPOSE To determine the long-term (10-year) survival of patients with colorectal liver metastases treated with radiofrequency (RF) ablation and systemic chemotherapy with intention to treat. MATERIALS AND METHODS Institutional review board approval was obtained for this study. From 1997 to 2006, 99 consecutive patients with 202 small (0.8-4.0 cm; mean: 2.2 cm ± 1.1) metachronous colorectal liver metastases underwent ultrasonography-guided percutaneous RF ablation with internally-cooled electrodes in association with systemic chemotherapy. Patients ineligible for surgery (n = 80) or whose lesions were potentially resectable and who refused surgery (n = 19) were included. Patients were followed up with contrast agent-enhanced computed tomography and/or magnetic resonance imaging for a minimum of 3 years to more than 10 years after RF ablation (n = 99, 67, 49, and 25 for 3, 5, 7, and 10 or more years, respectively). Overall local response rates and long-term survival rates were assessed. For each of these primary endpoints, Kaplan-Meier curves were generated and log-rank tests were used to assess for statistically significant differences. RESULTS Primary and secondary technical success rates were 93.1% (188 of 202) and 100% (14 of 14), respectively. Local tumor progression occurred in 11.9% (24 of 202) metastases, and 54.2% (13 of 24) of these were re-treated. Patient survival rates increased with re-treatment versus no re-treatment (P < .001). At follow-up, 125 new liver metastases were found, and of these 32.8% (41 of 125) were treated with RF ablation. Overall survival rates were 98.0%, 69.3%, 47.8%, 25.0%, and 18.0% (median: 53.2 months) at 1, 3, 5, 7, and 10 years, respectively. The major complication rate was 1.3% (two of 156), and there were no procedure-related deaths. At the time this article was written, 32.3% (32 of 99) of the patients were alive, and 67.7% (67 of 99) were deceased, with a median follow-up of 72 months. CONCLUSION Adding RF ablation to systemic chemotherapy achieved local control in a large majority of metachronous colorectal liver metastases. The 3- to 10-year survival rates of this relatively large series of patients were essentially equivalent to those of most surgical series reported in the literature.

Variables Affecting Proper System Grounding for Radiofrequency Ablation in an Animal Model

PURPOSE The authors sought to determine which factors contribute to excessive thermal deposition and burns at the grounding pad site after high-current percutaneous, image-guided radiofrequency (RF) ablation. MATERIALS AND METHODS Radiofrequency (1,000-2,000 mA) was applied for 10 minutes with use of an internally-cooled electrode placed into in vivo pig livers (n = 88). In separate experiments, the number of pads (1, 2, or 4), orientation of pads (horizontal, vertical, or diagonal), and distance between the pads and the electrode (10-50 cm) of mesh or foil grounding pads (12.5 x 8 cm; 100 cm2) were varied. Thermistors measured skin surface temperatures during ablation. Pathologic analysis of skin changes was performed. RESULTS Temperature elevations at the grounding pad were observed for every trial, with a temperature elevation > or =12 degrees C (as high as 45 degrees C) observed in 60 of 88 trials (68.2%). Temperatures at the grounding site pad were dependent on all variables studied, including the grounding pad surface area, the amount of current deposited in the liver, the orientation of the pad, and the pads distance from the electrode. Second-degree burns were seen with temperatures exceeding 47 degrees C and third-degree burns were observed when a temperature > or = 52 degrees C was noted. For a given set of RF parameters, reduced heating was observed for trials in which foil grounding pads were used (P < .001). Grounding pad burns did not occur at 2,000 mA (maximum generator output) when four foil pads were placed horizontally > or = 25 cm from the electrode. CONCLUSIONS High-current RF ablation can induce severe burns at the grounding pad site if inadequate precautions are taken. To minimize the risk of burns, multiple large-surface-area foil pads should be placed on well-prepared skin and oriented with the longest surface edge facing the RF electrode.