Radiofrequency ablation of hepatocellular carcinoma: treatment success as defined by histologic examination of the explanted liver

PURPOSE: To retrospectively evaluate the effectiveness of radiofrequency (RF) ablation of hepatocellular carcinoma (HCC) by using histologic examination of the explanted liver. MATERIALS AND METHODS: The study was approved by the medical center Institutional Review Board, with waiver of informed consent. Forty-seven HCC nodules in 24 patients (18 men, six women; age range, 33-71 years; mean age, 56 years) were treated with single or double RF ablation sessions prior to liver transplantation. Histologic data from hematoxylin-eosin staining of explanted liver specimens were retrospectively reviewed to determine treatment success, which was defined as the absence of residual or recurrent viable carcinoma cells at treatment site. Tumor size and the presence of large (> or =3 mm) abutting vessels that were observed during imaging were tested as potential predictors of treatment success or failure (Fisher exact test). In patients who underwent postablation computed tomographic (CT) or magnetic resonance (MR) imaging within 3 months prior to transplantation (21 patients with 44 tumors), imaging results were analyzed for sensitivity and specificity of residual or recurrent tumor by using histologic data as the reference standard. RESULTS: Thirty-five (74%) of 47 ablated tumors, including 29 (83%) of 35 tumors less than 3 cm, were found to be successfully treated on the basis of histologic findings after a mean interval of 7.5 months between RF ablation and transplantation. Nodules that were successfully treated had mean maximal diameter of 2.0 cm, and nodules that were unsuccessfully treated had mean maximal diameter of 3.1 cm (P=.014). Seven (47%) of 15 perivascular lesions were successfully treated whereas 28 (88%) of 32 nonperivascular lesions were successfully treated (P <.01). Imaging correlation showed 100% (33 of 33) specificity and 36% (four of 11) sensitivity of postablation CT and MR imaging for the depiction of residual or recurrent tumor. CONCLUSION: Histologic evidence directly validates RF ablation as an effective treatment of small (<3 cm) HCC.     

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.     

Radiofrequency ablation with internally cooled versus perfused electrodes for the treatment of small hepatocellular carcinoma in patients with cirrhosis

PURPOSE: To compare the results of radiofrequency (RF) ablation with internally cooled electrodes (ICEs) versus perfused electrodes (PEs) in patients with cirrhosis with small (相似文献   

Early-stage hepatocellular carcinoma in patients with cirrhosis: long-term results of percutaneous image-guided radiofrequency ablation

PURPOSE: To perform a prospective, intention-to-treat clinical trial to determine the long-term survival rates of patients with hepatic cirrhosis and early-stage hepatocellular carcinoma (HCC) in whom percutaneous image-guided radiofrequency (RF) ablation was used as the sole first-line anticancer treatment. MATERIALS AND METHODS: The study was performed with approval of the ethics committee, and written informed consent was obtained for all patients. From June 1, 1996, to January 1, 2003, 206 patients (143 men, 63 women; age range, 51-81 years; mean age, 67 years +/- 7) who were excluded from surgery and who had Child class A or B cirrhosis with either a single HCC less than or equal to 5 cm in diameter or multiple (as many as three) HCCs less than or equal to 3 cm in diameter each were enrolled. RF ablation was performed in 187 (91%) of 206 patients; 19 (9%) were excluded from RF treatment because of unfavorable tumor location. Follow-up ranged from 3 to 78 months (mean, 24 months +/- 21) and included measurement of alpha-fetoprotein level, ultrasonography at 3-month intervals, and spiral computed tomography at 6-month intervals. Patients were observed for recurrence of the treated tumor and for the emergence of new HCC tumors. Survival probabilities were estimated with the Kaplan-Meier method, and differences between survival curves were evaluated with the log-rank test. RESULTS: At the end of the study, 145 patients were alive, and 61 were dead. In the intention-to-treat analysis, overall survival rates were 97% at 1 year, 67% at 3 years, and 41% at 5 years. Median survival was 49 months. In the 187 patients treated with RF ablation, overall survival rates were 97% at 1 year, 71% at 3 years, and 48% at 5 years. Median survival was 57 months. The difference between the two survival curves was not statistically significant (P=.5094). Survival of patients treated with RF ablation was dependent on Child class (P=.0006) and tumor multiplicity (P=.0133). Patients who had Child class A cirrhosis with solitary HCC (n=116) had 1-, 3-, and 5-year survival rates of 100%, 89% and 61%; median survival was 65 months. The 1-, 3-, and 5-year recurrence rates were 14%, 49%, and 81% for the emergence of new tumors and 4%, 10%, and 10% for local tumor progression. CONCLUSION: RF ablation is an effective first-line treatment for cirrhotic patients with early-stage HCC who were excluded from surgery.     

Repeat radiofrequency ablation for local progression of lung tumors: does it have a role in local tumor control?

PURPOSE: To retrospectively evaluate the role of repeat radiofrequency (RF) ablation for local progression of lung tumors in local tumor control. MATERIALS AND METHODS: From June 2001 to February 2007, the authors treated 797 lung tumors (primary lung cancer, n=66; metastatic lung neoplasm, n=731; mean tumor size, 1.7 cm) in 295 patients with RF ablation. After RF ablation, patients were followed-up with contrast-enhanced chest computed tomography at 1, 3, 6, 9, and 12 months and thereafter at 6-month intervals. Local progression was observed in 117 of the 797 lung tumors. Fifty repeat RF ablation sessions were performed for 56 tumors (primary lung cancer, n=9; metastatic lung neoplasm, n=47; mean tumor size, 2.7 cm) in 46 patients (33 men, 13 women; mean age, 59.6 years). Repeat RF ablation was not performed for the remaining 61 locally progressing tumors because it was not presumed to provide survival benefit. For all 797 tumors, the overall primary and secondary technique effectiveness rates (TERs) after the first RF ablation were compared with each other. To determine the risk factors for local control with repeat RF ablation, multiple variables were analyzed. Next, local control with repeat RF ablation was evaluated for tumors with and tumors without risk factors. RESULTS: The overall secondary TERs were significantly higher than the overall primary TERs (P<.00001). Tumor size of at least 2 cm at the first RF ablation (P=.045) and contact with bronchi (P=.045) or vessels (P=.048) were risk factors for local control with repeat RF ablation. The secondary TERs after the first RF ablation were 94% at 1 year, 68% at 2 years, and 55% at 3 years for tumors without risk factors and 60% at 1 year and 40% at 2 years for tumors with at least one risk factor. Among the 50 repeat RF ablation sessions, pneumothorax occurred in 13 sessions (26%), one of which necessitated chest tube placement; pleural effusion occurred in nine sessions (18%), all of which resolved spontaneously. Thermal injury of the brachial plexus occurred after one session. CONCLUSIONS: Repeat RF ablation improved the overall local control outcomes. In particular, it offered an opportunity to salvage tumors that had no risk factors but nevertheless progressed locally after the first RF ablation. Conversely, tumors with risk factors were not controlled sufficiently even after repeating the procedure.     

Small hepatocellular carcinoma: treatment with radio-frequency ablation versus ethanol injection

PURPOSE: To compare the effectiveness of radio-frequency (RF) ablation with that of percutaneous ethanol injection in the treatment of small hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Eighty-six patients with 112 small (< or = 3-cm-diameter) HCCs underwent RF ablation (42 patients with 52 tumors) or percutaneous ethanol injection (44 patients with 60 tumors). Therapeutic efficacy was evaluated with dual-phase spiral computed tomography performed at least 4 months after treatment. RESULTS: Complete necrosis was achieved in 47 of 52 tumors with RF ablation (90%) and in 48 of 60 tumors with percutaneous ethanol injection (80%). These results were obtained with an average of 1.2 sessions per tumor with RF ablation and 4.8 sessions per tumor with percutaneous ethanol injection. One major complication (hemothorax that required drainage) and four minor complications (intraperitoneal bleeding, hemobilia, pleural effusion, cholecystitis) occurred in patients treated with RF ablation; no complications occurred in patients treated with percutaneous ethanol injection. CONCLUSION: RF ablation results in a higher rate of complete necrosis and requires fewer treatment sessions than percutaneous ethanol injection. However, the complication rate is higher with RF ablation than with percutaneous ethanol injection. RF ablation is the treatment of choice for most patients with HCC.     

Radio-frequency ablation of hepatic metastases: postprocedural assessment with a US microbubble contrast agent--early experience.

PURPOSE: To evaluate contrast agent-enhanced ultrasonography (US) in the detection of untreated tumor after radio-frequency (RF) ablation of hepatic metastases. MATERIALS AND METHODS: Twenty patients with solitary colorectal liver metastases underwent percutaneous RF tumor ablation. Pre- and postablation imaging was performed with nonenhanced and enhanced color and power Doppler US and contrast-enhanced helical computed tomography (CT). Initial follow-up CT and US were performed 24 hours after ablation. The findings at US and CT were compared. RESULTS: Nonenhanced US demonstrated intratumoral signal in 15 of 20 metastases before ablation. This signal increased after contrast agent administration. Contrast-enhanced US performed 24 hours after ablation demonstrated residual foci of enhancement in three tumors, whereas no US signals were seen in any tumor on nonenhanced scans. CT demonstrated small (< 3-mm) persistent foci of residual enhancement in these three tumors and in three additional lesions that were not seen at US (US sensitivity, 50%; specificity, 100%; diagnostic agreement with CT, 85%). All six patients with evidence of residual tumor underwent repeat RF ablation. CONCLUSION: Contrast-enhanced US may depict residual tumor after RF application and thereby enable additional directed therapy. The potential reduction in treatment sessions and/or ancillary imaging procedures might increase the ease and practicality of percutaneous ablation of focal hepatic metastases.     

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.     

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     

Small hepatocellular carcinoma in cirrhosis: randomized comparison of radio-frequency thermal ablation versus percutaneous ethanol injection

PURPOSE: To compare the effectiveness of radio-frequency (RF) thermal ablation with that of percutaneous ethanol injection (PEI) for the treatment of small hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: A series of 102 patients with hepatic cirrhosis and either single HCC 5 cm in diameter or smaller or as many as three HCCs each 3 cm or smaller (overall number of lesions, 142) randomly received either RF ablation (n = 52) or PEI (n = 50) as the sole first-line anticancer treatment. Mean follow-up was 22.9 months +/- 9.4 (SD) in the RF group and 22.4 months +/- 8.6 in the PEI group. Prognostic value of treatment techniques was assessed with univariate and multivariate Cox proportional hazards regression models. RESULTS: One- and 2-year survival rates were 100% and 98% in the RF group and 96% and 88% in the PEI group, respectively (univariate relative risk [RR] = 0.20; 95% CI: 0.02, 1.69; P =.138). One- and 2-year local recurrence-free survival rates were 98% and 96% in the RF group and 83% and 62% in the PEI group, respectively (univariate RR = 0.17; 95% CI: 0.06, 0.51; P =.002). One- and 2-year event-free survival rates were 86% and 64% for the RF group and 77% and 43% for the PEI group, respectively (univariate RR = 0.48; 95% CI: 0.27, 0.85; P =.012). RF treatment was confirmed as an independent prognostic factor for local recurrence-free survival rates with multivariate analysis (adjusted RR = 0.20; 95% CI: 0.05, 0.73; P =.015). CONCLUSION: RF ablation is superior to PEI with respect to local recurrence-free survival rates.     

Combined radiofrequency ablation and adjuvant liposomal chemotherapy: effect of chemotherapeutic agent, nanoparticle size, and circulation time

PURPOSE: To evaluate the effects of liposomal chemotherapeutic agent, nanoparticle size, and liposome circulation time on tissue coagulation and intratumoral drug uptake when radiofrequency (RF) ablation is combined with adjuvant intravenous liposomal chemotherapy in an animal breast tumor model. MATERIALS AND METHODS: Ninety-one R3230 mammary adenocarcinoma nodules were implanted in 48 Fischer rats. First, standardized RF ablation was combined with intravenous liposomal doxorubicin, cisplatin, or 5-fluorouracil (35 tumors each). Second, three different-sized doxorubicin-containing nanoparticle preparations were combined with standardized RF ablation. Last, two doxorubicin-containing liposome preparations with different blood elimination half-lives were combined with RF ablation. Coagulation diameter and interstitial doxorubicin concentration were measured 48 hours after treatment and compared with use of statistical analysis. RESULTS: All combinations of RF with liposomal chemotherapy caused significantly greater tumor necrosis than RF alone (P<.05). Significantly increased necrosis was observed with intravenous liposomal RF/doxorubicin and RF/cisplatin compared with intravenous liposomal RF/5-fluorouracil (P<.01). Greater coagulation was observed with RF combined with 100-nm nanoparticles compared with 20-nm or 250-nm nanoparticles (P=.01 and P=.04, respectively). Additionally, greater intratumoral doxorubicin uptake was observed in the group treated with 20-nm nanoparticles compared with those treated with other sizes of nanoparticles (P<.05). RF plus liposomal doxorubicin produced greater coagulation and intratumoral doxorubicin uptake than RF plus 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid (P<.05). CONCLUSION: When combined with RF ablation, modification of adjuvant intravenous liposomal chemotherapy, including nanoparticle size, circulation time, and chemotherapeutic agent, can influence intratumoral drug accumulation and tissue coagulation.     

Hepatocellular carcinoma treated with radio-frequency ablation: spectrum of imaging findings.

Contrast material-enhanced Doppler or gray-scale harmonic ultrasonography (US) may help determine the completeness or long-term therapeutic efficacy of radio-frequency (RF) ablation of hepatocellular carcinoma (HCC). Successfully treated HCC is devoid of vascularity at color or power Doppler US. When the tumor is not completely treated, residual viable tumor can be detected. These contrast-enhanced US techniques may also help identify residual tumor when performed during repeat RF ablation, when accurate localization of viable tumor is needed. To date, contrast-enhanced computed tomography (CT) has been the most widely used imaging modality in the evaluation of therapeutic response after RF ablation of HCC. At follow-up CT, successfully ablated lesions appear as low-attenuation areas with no foci of contrast enhancement either within or at the periphery of the treated lesion, whereas any foci of enhancement indicate residual or recurrent tumor. Reactive hyperemia in tissue surrounding the ablated lesion, iatrogenic arterioportal shunting, and small intralesional air pockets are frequently seen at immediate follow-up CT. Gadolinium-enhanced dynamic magnetic resonance imaging is also useful in assessing therapeutic response following RF ablation of HCC, particularly when CT findings are inconclusive. Familiarity with these imaging findings is helpful in this setting. Copyright RSNA, 2003.     

Hepatocellular carcinoma treated with radio frequency ablation: an early evaluation with magnetic resonance imaging

PURPOSE: To determine the usefulness of nonenhanced T1-weighted spoiled gradient-recalled acquisition in the steady-state (SPGR) MRI in the early assessment of the efficacy of radio frequency (RF) therapy for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 23 patients with 28 HCC nodules treated with percutaneous RF ablation underwent nonenhanced MRI within two days after the RF procedure and contrast-enhanced computed tomography (CT) one week after. MR assessment of ablation efficacy according to the concentric zonal pattern on T1-weighted SPGR imaging was compared with the one-week CT and presence of local recurrence by means of follow-up study for 12 months or more. RESULTS: In 18 of 28 ablated nodules, SPGR images revealed a central hyperintense zone covering the entire tumor, CT showed a nonenhanced area covering the entire tumor, and no local recurrence was demonstrated in the follow-up studies. In nine of 28 nodules, the central hyperintense zone did not cover the entire tumor; and local recurrence was demonstrated in three nodules. In the remaining one nodule, no signal change was seen in the treated area on SPGR images and CT showed the presence of residual viable tumor. CONCLUSION: Nonenhanced T1-weighted MRI was considered useful for early assessment of the efficacy of RF therapy for HCC.     

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.     

Adrenal neoplasms: CT-guided radiofrequency ablation--preliminary results

PURPOSE: To evaluate initial experience with radiofrequency (RF) ablation of adrenal neoplasms. MATERIALS AND METHODS: Thirteen adrenal masses in 12 patients (bilateral metastases in one patient) were treated with computed tomography (CT)-guided percutaneous RF ablation. Eleven adrenal lesions were metastases (five from lung cancer, four from renal cell carcinoma, and two from melanoma); one lesion was a pheochromocytoma and one was an aldosteronoma. There were 10 men and two women (average age, 58 years; range, 40-77 years) in the study; average adrenal mass diameter was 3.9 cm (range, 1-8 cm). Average number of RF applications per adrenal mass was 2.7 (range, 1-5 applications); average time per application was 7.8 minutes (range, 4-13 minutes). An internally cooled single electrode was used in five sessions; an internally cooled cluster electrode was used in eight sessions. RESULTS: Average follow-up was 11.2 months (range, 1-46 months). Eleven of 13 lesions were treated successfully with RF ablation after one session. Successful treatment was defined as lack of enhancement of the treated region on follow-up CT images and resolution of the biochemical abnormality in two patients. In two patients with large adrenal lesions (4 and 8 cm in diameter), enhancement of residual tissue was observed after one treatment session; this finding was indicative of residual tumor. One patient with thrombocytopenia that resulted from chemotherapy had a small hematoma, but no transfusion was required. No patient developed hypertension during the RF application. No patient with metastases had recurrent tumor at the treated site, and this lack of recurrence indicated effective local control; 11 patients had progression of metastatic disease at extraadrenal sites. CONCLUSION: Preliminary data suggest that CT-guided RF ablation is an effective technique for local control of adrenal neoplasms.     

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.     

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.     

Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours/=4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours/=4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up.     

Contrast-enhanced harmonic ultrasound imaging in ablation therapy for primary hepatocellular carcinoma

The success rate of percutaneous radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) depends on correct targeting via an imaging technique. However, RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound (US), color Doppler, and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue. Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver. Two breakthroughs in the field of US technology, harmonic imaging and the development of second-generation contrast agents, have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions. Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor. Therefore, contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.     

Treatment of small HCC through radiofrequency ablation and laser ablation. Comparison of techniques and long-term results

PURPOSE: The aim of this trial was to compare the results obtained using laser ablation (LA) and radiofrequency ablation (RFA) to treat small hepatocellular carcinomas (HCC). MATERIALS AND METHODS: From 2003 to 2005, a total of 81 cirrhotic patients (59 Child-Pugh A, 22 Child-Pugh B) presenting a total of 95 HCC nodules (mean diameter 27.9 mm) were treated with LA (41) and RFA (40). RESULTS: Computed tomography (CT) revealed complete tumour ablation in 78% of nodules treated with LA and in 94% of those treated with RA; the disease-free interval was 16.50+/-8.1 months. The cumulative survival rates were 91.8%, 59% and 28.4% at 12, 36 and 60 months, respectively. The patients treated with RFA had better survival rates than those treated with LA, although this difference was not statistically significant (p=0.3299). Univariate analysis of survival revealed statistically significant differences between the Child-Pugh A and B groups (p<0.0001), between HCC nodules measuring < or =25 mm and >25 mm (p=0.0001) and between patients with a single nodule and with two nodules (p=0.0484). CONCLUSIONS: We found LA and RFA to be equally effective. However, RA appears more suited to patients with small HCC nodules and in Child-Pugh class A.