MEDLINE Abstracts: Radiofrequency for Hepatic Malignancies
MEDLINE Abstracts: Radiofrequency for Hepatic Malignancies
What's new concerning the role of radiofrequency ablation in the treatment of unresectable liver tumors? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Gastroenterology.
Bleicher RJ, Allegra DP, Nora DT, Wood TF, Foshag LJ, Bilchik AJ
Ann Surg Oncol. 2003;10:52-58
Background: Radiofrequency ablation (RFA) is a promising technique for unresectable hepatic malignancies. We reviewed our RFA experience to identify variables affecting local recurrence.
Methods: Patients undergoing RFA between 1997 and 2001 were reviewed for demographics, tumor size, pathology, diagnosis, recurrence, procedures, survival, and complications.
Results: The 447 unresectable liver tumors were ablated in 198 procedures. The 153 patients averaged 61.9 years of age and 1.25 RFA procedures per patient. Follow-up averaged 11 months. Serial ablations were performed in 28 patients, 8 of whom are without evidence of disease. Tumors were most commonly carcinomas of colorectal, hepatocellular, breast, and melanoma histologies. Colorectal carcinomas and hepatomas individually recurred more frequently than all other tumor types combined in univariate analyses (P =.009 and P =.008, respectively). Patients with multiple tumors ablated recurred significantly more frequently (P =.001). Size was also significant in univariate and multivariate analyses (P =.0032 and <.0001, respectively). Eighteen patients experienced 36 complications.
Conclusions: Size has the highest correlation with local recurrence, but multiple tumors and pathology may also predict local recurrence risk. Large, complex lesions can be safely serially ablated, but because of morbidity and recurrence, RFA should not replace resection as the primary treatment of resectable liver tumors.
Adam R, Hagopian EJ, Linhares M, et al
Arch Surg. 2002;137:1332-1339.
Hypothesis: The complication and success rates in patients treated with either percutaneous cryosurgery (PCS) or percutaneous radiofrequency (PRF) for unresectable hepatic malignancies are similar.
Design: Retrospective study.
Setting: University hospital.
Patients and Methods: Sixty-four patients were treated with either PCS (n = 31) or PRF (n = 33). Patient treatment was based on the random availability of the probes. Tumors were evaluated by a blinded comparison of pretreatment and posttreatment helical computed tomographic scans. All living patients had at least a 6-month follow-up.
Main Outcome Measures: Complication rate, initial treatment success (complete devascularization of the tumor), and local recurrence (tumor revascularization within or at its periphery).
Results: The distribution of tumor types was similar in the 2 groups (P =.76). One patient with cirrhosis died of variceal hemorrhage on day 30 after PCS (mortality, 3.2%), while no mortality was observed after PRF (P =.48). Complications occurred in 9 (29%) of the patients following PCS and in 8 (24%) of the patients following PRF (P =.66). Initial treatment success was comparable in the 2 treatment groups (30 [83%] of 36 tumors following PCS vs 34 [83%] of 41 tumors following PRF). However, local recurrences occurred more frequently after PCS than after PRF (16 [53%] of 30 vs 6 [18%] of 34; P =.003). The higher rate of local recurrence was identified for metastases (10 [71%] of 14 after PCS vs 3 [19%] of 16 after PRF; P =.004), while the difference was not significant for hepatocellular carcinoma (6 [38%] of 16 after PCS vs 3 [17%] of 18 after PRF; P =.25). Multivariate analysis demonstrated that the use of PCS (P =.003) and more than 1 treatment (P =.05) were independent risk factors for local tumor recurrence.
Conclusion: While similar initial treatment success and complication rates are observed following either PCS or PRF, local recurrences occur more frequently following PCS, particularly for metastases.
Chan RP, Asch M, Kachura J, et al
Can Assoc Radiol J. 2002;53:272-278
Objective: To assess the safety and efficacy of radiofrequency ablation (RFA) in the treatment of malignant neoplasms of the liver.
Methods: Sixty-seven patients received RFA for primary or secondary hepatic malignancies. Patients were followed prospectively with computed tomography (CT) scanning to assess for therapeutic response, disease progression and complications.
Results: Eighty-eight lesions were treated, including 57 hepatocellular carcinomas, 28 metastases, 2 cholangiocarcinomas and 1 hepatic plasmacytoma. Mean tumour size was 2.7 cm (range 0.5-6.9 cm). A total of 101 ablations were performed (66 percutaneously, 35 intraoperatively). Over a mean follow-up period of 142 days, results were available for 85 lesions. Local tumour control was achieved for 61 (72%) lesions, but new distant lesions developed in 6 of these cases. Residual disease was present in 20 (23%) lesions, and 4 (5%) lesions developed local recurrence. There were 10 complications, including 1 death in a patient who developed a liver abscess and subsequently died from hepatic failure.
Conclusions: RFA is safe and effective in the treatment of hepatic malignancies. Local tumour control can be achieved in most cases; however, careful surveillance is important for detecting recurrent disease, as well as new lesions distant from the treated site.
Kuvshinoff BW, Ota DM
Surgery. 2002;132:605-611; discussion 611-612
Background: Radiofrequency thermal ablation (RFA) of liver tumors is done by both radiologists and surgeons by using various techniques for a variety of indications. This report describes our initial experience with RFA in 45 patients with hepatic malignancies.
Methods: Patients with primary or secondary hepatic malignancies who were not candidates for resection underwent ultrasound-guided RFA under general anesthesia. End points were recurrence within or adjacent to the ablation zone or new hepatic or extrahepatic lesions. Product limit survival estimates for both ablation site recurrence-free survival and disease-free survival were calculated and compared for tumor size (less than 4 cm or 4 cm or greater), operative approach (percutaneous, laparoscopy, or open), and tumor type (hepatocellular cancer, colorectal cancer, or other metastatic disease).
Results: Patients with hepatocellular cancer (n = 11) and with secondary hepatic malignancies (n = 34) had 84 lesions ablated with a median follow-up of 12 months. Largest ablated tumor size of 4 cm or greater (P <.001) and the percutaneous approach (P <.02) were associated with worse ablation site recurrence-free survival but not overall disease-free survival (P =.06). The 15 patients with colorectal cancer had worse disease-free survival compared with other tumor types (P <.01).
Conclusions: RFA of hepatic malignancies can be done by using a percutaneous, laparoscopic, or open approach. Local control appears superior for tumors less than 4 cm and when an open surgical approach is used. The difficulty in achieving prolonged disease-free survival, especially in colorectal cancer, underscores the need to investigate multimodality approaches that include local ablative techniques. Future RFA studies should consider tumor size, operative technique, and tumor type in trial design.
Mulier S, Mulier P, Ni Y, et al
Br J Surg. 2002;89:1206-1222
Background: Radiofrequency coagulation (RFC) is being promoted as a novel technique with a low morbidity rate in the treatment of liver tumours. The purpose of this study was to assess critically the complication rates of RFC in centres with both large and limited initial experience, and to establish causes and possible means of prevention and treatment.
Methods: This is an exhaustive review of the world literature (articles and abstracts) up to 31 December 2001; 82 independent reports of RFC of liver tumours were analysed.
Results: In total, 3670 patients were treated with percutaneous, laparoscopic or open RFC. The mortality rate was 0.5 per cent. Complications occurred in 8.9 per cent: abdominal bleeding in 1.6 per cent, abdominal infection in 1.1 per cent, biliary tract damage in 1.0 per cent, liver failure in 0.8 per cent, pulmonary complications in 0.8 per cent, dispersive pad skin burn in 0.6 per cent, hepatic vascular damage in 0.6 per cent, visceral damage in 0.5 per cent, cardiac complications in 0.4 per cent, myoglobinaemia or myoglobinuria in 0.2 per cent, renal failure in 0.1 per cent, tumour seeding in 0.2 per cent, coagulopathy in 0.2 per cent, and hormonal complications in 0.1 per cent. The complication rate was 7.2, 9.5, 9.9 and 31.8 per cent after a percutaneous, laparoscopic, simple open and combined open approach respectively. The mortality rate was 0.5, 0, 0 and 4.5 per cent respectively.
Conclusion: The morbidity and mortality of RFC, while low, is higher than previously assumed. With adequate knowledge, many complications are preventable.
Jiang HC, Liu LX, Piao DX, et al
World J Gastroenterol. 2002;8:624-630
Aim: To study local therapeutic efficacy, side effects, and complications of radiofrequency ablation (RFA), which is emerging as a new method for the treatment of patients with hepatocellular carcinoma (HCC) with cirrhosis or chronic hepatitis and metastatic liver cancer.
Methods: Thirty-six patients with primary and secondary liver cancers (21 with primary hepatocellular carcinoma, 12 with colorectal cancer liver metastases and 3 with other malignant liver metastases), which were considered not suitable for curative resection, were include in this study. They were treated either with RFA (RITA2000, Mountain View, California, USA) percutaneously (n=20) or intraoperatively (n=16).The procedures were performed using the ultrasound guidance. The quality of RFA were based on monitoring of equipments and subject feeling of the practitioners. Patients treated with RFA was followed according to clinical findings,radiographic images, and tumor markers.
Results: Thirty-six patients underwent RFA for 48 nodules. RFA was used to treat an average 1.3 lesions per patient, and the median size of treated lesions was 2.5 cm (range, 0.5-9 cm). The average hospital stay was 5.6 days overall (2.8 days for percutaneous cases and 7.9 days for open operations). Seven patients underwent a second RFA procedure (sequential ablations). Sixteen HCC patients with a high level of alpha fetoprotein (AFP) and 9 colorectal cancer liver metastases patients with a high level of serum carcinoembryonic antigen (CEA) have a great reduction benefited from RFA. Four (11.1 %) patients had complications: one skin burn; one postoperative hemorrhage; one cholecystitis and one hepatic abscess associated with percutaneous ablations of a large lesion. There were 4 deaths: 3 patients died from local and system diseases (1 at 7 month, 1 at 9 month, and 1 at 12 month), 1 patients died from cardiovascular shock, but no RFA-related death. At a median follow-up of 10 months (range, 1-24 months), 6 patients (16.7 %) had recurrences at an RFA site, and 20 patients (56.7 %) remained clinically free of disease.
Conclusion: RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of unresectable liver cancers. The rate and severity of complications appear acceptable. However, further study is necessary to assess combination with other therapies, long-term recurrence rates and effect on overall survival.
Machi J, Oishi AJ, Mossing AJ, Furumoto NL, Oishi RH
Surg Laparosc Endosc Percutan Tech. 2002;12:160-164
Ultrasound-guided radiofrequency thermal ablation has been performed for liver tumors by percutaneous, laparoscopic, or open surgical approaches. Each approach has specific advantages and disadvantages. Herein we describe a new technique for hand-assisted laparoscopic ultrasound-guided radiofrequency thermal ablation of liver tumors. A hand-access device is placed at the right or central portion of the abdomen, in addition to standard trocars. A conventional intraoperative ultrasound probe, with an ultrasound guidance system attached, is inserted into the peritoneal cavity together with the surgeon's hand. After pneumoperitoneum is established, an electrode-cannula for thermal ablation is introduced subcostally or intercostally, and advanced into a liver tumor under direct guidance by intraoperative ultrasound. We have used this technique in eight patients with unresectable liver tumors. Precise guidance of the cannula into tumors was possible. All tumors were well ablated. The postoperative recovery of patients was of shorter duration compared with that of an open surgical approach. A hand-assisted laparoscopic ultrasound-guided method has advantages of both laparoscopic and open surgical approaches for radiofrequency thermal ablation treatment of liver tumors. Accurate cannula insertion is possible with the ultrasound guidance system. The hand-assisted laparoscopic approach can become an additional useful technique, particularly as a valuable alternative to an open surgical method, for performing radiofrequency thermal ablation.
Curley SA, Izzo F
Int J Clin Oncol. 2002;7:72-81
The majority of patients with primary of metastatic hepatic tumors are not candidates for resection, because of tumor size, location near major intrahepatic blood vessels precluding a margin-negative resection, multifocality, or inadequate hepatic function related to coexistent cirrhosis. Radiofrequency ablation (RFA) is an evolving technology being used to treat patients with unresectable primary and metastatic hepatic cancers. RFA produces coagulative necrosis of the tumor through local tissue heating. Liver tumors are treated percutaneously, laparoscopically, or during laparotomy, using ultrasonography to identify tumors and to guide placement of the RFA needle electrode. For tumors smaller than 2.0 cm in diameter, one or two deployments of the monopolar multiple-array needle electrode are sufficient to produce complete coagulative necrosis of the tumor. However, with increasing size of the tumor, there is a concomitant increase in the number of deployments of the needle electrode and the overall time necessary to produce complete coagulative necrosis of the tumor. In general, RFA is a safe, well-tolerated, effective treatment for unresectable hepatic malignancies less than 6.0 cm in diameter. Effective treatment of larger tumors awaits the development of more powerful, larger array monopolar and bipolar RFA technologies.
What's new concerning the role of radiofrequency ablation in the treatment of unresectable liver tumors? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Gastroenterology.
Bleicher RJ, Allegra DP, Nora DT, Wood TF, Foshag LJ, Bilchik AJ
Ann Surg Oncol. 2003;10:52-58
Background: Radiofrequency ablation (RFA) is a promising technique for unresectable hepatic malignancies. We reviewed our RFA experience to identify variables affecting local recurrence.
Methods: Patients undergoing RFA between 1997 and 2001 were reviewed for demographics, tumor size, pathology, diagnosis, recurrence, procedures, survival, and complications.
Results: The 447 unresectable liver tumors were ablated in 198 procedures. The 153 patients averaged 61.9 years of age and 1.25 RFA procedures per patient. Follow-up averaged 11 months. Serial ablations were performed in 28 patients, 8 of whom are without evidence of disease. Tumors were most commonly carcinomas of colorectal, hepatocellular, breast, and melanoma histologies. Colorectal carcinomas and hepatomas individually recurred more frequently than all other tumor types combined in univariate analyses (P =.009 and P =.008, respectively). Patients with multiple tumors ablated recurred significantly more frequently (P =.001). Size was also significant in univariate and multivariate analyses (P =.0032 and <.0001, respectively). Eighteen patients experienced 36 complications.
Conclusions: Size has the highest correlation with local recurrence, but multiple tumors and pathology may also predict local recurrence risk. Large, complex lesions can be safely serially ablated, but because of morbidity and recurrence, RFA should not replace resection as the primary treatment of resectable liver tumors.
Adam R, Hagopian EJ, Linhares M, et al
Arch Surg. 2002;137:1332-1339.
Hypothesis: The complication and success rates in patients treated with either percutaneous cryosurgery (PCS) or percutaneous radiofrequency (PRF) for unresectable hepatic malignancies are similar.
Design: Retrospective study.
Setting: University hospital.
Patients and Methods: Sixty-four patients were treated with either PCS (n = 31) or PRF (n = 33). Patient treatment was based on the random availability of the probes. Tumors were evaluated by a blinded comparison of pretreatment and posttreatment helical computed tomographic scans. All living patients had at least a 6-month follow-up.
Main Outcome Measures: Complication rate, initial treatment success (complete devascularization of the tumor), and local recurrence (tumor revascularization within or at its periphery).
Results: The distribution of tumor types was similar in the 2 groups (P =.76). One patient with cirrhosis died of variceal hemorrhage on day 30 after PCS (mortality, 3.2%), while no mortality was observed after PRF (P =.48). Complications occurred in 9 (29%) of the patients following PCS and in 8 (24%) of the patients following PRF (P =.66). Initial treatment success was comparable in the 2 treatment groups (30 [83%] of 36 tumors following PCS vs 34 [83%] of 41 tumors following PRF). However, local recurrences occurred more frequently after PCS than after PRF (16 [53%] of 30 vs 6 [18%] of 34; P =.003). The higher rate of local recurrence was identified for metastases (10 [71%] of 14 after PCS vs 3 [19%] of 16 after PRF; P =.004), while the difference was not significant for hepatocellular carcinoma (6 [38%] of 16 after PCS vs 3 [17%] of 18 after PRF; P =.25). Multivariate analysis demonstrated that the use of PCS (P =.003) and more than 1 treatment (P =.05) were independent risk factors for local tumor recurrence.
Conclusion: While similar initial treatment success and complication rates are observed following either PCS or PRF, local recurrences occur more frequently following PCS, particularly for metastases.
Chan RP, Asch M, Kachura J, et al
Can Assoc Radiol J. 2002;53:272-278
Objective: To assess the safety and efficacy of radiofrequency ablation (RFA) in the treatment of malignant neoplasms of the liver.
Methods: Sixty-seven patients received RFA for primary or secondary hepatic malignancies. Patients were followed prospectively with computed tomography (CT) scanning to assess for therapeutic response, disease progression and complications.
Results: Eighty-eight lesions were treated, including 57 hepatocellular carcinomas, 28 metastases, 2 cholangiocarcinomas and 1 hepatic plasmacytoma. Mean tumour size was 2.7 cm (range 0.5-6.9 cm). A total of 101 ablations were performed (66 percutaneously, 35 intraoperatively). Over a mean follow-up period of 142 days, results were available for 85 lesions. Local tumour control was achieved for 61 (72%) lesions, but new distant lesions developed in 6 of these cases. Residual disease was present in 20 (23%) lesions, and 4 (5%) lesions developed local recurrence. There were 10 complications, including 1 death in a patient who developed a liver abscess and subsequently died from hepatic failure.
Conclusions: RFA is safe and effective in the treatment of hepatic malignancies. Local tumour control can be achieved in most cases; however, careful surveillance is important for detecting recurrent disease, as well as new lesions distant from the treated site.
Kuvshinoff BW, Ota DM
Surgery. 2002;132:605-611; discussion 611-612
Background: Radiofrequency thermal ablation (RFA) of liver tumors is done by both radiologists and surgeons by using various techniques for a variety of indications. This report describes our initial experience with RFA in 45 patients with hepatic malignancies.
Methods: Patients with primary or secondary hepatic malignancies who were not candidates for resection underwent ultrasound-guided RFA under general anesthesia. End points were recurrence within or adjacent to the ablation zone or new hepatic or extrahepatic lesions. Product limit survival estimates for both ablation site recurrence-free survival and disease-free survival were calculated and compared for tumor size (less than 4 cm or 4 cm or greater), operative approach (percutaneous, laparoscopy, or open), and tumor type (hepatocellular cancer, colorectal cancer, or other metastatic disease).
Results: Patients with hepatocellular cancer (n = 11) and with secondary hepatic malignancies (n = 34) had 84 lesions ablated with a median follow-up of 12 months. Largest ablated tumor size of 4 cm or greater (P <.001) and the percutaneous approach (P <.02) were associated with worse ablation site recurrence-free survival but not overall disease-free survival (P =.06). The 15 patients with colorectal cancer had worse disease-free survival compared with other tumor types (P <.01).
Conclusions: RFA of hepatic malignancies can be done by using a percutaneous, laparoscopic, or open approach. Local control appears superior for tumors less than 4 cm and when an open surgical approach is used. The difficulty in achieving prolonged disease-free survival, especially in colorectal cancer, underscores the need to investigate multimodality approaches that include local ablative techniques. Future RFA studies should consider tumor size, operative technique, and tumor type in trial design.
Mulier S, Mulier P, Ni Y, et al
Br J Surg. 2002;89:1206-1222
Background: Radiofrequency coagulation (RFC) is being promoted as a novel technique with a low morbidity rate in the treatment of liver tumours. The purpose of this study was to assess critically the complication rates of RFC in centres with both large and limited initial experience, and to establish causes and possible means of prevention and treatment.
Methods: This is an exhaustive review of the world literature (articles and abstracts) up to 31 December 2001; 82 independent reports of RFC of liver tumours were analysed.
Results: In total, 3670 patients were treated with percutaneous, laparoscopic or open RFC. The mortality rate was 0.5 per cent. Complications occurred in 8.9 per cent: abdominal bleeding in 1.6 per cent, abdominal infection in 1.1 per cent, biliary tract damage in 1.0 per cent, liver failure in 0.8 per cent, pulmonary complications in 0.8 per cent, dispersive pad skin burn in 0.6 per cent, hepatic vascular damage in 0.6 per cent, visceral damage in 0.5 per cent, cardiac complications in 0.4 per cent, myoglobinaemia or myoglobinuria in 0.2 per cent, renal failure in 0.1 per cent, tumour seeding in 0.2 per cent, coagulopathy in 0.2 per cent, and hormonal complications in 0.1 per cent. The complication rate was 7.2, 9.5, 9.9 and 31.8 per cent after a percutaneous, laparoscopic, simple open and combined open approach respectively. The mortality rate was 0.5, 0, 0 and 4.5 per cent respectively.
Conclusion: The morbidity and mortality of RFC, while low, is higher than previously assumed. With adequate knowledge, many complications are preventable.
Jiang HC, Liu LX, Piao DX, et al
World J Gastroenterol. 2002;8:624-630
Aim: To study local therapeutic efficacy, side effects, and complications of radiofrequency ablation (RFA), which is emerging as a new method for the treatment of patients with hepatocellular carcinoma (HCC) with cirrhosis or chronic hepatitis and metastatic liver cancer.
Methods: Thirty-six patients with primary and secondary liver cancers (21 with primary hepatocellular carcinoma, 12 with colorectal cancer liver metastases and 3 with other malignant liver metastases), which were considered not suitable for curative resection, were include in this study. They were treated either with RFA (RITA2000, Mountain View, California, USA) percutaneously (n=20) or intraoperatively (n=16).The procedures were performed using the ultrasound guidance. The quality of RFA were based on monitoring of equipments and subject feeling of the practitioners. Patients treated with RFA was followed according to clinical findings,radiographic images, and tumor markers.
Results: Thirty-six patients underwent RFA for 48 nodules. RFA was used to treat an average 1.3 lesions per patient, and the median size of treated lesions was 2.5 cm (range, 0.5-9 cm). The average hospital stay was 5.6 days overall (2.8 days for percutaneous cases and 7.9 days for open operations). Seven patients underwent a second RFA procedure (sequential ablations). Sixteen HCC patients with a high level of alpha fetoprotein (AFP) and 9 colorectal cancer liver metastases patients with a high level of serum carcinoembryonic antigen (CEA) have a great reduction benefited from RFA. Four (11.1 %) patients had complications: one skin burn; one postoperative hemorrhage; one cholecystitis and one hepatic abscess associated with percutaneous ablations of a large lesion. There were 4 deaths: 3 patients died from local and system diseases (1 at 7 month, 1 at 9 month, and 1 at 12 month), 1 patients died from cardiovascular shock, but no RFA-related death. At a median follow-up of 10 months (range, 1-24 months), 6 patients (16.7 %) had recurrences at an RFA site, and 20 patients (56.7 %) remained clinically free of disease.
Conclusion: RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of unresectable liver cancers. The rate and severity of complications appear acceptable. However, further study is necessary to assess combination with other therapies, long-term recurrence rates and effect on overall survival.
Machi J, Oishi AJ, Mossing AJ, Furumoto NL, Oishi RH
Surg Laparosc Endosc Percutan Tech. 2002;12:160-164
Ultrasound-guided radiofrequency thermal ablation has been performed for liver tumors by percutaneous, laparoscopic, or open surgical approaches. Each approach has specific advantages and disadvantages. Herein we describe a new technique for hand-assisted laparoscopic ultrasound-guided radiofrequency thermal ablation of liver tumors. A hand-access device is placed at the right or central portion of the abdomen, in addition to standard trocars. A conventional intraoperative ultrasound probe, with an ultrasound guidance system attached, is inserted into the peritoneal cavity together with the surgeon's hand. After pneumoperitoneum is established, an electrode-cannula for thermal ablation is introduced subcostally or intercostally, and advanced into a liver tumor under direct guidance by intraoperative ultrasound. We have used this technique in eight patients with unresectable liver tumors. Precise guidance of the cannula into tumors was possible. All tumors were well ablated. The postoperative recovery of patients was of shorter duration compared with that of an open surgical approach. A hand-assisted laparoscopic ultrasound-guided method has advantages of both laparoscopic and open surgical approaches for radiofrequency thermal ablation treatment of liver tumors. Accurate cannula insertion is possible with the ultrasound guidance system. The hand-assisted laparoscopic approach can become an additional useful technique, particularly as a valuable alternative to an open surgical method, for performing radiofrequency thermal ablation.
Curley SA, Izzo F
Int J Clin Oncol. 2002;7:72-81
The majority of patients with primary of metastatic hepatic tumors are not candidates for resection, because of tumor size, location near major intrahepatic blood vessels precluding a margin-negative resection, multifocality, or inadequate hepatic function related to coexistent cirrhosis. Radiofrequency ablation (RFA) is an evolving technology being used to treat patients with unresectable primary and metastatic hepatic cancers. RFA produces coagulative necrosis of the tumor through local tissue heating. Liver tumors are treated percutaneously, laparoscopically, or during laparotomy, using ultrasonography to identify tumors and to guide placement of the RFA needle electrode. For tumors smaller than 2.0 cm in diameter, one or two deployments of the monopolar multiple-array needle electrode are sufficient to produce complete coagulative necrosis of the tumor. However, with increasing size of the tumor, there is a concomitant increase in the number of deployments of the needle electrode and the overall time necessary to produce complete coagulative necrosis of the tumor. In general, RFA is a safe, well-tolerated, effective treatment for unresectable hepatic malignancies less than 6.0 cm in diameter. Effective treatment of larger tumors awaits the development of more powerful, larger array monopolar and bipolar RFA technologies.
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