Combined Ethanol Injection Therapy and Radiofrequency Ablation Therapy in Percutaneous Treatment of Hepatocellular Carcinoma Larger than 4 cm

Background Optimal treatment of large-sized hepatocellular carcinoma (HCC) is still debated, because percutaneous ablation therapies alone do not always achieve complete necrosis. Objective To report our experience in the treatment of patients with HCC larger than 4 cm in diameter by combined percutaneous ethanol injection and radiofrequency thermal ablation. Methods In a 5-year period there were 40 consecutive patients meeting the inclusion criteria (24 men and 16 women; age range 41–72 years, mean 58 years). These subjects had a single HCC larger than 4 cm. Twelve subjects also had one or two additional nodules smaller than 4 cm (mean 1.2 nodules per patient). Patients were submitted to one to three sessions consisting of ethanol injection at two opposite tumor poles (mean 12 ml) and then of radiofrequency application through one or two electrodes placed at the tumor center (mean treatment duration 30 min). Results Complete necrosis was obtained in all cases with one to three sessions (mean 1.3 sessions per patient). All patients experienced pain and fever but one only subject had a major complication requiring treatment (abscess development and fistulization). Overall follow-up was 7–69 months. Two patients showed local recurrence and 9 developed new etherotopic HCC nodules. Seven subjects died during follow-up while 33 were free from recurrence 8–69 months after treatment. Conclusion A combination of ethanol injection and radiofrequency ablation is effective in the treatment of large HCC.     

Radiofrequency thermal ablation with expandable needle of focal liver malignancies: complication report

The aim of this study was to describe type and rate of complications in a series of patients with liver tumors treated by the radiofrequency (RF) expandable system. A total of 166 patients, 114 with hepatocellular carcinoma (HCC; 92 small HCC, 22 large) and 52 with liver metastasis, were treated by the percutaneous RF expandable system. In large HCCs, RF ablation was performed after tumor ischemia (TAE or balloon stop flow of the hepatic artery). Major complications were those that delayed hospital discharge, with or without additional medical procedures or treatments. Minor complications did not require an additional hospital stay. No deaths occurred. Among 151 patients followed, there were 7 (4.6%) early major complications—severe pain with session interruption in 3 cases, capsular necrosis in 1 case, 1 abdominal wall necrosis, 1 dorsal burning, 1 peritoneal hemorrhage—and 3 (1.9%) delayed major complications: sterile fluid collection at the site of the treated tumor in 2 cases and cutaneous seeding in 1 case. There were 49 (32.5%) minor complications. The complication rate is similar to that observed after percutaneous alcohol injection (PEI). With the cooled system, the complication rate is seemingly lower but that may well be due to a different definition of major complications. The seeding rate after expandable system ablation is lower than after PEI. It is the same as or lower than that in other series of patients treated by the cooled system.     

Recurrent hepatocellular carcinoma: percutaneous radiofrequency ablation after hepatectomy

PURPOSE: To evaluate the therapeutic efficacy and safety of percutaneous radiofrequency (RF) ablation for recurrent hepatocellular carcinoma (HCC) in the liver after hepatectomy. MATERIALS AND METHODS: Forty-five patients with 53 recurrent HCC tumors in the liver underwent percutaneous RF ablation with ultrasonographic guidance. All patients had a history of hepatic resection for HCC. The mean diameter of recurrent tumors was 2.1 cm (range, 0.8-4.0 cm). All patients were followed up for at least 10 months after ablation (range, 10-40 months; mean, 23 months). Therapeutic efficacy and complications were evaluated with multiphase helical computed tomography (CT) at regular follow-up visits. Overall and disease-free survival rates were calculated. RESULTS: At follow-up CT after initial RF ablation, 11 (21%) of 53 ablated HCC tumor sites showed residual tumor or local tumor progression. After additional RF ablation, complete ablation of 46 (87%) of 53 tumors was attained. Also at initial follow-up CT, before either additional RF ablation or other treatment was performed, 21 (47%) of 45 patients were found to have 41 new HCC tumors at other liver sites. Of these, nine tumors in eight patients were treatable with a second application of RF ablation. Overall survival rates at 1, 2, and 3 years were 82%, 72%, and 54%, respectively. No deaths or complications requiring further treatment occurred as a result of RF ablation. CONCLUSION: Percutaneous RF ablation is an effective and safe method for treating recurrent HCC in the liver after hepatectomy, with a good overall patient survival rate.     

Small hepatocellular carcinoma: comparison of radio-frequency ablation and percutaneous microwave coagulation therapy

PURPOSE: To evaluate the effectiveness of radio-frequency (RF) ablation and percutaneous microwave coagulation (PMC) for treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventy-two patients with 94 HCC nodules were randomly assigned to RF ablation and PMC groups. Thirty-six patients with 48 nodules were treated with RF ablation, and 36 patients with 46 nodules were treated with PMC. Therapeutic effect, residual foci of untreated disease, and complications of RF ablation and PMC were prospectively evaluated with statistical analyses. RESULTS: The number of treatment sessions per nodule was significantly lower in the RF ablation group than in the PMC group (1.1 vs 2.4; P <.001). Complete therapeutic effect was achieved in 46 (96%) of 48 nodules treated with RF ablation and in 41 (89%) of 46 nodules treated with PMC (P =.26). Major complications occurred in one patient treated with RF ablation and in four patients treated with PMC (P =.36). During follow-up (range, 6-27 months), residual foci of untreated disease were seen in four of 48 nodules treated with RF ablation and in eight of 46 nodules treated with PMC. No significant difference in rates of residual foci of untreated disease was noted (P =.20, log-rank test). CONCLUSION: RF ablation and PMC thus far have had equivalent therapeutic effects, complication rates, and rates of residual foci of untreated disease. However, RF tumor ablation can be achieved with fewer sessions.     

Treatment strategy to optimize radiofrequency ablation for liver malignancies

PURPOSE: The purposes of this study were to investigate a treatment strategy to increase liver tumor necrosis and minimize complications with ultrasound-guided percutaneous radiofrequency (RF) ablation and to evaluate its therapeutic efficacy. MATERIALS AND METHODS: A total of 332 patients with 503 liver malignancies underwent RF ablation according to a mathematical protocol with adjunctive measures. In the 332 patients, 205 had 308 hepatocellular carcinomas (HCCs) with a mean largest diameter of 4.1 cm and 127 had 195 metastatic liver carcinomas (MLCs) with a mean largest diameter of 3.9 cm. In patients with HCC, 60 (29.3%) had stage I/II disease and 145 (70.7%) had stage III/IV disease. Depending on tumor size, shape, and location, a defined treatment strategy was adopted that consisted of a mathematical protocol, an individualized protocol, and adjunctive measures. The mathematical protocol was followed for tumors larger than 3.5 cm. The individualized protocol was used for tumors located adjacent to the diaphragm, gastrointestinal tract, or gallbladder. Some adjunctive measures such as supplementary fine needle localization, local saline solution injection, and feeding vessel ablation were used to deal with different features of these liver tumors. Patients were followed regularly to assess treatment efficiency, and the tumor was considered to have early complete necrosis if no viability was found on enhanced computed tomography 1 month after RF ablation. RESULTS: In this series, the early necrosis rates were 95.8% for HCC (295 of 308 tumors), 94.9% for MLC (185 of 195 tumors), 91.3% for tumors larger than 3.5 cm (189 of 207 tumors), 90.7% for tumors near the gastrointestinal tract (49 of 54 tumors), 91.5% for tumors near the diaphragm (86 of 94 tumors), and 90.6% for tumors near the gallbladder (48 of 53 tumors). The local recurrence rates were 10.7% for HCC (33 of 308 tumors) and 14.9% for MLC (29 of 195 tumors). The 1-, 2-, and 3-year overall survival rates were 89.6%, 69.4%, and 59.6%, respectively, for HCC and 80.3%, 52.8%, and 30.9%, respectively, for MLC. The 1-, 2-, and 3-year survival rates in 60 patients with stage I/II HCC were 93.7%, 87.1%, and 76.2%, respectively. The incidence of major complications was 1.4% (eight of 574 sessions), which included of three hemorrhages, four injuries to adjacent structures, and one case of needle tract seeding. CONCLUSION: In RF ablation of hepatic tumors, application of a proper protocol and adjunctive measures play important roles in improving tumor necrosis rate and minimizing potential complications.     

The combined effect of radiofrequency and ethanol ablation in the management of large hepatocellular carcinoma

Only a small percentage of patients with large hepatocellular carcinoma (HCC) may benefit out of surgical resection. Thus, most of these patients are in need of a form of local control, such as ethanol ablation, transarterial chemoembolization (TACE), radiofrequency thermal ablation (RF), or laser induced thermotherapy (LITT). The purpose of this study was to assess the short-term effect of sequential RF and ethanol ablation in the management of large HCC (>5 cm). Our series included 40 patients with large HCC tumors (>5 cm in diameter). We adopted a protocol of overlapping RF applications, followed by repeated ethanol ablation sessions. Our results showed that the volume of tumor coagulative necrosis initially induced by RF has significantly risen after adjuvant ethanol ablation sessions (P < 0.001). Patients who achieved complete tumor necrosis after RF ablation were 52.5% of the series. This percent has jumped to 80% of the series at the end of the protocol. This indicates that such combined protocol is more effective than RF alone. Besides, it is valuable in reducing the number of RF sessions.     

Percutaneous radio-frequency thermal ablation of nonresectable hepatocellular carcinoma after occlusion of tumor blood supply

PURPOSE: To evaluate the usefulness of percutaneous radio-frequency (RF) thermal ablation of nonresectable hepatocellular carcinoma (HCC) after occlusion of the tumor arterial supply. MATERIALS AND METHODS: Sixty-two patients with cirrhosis and biopsy-proved HCC underwent RF ablation after interruption of the tumor arterial supply by means of occlusion of either the hepatic artery with a balloon catheter (40 patients) or the feeding arteries with gelatin sponge particles (22 patients). RESULTS: After a single RF procedure in 56 patients and after two procedures in six patients, spiral computed tomography (CT) demonstrated a nonenhancing area corresponding in shape to the previously identified HCC, which was suggestive of complete necrosis. No major complications occurred. Two patients subsequently underwent surgical resection; the remaining 60 patients were followed up with spiral CT. During a mean follow-up of 12.1 months, 11 HCC nodules showed areas of local progression; 49 were identified as nonenhancing areas with a 40%-75% reduction in maximum diameter. The 1-year estimate of failure risk was 19% for local recurrence and 45% for overall intrahepatic recurrence. The estimated 1-year survival was 87%. Histopathologic analysis of one autopsy and two surgical specimens revealed more than 90% necrosis in one specimen and 100% necrosis in two. CONCLUSION: HCC nodules 3.5-8.5 cm in diameter can be ablated in one or two RF sessions after occlusion of the tumor arterial supply.     

Percutaneous radiofrequency ablation of renal tumors: midterm results in 16 patients

PURPOSE: To evaluate the outcome of 16 patients after percutaneous radiofrequency ablation of renal tumors. MATERIALS AND METHODS: Sixteen patients (nine women, seven men; mean age, 61+/-9 years) with 24 unresectable renal tumors (mean volume, 4.3+/-4.3 cm3) underwent CT-guided (n=20) or MR imaging-guided (n=4) percutaneous radiofrequency ablation using an expandable electrode (Starburst XL, RITA Medical Systems, Mountain View, CA) with a 150-W generator. The initial follow-up imaging was performed within 1-30 days after RF ablation, then at 3-6 month intervals using either CT or MRI. Residual tumor volume and coagulation necrosis was assessed, and statistical correlation tests were obtained to determine the strength of the relationship between necrosis volume and number of ablations. RESULTS: Overall, 97 overlapping RF ablations were performed (mean, 3.5+/-1.5 ablations per tumor) during 24 sessions. Five or more RF ablations per tumor created significant larger necrosis volumes than 1-2 (p=.034) or 3-4 ablations (p=.020). A complete ablation was achieved in 20/24 tumors (primary technical success, 83%; mean volume of coagulation necrosis: 10.2+/-7.2 cm3). Three of four residual tumors were retreated and showed complete necrosis thereafter. Three major complications (one percuatneous urinary fistula and two ureteral strictures) were observed after RF ablation. No further clinically relevant complications were observed and renal function remained stable. During a mean follow-up of 11.2 months (range, 0.2-31.5), 15/16 patients (94%) were alive. Only one patient had evidence of local recurrent tumor. CONCLUSION: The midterm results of percutaneous RF ablation for renal tumors are promising and show that RF ablation is well-suited to preserve renal function.     

Frequency and Risk Factors of Various Complications After Computed Tomography–Guided Radiofrequency Ablation of Lung Tumors

Objective To retrospectively determine the frequency and risk factors of various side effects and complications after percutaneous computed tomography–guided radiofrequency (RF) ablation of lung tumors. Methods We reviewed and analyzed records of 112 treatment sessions in 57 of our patients (45 men and 12 women) with unresectable lung tumors treated by ablation. Risk factors, including sex, age, tumor diameter, tumor location, history of surgery, presence of pulmonary emphysema, electrode gauge, array diameter, patient position, maximum power output, ablation time, and minimum impedance during ablation, were analyzed using univariate and multivariate analyses. Results Total rates of side effects and minor and major complications occurred in 17%, 50%, and 8% of treatment sessions, respectively. Side effects, including pain during ablation (46% of sessions) and pleural effusion (13% of sessions), occurred with RF ablation. Minor complications, including pneumothorax not requiring chest tube drainage (30% of sessions), subcutaneous emphysema (16% of sessions), and hemoptysis (9% of sessions) also occurred after the procedure. Regarding major complications, three patients developed fever >38.5°C; three patients developed abscesses; two patients developed pneumothorax requiring chest tube insertion; and one patient had air embolism and was discharged without neurologic deficit. Univariate and multivariate analyses suggested that a lesion located ≤1 cm of the chest wall was significantly related to pain (p < 0.01, hazard index 5.76). Risk factors for pneumothorax increased significantly with previous pulmonary surgery (p < 0.05, hazard index 6.1) and presence of emphysema (p <0.01, hazard index 13.6). Conclusion The total complication rate for all treatment sessions was 58%, and 25% of patients did not have any complications after RF ablation. Although major complications can occur, RF ablation of lung tumors can be considered a safe and minimally invasive procedure.     

Large infiltrative hepatocellular carcinomas: treatment with percutaneous intraarterial ethanol injection alone or in combination with conventional percutaneous ethanol injection

PURPOSE: To retrospectively evaluate patients' tolerance and the effectiveness of percutaneous intraarterial ethanol injection (PIAEI), alone or combined with conventional percutaneous ethanol injection (PEI), for treatment of advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Neither institutional review board approval nor informed consent was required for this retrospective study; however, all patients had given their consent to be treated with PIAEI. Fourteen men and four women with cirrhosis and HCC who were ineligible for conventional curative treatment (largest tumor diameter, 35-90 mm; mean, 52 mm +/- 16 [standard deviation]) and whose supplying arteries were visible on computed tomographic (CT) and color Doppler ultrasonographic (US) images were treated with US-guided PIAEI-either alone or combined with PEI. Twelve patients had infiltrative tumors, and six had nodular tumors. Four patients had portal venous tumor involvement. Tumor necrosis and recurrence were evaluated with CT, and 1- and 2-year survival rates were evaluated with Kaplan-Meier analysis. RESULTS: In four patients, the main tumor was treated with PIAEI only, and in 14 patients, the main tumor was treated with combined PIAEI and PEI. One patient died of myocardial infarction before CT evaluation. Tumor necrosis was complete in 15 (88%) and incomplete in two (12%) of 17 patients. Results of subsequent surgery performed in three patients confirmed the radiologic findings: complete tumor necrosis in two patients and incomplete necrosis in one patient. Two severe PIAEI-related complications occurred: liver abscess, which resolved, and fatal acute pancreatitis. During the follow-up period (mean, 15 months +/- 6.7), six patients died owing to recurrent HCC, and 10 patients were alive with no detectable tumor after a mean follow-up period of 18 months +/- 11. One- and 2-year survival rates were 76.6% and 44.5%, respectively. CONCLUSION: For patients with advanced HCC who are ineligible for other curative options, PIAEI could be an effective treatment, despite the associated risk of severe complications.     

Percutaneous radiofrequency ablation of small hepatocellular carcinoma: long-term results

The aim of this study was to evaluate the effectiveness and the safety of percutaneous radiofrequency (RF) thermal ablation of hepatocellular carcinoma (HCC) in 88 patients with a long follow-up, and to compare conventional electrodes and expandable electrodes. Eighty-eight patients with 101 hepatocellular carcinoma nodules (≤ 3.5 cm in diameter) underwent RF thermal ablation by means of either conventional electrodes or an expandable electrode. Therapeutic efficacy was evaluated with dynamic contrast CT, serum α-feto protein level, US examination at the end of the treatment, and during follow-up. Complete necrosis was obtained in all tumor nodules in a mean number of 3.3 sessions (tumor treated by conventional electrodes) or 1.5 sessions (tumor treated by expandable electrode). The mean follow-up was 34 months; overall survival rate was 33 % at 5 years. Disease-free survival at 5 years was 3 %; local recurrence rate was 29 % in patients treated with conventional electrodes; 14 % in patients treated with the expandable electrode. Two major complications and 14 minor complications were observed. Radiofrequency thermal ablation in small HCC is very effective with a low percentage of major complications. The use of an expandable electrode substantially reduced the number of treatment sessions but did not modify the overall survival rate and the disease-free survival rate. Received: 7 January 2000 Revised: 19 July 2000 Accepted: 11 August 2000     

Intrahepatic tumor recurrence after partial hepatectomy: value of percutaneous radiofrequency ablation

PURPOSE: To determine the risks and benefits of percutaneous radiofrequency (RF) ablation of recurrent hepatic tumors in patients who have undergone hepatic resection. MATERIALS AND METHODS: Retrospective review of the institutional RF ablation database yielded 35 patients with recurrent hepatic tumor after hepatectomy. Sixty-one recurrent hepatic tumors (mean diameter +/- SD, 1.7 +/- 1.1 cm; range, 0.5-5.3 cm) were ablated percutaneously under sonographic guidance or combined guidance with sonographic and fluoroscopic computed tomography (CT). Follow-up CT, magnetic resonance imaging, or both were used for assessment of the primary and secondary therapeutic effectiveness rate and failure of RF ablation. Patients' survival status was determined by contacting the primary care physician or searching the Social Security Death Index. RESULTS: Complete ablation was accomplished in 54 of 61 hepatic tumors (primary therapeutic effectiveness rate, 88.5%). During a mean follow-up time of 18 months (range, 1-65 months), 14.8% of the tumors (n = 9) were incompletely ablated. Three of the nine incompletely ablated tumors were treated with a second RF ablation, all three of which failed (secondary therapeutic effectiveness rate, 0%). Distant intrahepatic tumor progression appeared in 23 of 35 patients (65.7%). One major complication (2.1%, one of 48 sessions) and eight minor complications (16.7%, eight of 48 sessions) were reported. The major complication was hepatic abscess formation. The overall survival rates for all patients at 1, 2, and 3 years were 76%, 68%, and 45%, respectively. For patients with metastases from colorectal cancer (n = 14), the overall survival rates were 72%, 60%, and 60% at 1, 2, and 3 years, respectively; and for patients with hepatocellular carcinoma (n = 8), the overall survival rates were 72%, 58%, and 44% at 1, 2, and 3 years, respectively. CONCLUSION: Percutaneous RF ablation offers a safe and effective treatment option for recurrent hepatic tumors after previous partial hepatectomy.     

Local-regional treatment of hepatocellular carcinoma

Local-regional treatments play a key role in the management of hepatocellular carcinoma (HCC). Image-guided tumor ablation is recommended in patients with early-stage HCC when surgical options are precluded and can replace resection in selected patients. Radiofrequency (RF) ablation has shown superior anticancer effects and greater survival benefit with respect to the seminal percutaneous technique, ethanol injection, in meta-analyses of randomized controlled trials and is currently established as the standard method for local tumor treatment. Novel thermal and nonthermal techniques for tumor ablation, including microwave ablation and irreversible electroporation, seem to have potential to overcome the limitations of RF ablation and warrant further clinical investigation. Transcatheter arterial chemoembolization (TACE) is the standard of care for patients with asymptomatic noninvasive multinodular tumors in intermediate-stage disease. Embolic microspheres that have the ability to release a drug in a controlled and sustained fashion have been shown to substantially increase the safety and efficacy of TACE in comparison to conventional ethiodized oil-based regimens. The available data for radioembolization with yttrium 90 suggest that this is a potential new option for patients with HCC, and future studies should be devoted to assessments of the role of radioembolization in the treatment algorithm for HCC.     

Percutaneous radiofrequency ablation of renal tumors: technique, complications, and outcomes

PURPOSE: To report the safety, technical success, and effectiveness of percutaneous radiofrequency (RF) ablation for renal tumors. MATERIALS AND METHODS: The authors retrospectively reviewed the medical records and imaging studies of 29 consecutive patients (18 men, 11 women; mean age, 65 +/- 2.62 years) with 30 renal tumors (mean diameter, 3.5 +/- 0.24 cm) who underwent percutaneous RF ablation at their institution from September 2001 to March 2004. All procedures were performed with computed tomography guidance with general anesthesia, and all patients were admitted to the hospital for overnight observation. Technical success, complications, and their management were recorded. Technique effectiveness was assessed by imaging and clinical follow up. RESULTS: Overall, 88 overlapping ablations were performed (mean, 2.6 +/- 0.16 ablations per tumor per session) in 34 sessions. There were four major complications (12%). Three patients had gross hematuria and urinary obstruction, all were successfully treated. One patient had persistent anterior abdominal wall weakness. There were also two minor complications (6%) without significant clinical sequelae. One patient had gross hematuria which resolved spontaneously, another patient had transient paresthesia of the anterior abdominal wall. There were no significant changes in renal function after RF ablation. The intent of RF ablation was eradication of the primary tumor in 27 patients and treatment of gross hematuria in the other two. Technical success was achieved in all cases. Follow-up images were available for 26 patients. The primary tumor was completely ablated in 23 of 24 patients (96%) in whom eradication of the primary tumor was attempted (follow up period: mean, 10 months, median 7 months). The two patients treated for hematuria remained asymptomatic for 6 and 27 months each. CONCLUSION: Percutaneous RF ablation for renal tumors is safe and well tolerated. High technical success rates are expected. Early reports of the technique's effectiveness are promising.     

Cholangitis and liver abscess after percutaneous ablation therapy for liver tumors: incidence and risk factors

PURPOSE: To determine the risk factors of cholangitis and liver abscess occurring after percutaneous ablation therapy for liver tumors. MATERIALS AND METHODS: Between October 1995 and September 2002, 358 patients with 455 liver tumors underwent a total of 683 ablation procedures, such as percutaneous ethanol injection (PEI), percutaneous microwave coagulation (PMC), and radiofrequency (RF) ablation therapy. With a retrospective review of medical records, the rates and outcomes of cholangitis and/or liver abscess occurring after ablation therapy were evaluated. The relationship between cholangitis and/or liver abscess and multiple variables (age, disease, Child-Pugh class, size of nodules, multiplicity of nodules, history of transcatheter arterial embolization, presence of bilioenteric anastomosis, and lack of prophylactic antibiotics administration) were statistically analyzed. RESULTS: Cholangitis and/or liver abscess occurred in 10 sessions (1.5%) in 10 patients: six sessions after PEI, three sessions after PMC, and one session after RF ablation. Both cholangitis and liver abscess were noted in seven sessions, cholangitis was noted in two, and liver abscess was noted in one. Six patients recovered, but two developed recurrent cholangitis and liver abscess, one developed lung abscess complicated with liver abscess, and one died of septic shock associated with cholangitis. On stepwise regression analysis, bilioenteric anastomosis was the sole significant predictor of cholangitis and/or liver abscess formation (P <.001; odds ratio = 36.4; 95% CI = 9.67-136.9). CONCLUSION: Bilioenteric anastomosis strongly correlated with the development of cholangitis and/or liver abscess after percutaneous ablation therapy. Close posttreatment attention should be paid to this subgroup of patients.     

Efficacy and safety of radiofrequency ablation of hepatocellular carcinoma in the hepatic dome with the CT-guided extrathoracic transhepatic approach

PURPOSE: The purpose of this study was to determine the efficacy and safety of radiofrequency (RF) ablation for the treatment of hepatocellular carcinoma (HCC) in the hepatic dome with CT-guided extrathoracic transhepatic approach. MATERIALS AND METHODS: Fifteen patients with 15 HCCs (size range: 0.8-4 cm, mean size: 1.8 cm) in the hepatic dome were treated by RF ablation using cooled-tip electrodes and with CT-guided extrathoracic transhepatic approach. Therapeutic response of the tumor to RF ablation and procedure-related complications including hepatic injury, hemoperitoneum, and thermal injury of diaphragm were evaluated. RESULTS: The average number of needle punctures to ensure the correct needle position in the targeted tumor was 3.7 (range: 1-6 punctures). The average ablation time was 14.7 min (range: 8-25 min). Complete necrosis without marginal recurrence after at least 13-month follow-up was attained in 13 tumors (86.7%). There were no major complications related to the procedures. Six patients had shoulder pain that lasted three days to two weeks after the procedures and their symptoms were resolved with conservative treatment. CONCLUSIONS: RF ablation using CT-guided extrathoracic transhepatic approach is an effective and safe technique for the treatment of HCC in the hepatic dome.     

Sonazoid-enhanced sonography for guiding radiofrequency ablation for hepatocellular carcinoma: better tumor visualization by Kupffer-phase imaging and vascular-phase imaging after reinjection

Purpose  The purpose of this study was to assess the usefulness of contrast harmonic sonography with a newly developed sonographic contrast agent as a means of guidance for percutaneous radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). Materials and methods  A total of 52 consecutive HCC lesions in 42 patients with HCC who underwent percutaneous RF ablation were included in this study. Altogether, 40 lesions in 35 patients were untreated HCC, and 12 lesions in 7 patients were local tumor progression of an HCC that had already been treated by other methods. We investigated tumors by Kupffer-phase imaging and vascular-phase imaging after reinjection. We performed RF ablation guided by Sonazoid-enhanced sonography using Kupffer-phase imaging and vascular-phase imaging after reinjection. Results  Conventional sonography identified 30 (57%) of 52 HCCs, whereas Sonazoid-enhanced sonography detected 50 (96%) of 52 HCCs (P < 0.01, McNemar’s χ² test). Complete ablation was achieved at a single session in 48 of 50 tumors. Conclusion  Sonazoid-enhanced sonography is a useful technique for guiding RF ablation of HCCs, even when treating local progression of a previously treated HCC.     

Image-Guided Percutaneous Radiofrequency Ablation of Central Renal Cell Carcinoma: Assessment of Clinical Efficacy and Safety in 31 Tumors

Purpose

To assess clinical efficacy and safety of image-guided percutaneous radiofrequency (RF) ablation of central renal cell carcinoma with adjunctive pyeloperfusion.

Risk factors for occurrence of local tumor progression after percutaneous radiofrequency ablation for lung neoplasms

PURPOSE: To examine the characteristics of lung tumors for which radiofrequency (RF) ablation therapy is effective, and to determine what RF ablation parameters are effective for obtaining complete coagulation of the entire ablation zone with a single RF ablation session. MATERIALS AND METHODS: Computed tomography (CT)-guided RF ablation of lung tumors was performed on 82 lesions in 34 patients between April 2003 and May 2005. Tumor characteristics and ablation parameters, including tumor size, location, and depth, and ablation duration, power deployed during ablation, and temperatures achieved were analyzed with regard to local tumor progression. RESULTS: In all, 103 RF ablation sessions were performed on 82 tumors. As a procedure-related complication, pneumothorax occurred in 27 procedures. During the mean follow-up period of 10 months (range, 6-28 months), local tumor progression occurred in 18 (22.0%) of the 82 ablated tumors (3 months after RF ablation in 10, 6 months after RF ablation in 5, 9 months after RF ablation in 1, and 12 months after RF ablation in 2). Mean local progression-free duration was 8.7 +/- 4.5 months (range, 3-28 months). The frequency of local tumor progression was significantly correlated with size, whereas other variables had no statistical association. In tumors with a diameter > or =2.5 cm, only the period of ablation during the initial session was significantly correlated with subsequent local tumor progression (P = 0.000002, chi-square test). CONCLUSION: A long duration of RF ablation is desirable for large lung tumors. The success of RF ablation is dependent upon tumor size. RF ablation treatment is most effective for lesions < 2.5 cm.     

Radiofrequency ablation combined with chemoembolization for the treatment of hepatocellular carcinomas 5 cm or smaller: risk factors for local tumor progression

PURPOSE: To investigate the risk factors for local tumor progression after radiofrequency (RF) ablation combined with chemoembolization for the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 255 HCC lesions 5 cm or less in maximum diameter were treated by RF ablation in 173 patients within 2 weeks after chemoembolization was performed. Therapeutic response was evaluated by contrast medium-enhanced computed tomography studies. The disappearance of tumor enhancement was considered to indicate complete necrosis. Local tumor progression was defined by the appearance of enhanced tumor adjacent to the zone of ablation. The risk factors for local tumor progression after RF ablation were retrospectively assessed by univariate and multivariate analyses. RESULTS: All tumors showed complete necrosis after RF ablation. Local tumor progression was found in 18 of the 255 lesions (7%) during a mean follow-up period of 23 months (range, 1-63 months). The cumulative local tumor progression rate was 12% at 5 years. Larger tumor (3.1-5 cm), infiltrating tumor, and previous treatments were found to increase the risk of local tumor progression in univariate and multivariate analyses. CONCLUSIONS: The combination of chemoembolization with RF ablation is an effective treatment to control HCC lesions. The factors identified in the present study may help to predict the therapeutic response.