Percutaneous radiofrequency ablation of liver metastases in potential candidates for resection: the "test-of-time approach"

The management of solitary colorectal liver metastases

Surgical resection of solitary colorectal liver metastases is associated with long-term survival. Radiofrequency ablation used as the primary treatment option of solitary resectable colorectal liver metastases is associated with an increased risk of local recurrence that generally leads to worse survival compared to resection. In contrast with treatment of other hepatic malignancies, radiofrequency ablation is not equivalent to resection for colorectal liver metastases and should not be used as an alternative but limited to inoperable patients. Although overall survival rate after resection can be up to 71% at 5 years, the majority of patients develop recurrence. Preoperative chemotherapy contributes to decrease the risk of recurrence after resection of colorectal liver metastases. In patients with advanced solitary colorectal liver metastasis initially non suitable for resection, chemotherapy and portal vein embolization contribute to increase the number of surgical candidates whereas radiofrequency is rarely an option.

Microwave thermal ablation for hepatocarcinoma: six liver transplantation cases

Surgical resection for malignant hepatic tumors, especially hepatocarcinoma (HCC), has been demonstrated to increase overall survival; however, the majority of patients are not suitable for resection. Radiofrequency ablation (RFA) is the most widely used modality for radical treatment of small HCC (<3 cm). It improves 5-year survival compared with standard chemotherapy and chemical ablation, allowing down-staging of unresectable hepatic masses. Microwave ablation (MWA) has been extensively applied in Asia and was recently introduced in the United States of America and Europe with excellent results, especially with regard to large unresectable HCC. Our single-center experience between May 2009 and October 2010 included application of MWA to 154 patients of median age ± standard deviation of 63.5 ± 8.5 years, 6 males, and 1 female, of mean Model for End-Stage Liver Disease (MELD) score (10.1 ± 3.8). The HCC included, hepatitis C virus (HCV)-related (n=70; 45.5%); alcool (ETOH)-related (n=42; 27%), hepatitis B virus (HBV)-related (n=16; 10.5%); and cryptogenic cases (n=26; 17%). The cases were performed for radical treatment down-staging for multifocal pathology or bridging liver transplantation to orthotopic (OLT) in selected patients with single nodules. A computed tomography (CT) scan was performed at 1 month after the surgical procedure to evalue responses to treatment. Among 6 selected patients who underwent OLT; 5 (83.3%) showed disease-free survival at one-year follow-up. The radical treatment achieved no intraoperative evidence of tumor spread or of pathological signs of active HCC among the explanted liver specimens. In conclusion, a MWA seemed to be a safe novel approach to treat HCC and could serve as a "bridge" to OLT and down-staging for patients with HCC.

Radiofrequency ablation vs hepatic resection for solitary colorectal liver metastasis: A meta-analysis

AIM: To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).

METHODS: A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.

RESULTS: Seven nonrandomized controlled trials studies were included in this analysis. These studies included a total of 847 patients: 273 treated with RFA and 574 treated with HR. The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR: 0.41, 95% CI: 0.22-0.90, P = 0.008). RFA had a higher rate of local intrahepatic recurrence compared to HR (OR: 4.89, 95% CI: 1.73-13.87, P = 0.003). No differences were found between the two groups with respect to postoperative morbidity and mortality.

CONCLUSION: HR was superior to RFA in the treatment of patients with solitary CLM. However, the findings have to be carefully interpreted due to the lower level of evidence.

Percutaneous radiofrequency ablation using internally cooled wet electrodes for treatment of colorectal liver metastases

AIM

To evaluate the efficacy and safety of internally cooled wet (ICW) electrodes, which provide interstitial infusion of saline and intra-electrode cooling simultaneously, in the percutaneous radiofrequency ablation (RFA) of liver metastases from colorectal cancer.

MATERIALS AND METHODS

From February 2008 to October 2010, 27 patients with 35 hepatic metastatic lesions (mean size 1.99cm; range 0.7-3.8cm) underwent RFA using ICW electrodes. Of these 35 tumours, 32 had diameters ≤3cm, and three had diameters of 3-4cm. Moreover, 18 tumours were non-subcapsular and 17 were subcapsular.

RESULTS

No patients (0%) had major complications after RFA. During follow-up (median 27 months; range 4.5-36 months), 14 of the 35 treated lesions (40%) showed local tumour progression. The local tumour progression-free survival rates at 1 and 3 years were 73 and 56%, respectively. The local tumour progression-free survival period was significantly longer in patients with tumours ≤2cm than >2cm (p<0.001), but did not differ significantly between patients with non-subcapsular and subcapsular tumours (p=0.454). The overall 1 and 3 year survival rates after RFA were 100 and 77%, respectively.

CONCLUSIONS

Percutaneous RFA using ICW electrodes is safe and technically feasible for the treatment of liver metastases from colorectal cancer. It provides effective local tumour control with low complication rates and reduced number of needle placements.

Stereotactic body radiotherapy for colorectal liver metastases: a pooled analysis

BACKGROUND

This study was undertaken to determine outcomes of stereotactic body radiotherapy for colorectal liver metastases in a pooled patient cohort.

METHODS

Patients with colorectal liver metastases from 3 institutions were included if they had 1 to 4 lesions, received 1 to 6 fractions of stereotactic body radiotherapy, and had radiologic imaging ≥ 3 months post-treatment. Sixty-five patients with 102 lesions treated from August 2003 to May 2009 were retrospectively analyzed. A tumor control probability (TCP) model was used to estimate the 3-fraction dose required for > 90% local control after converting the schedule into biologically equivalent dose (BED), single-fraction equivalent dose, or linear quadratic model-based single-fraction dose.

RESULTS

Forty-seven (72%) patients had ≥ 1 chemotherapy regimen before stereotactic body radiotherapy, and 27 (42%) patients had ≥ 2 regimens. The median follow-up was 1.2 years (range, 0.3-5.2 years). The median dose was 42 gray (Gy; range, 22-60 Gy). When evaluated separately by multivariate analysis, total dose (P = .0015), dose/fraction (P = .003), and BED (P = .004) all correlated with local control by lesion. On multivariate analysis, nonactive extrahepatic disease was associated with overall survival (OS; P = .046), and sustained local control was closely correlated (P = .06). By using single-fraction equivalent dose, BED, or linear quadratic model-based single-fraction dose in the TCP model, the estimated dose range needed for 1-year local control > 90% is 46 to 52 Gy in 3 fractions.

CONCLUSIONS

Liver stereotactic body radiotherapy is well tolerated and effective for colorectal liver metastases. The strong correlation between local control and OS supports controlling hepatic disease even for heavily pretreated patients. For a 3-fraction regimen of stereotactic body radiotherapy, a prescription dose of ≥ 48 Gy should be considered, if normal tissue constraints allow.

Radiofrequency ablation as a treatment strategy for liver metastases from breast cancer

The American Cancer Society estimates that in 2007, 178,000 women in the United States will be diagnosed, and that 40,000 women will die from breast cancer. Metastatic breast cancer is a systemic disease, uncommonly involving an isolated organ. Liver metastases from breast cancer occur in ~50% of the patients who develop breast cancer metastases and are associated with a poor outcome. Hepatic metastasectomy as an adjuvant treatment even in patients with stable extrahepatic disease has been shown to impart a significant survival advantage over chemotherapy alone. In the treatment of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM), radiofrequency ablation (RFA) has been shown to be a safe, minimally invasive treatment option with low morbidity and short hospital stay that is more readily repeatable than resection. The data supporting RFA of breast cancer liver metastases (BCLM) is currently limited to small, retrospective series that, like hepatic resection, have demonstrated adjuvant RFA improves survival compared with chemotherapy alone. This review will examine the rationale, indications, supportive data, and complications of RFA in the treatment of BCLM.

Percutaneous radiofrequency thermal ablation of primary and metastatic hepatic tumors: current concepts and review of the literature

The liver is a common site for primary malignancy and hematogenous metastasis. Although surgical resection of primary or metastatic hepatic tumors is generally regarded as first-line therapy, the majority of patients with hepatic malignancy have disease that is not amenable to surgical resection because of tumor location, poor hepatic reserve, or medical comorbidities. This has led to significant interest in the development of nonsurgical image-guided therapies, including radiofrequency ablation (RFA). RFA is appealing as a minimally invasive therapy that may be performed on an outpatient basis. It enables ablation of an area 3 to 5 cm in diameter, with relatively low morbidity and mortality rates. The results concerning the use of percutaneous RFA in the treatment of hepatocellular carcinoma, colorectal metastases, and other hepatic metastases are reviewed in this article. Clinical and technical considerations and complications are also discussed.

Stereotactic radiofrequency ablation (SRFA) of liver lesions: technique effectiveness, safety, and interoperator performance

PURPOSE

To evaluate technique effectiveness, safety, and interoperator performance of stereotactic radiofrequency ablation (SRFA) of liver lesions.

METHODS

Retrospective review including 90 consecutive patients from January 2008 to January 2010 with 106 computed tomography-guided SRFA sessions using both single and multiple electrodes for the treatment of 177 lesions: 72 hepatocellular carcinoma (HCC) and 105 metastases with a mean size of 2.9 cm (range 0.5-11 cm). Technique effectiveness and 1-year local recurrence were evaluated by computed tomographic scans. Complications, mortality, and hospital days were recorded. The performance between an experienced and inexperienced interventional radiologist was compared.

RESULTS

The overall technique effectiveness after a single SRFA was 95.5% (93.1% for HCC and 97.1% for metastases). Four of the eight unsuccessfully treated lesions could be retreated (secondary technique effectiveness of 97.7%). Local recurrence at 1 year was 2.9%. Technique effectiveness was significantly different for lesions<5 cm (96.7%) and >5 cm (87.5%) (P=0.044) but not for lesions<3 cm (95.9%) and 3-5 cm (100%). Compared to clear parenchymal property (97.3%), vessel vicinity (93.3%) (P=0.349) and subcapsular (95.2%) (P=0.532) had no, but hollow viscera vicinity (83.3%) had a significantly lower technique effectiveness (P=0.020). Mortality rate was 0.9%. Major complications and hospital days were higher for cirrhosis Child-Pugh B (20%, 7.2 days) than Child-Pugh A (3.1%, 4.7 days) patients and for metastases (5.1%, 4.3 days). There was no significant difference in interoperator performance.

CONCLUSION

SRFA allowed for efficient, reliable, and safe ablation of large-volume liver disease.

É possível diminuir o sangramento em hepatectomias sem a realização de exclusão vascular total ou parcial?: Resultados do uso de radiofrequência bipolar com agulhas resfriadas

RACIONAL: Embora a ressecção seja ainda o procedimento de escolha no tratamento curativo das lesões malignas do fígado, o sangramento permanece como fator de morbidade com grande impacto na cirurgia hepática. Com o intuito de minimizar esta complicação, diversas opções tecnológicas têm sido utilizadas, entre elas mais recentemente a radiofrequência, permitindo que o procedimento seja realizado com incisões menores, sem necessidade de clampeamento vascular, com mínima dissecção hepática, ou sangramento. OBJETIVO: Apresentar os resultados em uma série de pacientes utilizando nova técnica de ressecção do parênquima hepático através de agulhas paralelas de radiofrequência bipolar desenvolvidas pelos próprios autores, verificando o impacto no sangramento trans-operatório dos pacientes submetidos à hepatectomias. MÉTODOS: Sessenta pacientes foram submetidos à ressecção hepática através do uso da radiofrequência bipolar. O sangramento per-operatório foi avaliado através da medição do volume coletado em aspirador e pela diferença de peso nas compressas utilizadas durante o procedimento. Todos os casos foram acompanhados em sua função hepatocitária através de exames laboratoriais durante a primeira semana de pós-operatório. RESULTADOS: As ressecções hepáticas foram realizadas com média de 87 minutos, tamanho médio da incisão abdominal de 14 cm e sangramento médio de 58 mililitros. Nenhum paciente recebeu transfusão de sangue ou derivados. Não foram utilizados cateteres venosos centrais. Todos pacientes obtiveram rápida recuperação anestésica, obtendo alta da sala de recuperação para a enfermaria em menos de 12 horas. A drenagem pós-operatória foi anotada até a retirada do dreno abdominal em todos os pacientes. O tempo de internação hospitalar médio foi de 3,2 dias. Após um pico de elevação das provas de função hepática nos primeiros três dias, todos apresentaram retorno destes exames aos parâmetros pré-operatórios ao final do 1o mês. CONCLUSÃO: É possível, factível e válida a utilização de agulhas de radiofrequência para a realização de hepatectomias, mesmo maiores, reduzindo o sangramento.

Viable tumor tissue adherent to needle applicators after local ablation: a risk factor for local tumor progression

Background

Local tumor progression (LTP) is a serious complication after local ablation of malignant liver tumors, negatively influencing patient survival. LTP may be the result of incomplete ablation of the treated tumor. In this study, we determined whether viable tumor cells attached to the needle applicator after ablation was associated with LTP and disease-free survival.

Methods

In this prospective study, tissue was collected of 96 consecutive patients who underwent local liver ablations for 130 liver malignancies. Cells and tissue attached to the needle applicators were analyzed for viability using glucose-6-phosphate-dehydrogenase staining and autofluorescence intensity levels of H&E stained sections. Patients were followed-up until disease progression.

Results

Viable tumor cells were found on the needle applicators after local ablation in 26.7% of patients. The type of needle applicator used, an open approach, and the omission of track ablation were significantly correlated with viable tumor tissue adherent to the needle applicator. The presence of viable cells was an independent predictor of LTP. The attachment of viable cells to the needle applicators was associated with a shorter time to LTP.

Conclusions

Viable tumor cells adherent to the needle applicators were found after ablation of 26.7% of patients. An independent risk factor for viable cells adherent to the needle applicators is the omission of track ablation. We recommend using only RFA devices that have track ablation functionality. Adherence of viable tumor cells to the needle applicator after local ablation was an independent risk factor for LTP.

CT-guided radiofrequency ablation as a salvage treatment of colorectal cancer hepatic metastases developing after hepatectomy

PURPOSE

To evaluate the clinical outcomes of percutaneous radiofrequency (RF) ablation of colorectal cancer liver metastases (CLMs) that recur after hepatectomy.

MATERIALS AND METHODS

From December 2002 to December 2008, 71 CLMs that developed after hepatectomy were ablated in 56 patients. Medical records and imaging were reviewed to determine technique effectiveness/complete ablation (ie, ablation defect covering the entire tumor on 4-6-week postablation computed tomography [CT]), complications, and local tumor progression (LTP) at the site of ablation. LTP-free and overall survival were calculated by using Kaplan-Meier methodology. A modified clinical risk score (CRS) including nodal status of the primary tumor, time interval between diagnoses of the primary tumor and liver metastases, number of tumors, and size of the largest tumor was assessed for its effect on overall survival and LTP.

RESULTS

Tumor size ranged between 0.5 and 5.7 cm. Complete ablation was documented in 67 of 71 cases (94%). Complications included liver abscess (n = 1) and pleural effusion (n = 1). Median overall survival time was 31 months. One-, 2- and 3-year overall survival rates were 91%, 66%, and 41%, respectively. CRS was an independent factor for overall survival (74% for CRS of 0-2 vs 42% for CRS of 3-4 at 2 y; P = .03) and for LTP-free survival (66% for CRS of 0-2 vs 22% for CRS of 3-4 at 1 y after a single ablation; P <.01).

CONCLUSIONS

CT-guided RF ablation can be used to treat recurrent CLM after hepatectomy. A low CRS is associated with better clinical outcomes.

Ablation of pulmonary malignancy: current status

Since the first reported use of radiofrequency ablation of the lung in 2000, the field of image-guided lung ablation has received a considerable amount of attention. Survival studies have demonstrated the potential utility of thermal ablation in the treatment of patients with early-stage primary and limited secondary pulmonary tumors with promising results. Diagnostic imaging studies have advanced the understanding of the expected immediate postablation appearance of treated lesions, leading the way for early detection of local tumor progression. These survival studies and the expected imaging follow-up of these patients are reviewed herein.

Imaging to optimize liver tumor ablation

Surgical resection remains the ideal treatment for hepatocellular carcinoma and metastasis to the liver. Many alternatives are available for treatment of nonsurgical candidates. Regardless of treatment, optimizing imaging in the pretreatment, treatment and post-treatment settings is critical in order to lower the rates of local tumor progression and maximize the effectiveness of treatment that may result in prolonged survival. This article summarizes some basic imaging techniques of primary and metastatic liver tumors with a focus on how to optimize their treatment with ablation.

Thermoablation of colorectal liver metastasis

Thermoablation is a local therapy that is effective in in situ destruction of colorectal liver metastasis while preserving surrounding normal liver tissue. It is less invasive compared to surgery, easy to use, and can be repeated. The therapy provides local control of unresectable disease and is an alternative therapy for small resectable lesions in patients with insufficient hepatic reserve after resection or coexistent comorbid conditions. It can artificially increase the resection margin thus increasing the number of patient candidate for resection. When used in conjunction with liver resection it clears the liver of multiple lesions that are surgically inaccessible or unresectable. Main limitations of the treatment are local recurrence of the disease, treatment-related complications, and questionable impact on patient. Outcome of therapy can be improved when used as part of multimodality treatment.

Advanced hepatic ablation technique for creating complete cell death: irreversible electroporation

PURPOSE

To evaluate the effectiveness of irreversible electroporation (IRE) in hepatic tissue ablation and the radiologic-pathologic correlation of IRE-induced cell death.

MATERIALS AND METHODS

On approval of the animal research committee, 16 Yorkshire pigs underwent ultrasonography (US)-guided IRE of normal liver. A total of 55 ablation zones were created, which were imaged with US, magnetic resonance (MR) imaging, and computed tomography (CT) and evaluated with immunohistochemical analysis, including hematoxylin-eosin (H-E), Von Kossa, and von Willibrand factor (vWF) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

RESULTS

At gross section examination, the mean diameter of the ablation zones was 33.5 mm + or - 3.0 (standard deviation) and was achieved in 6.9 minutes (mean total procedure time per ablation), with a mean difference of 2.5 mm + or - 3.6 between US and gross section measurements (r = 0.804). No complications were seen in any of the 16 animals. IRE ablation zones were well characterized with US, CT, and MR imaging, and real-time monitoring was feasible with US. H-E, Von Kossa, and vWF staining showed complete cell death, with a sharply demarcated treatment area. Bile ducts and vessels were completely preserved. Areas of complete cell death were stained positive for apoptotic markers (TUNEL, BCL-2 oncoprotein), suggesting involvement of the apoptotic process in the pathophysiology of cell death caused by IRE.

CONCLUSION

In an animal model, IRE proved to be a fast, safe, and potent ablative method, causing complete tissue death by means of apoptosis. Cell death is seen with full preservation of periablative zone structures, including blood vessels, bile ducts, and neighboring nonablated tissues.

Radiofrequency ablation as first-line treatment in patients with early colorectal liver metastases amenable to surgery

OBJECTIVE

Aiming at avoidance of futile surgery, we have tested whether radiofrequency ablation (RFA) may be used as first-line treatment in patients with colorectal metastases (CRLM) occurring within the first year after colorectal surgery.

SUMMARY BACKGROUND DATA

Surgical resection is the standard treatment in patients with CRLM. Major retrospective analyses have identified the interval between colorectal surgery and the occurrence of CRLM to be of prognostic importance. So far, it is unknown whether survival of the respective patients is hampered if RFA is used as first-line treatment.

METHODS

According to a clinical pathway, we have treated patients with CRLM detected within the first year after colorectal surgery preferentially by RFA (n=28). Resection (n=82) was performed in patients who were deemed not amenable to RFA due to number, size, or location of metastatic lesions. The diameter of lesions differed between the groups. All other characteristics of patients and lesions were comparable. Local recurrence and new hepatic lesions were treated with repeated RFA or surgery whenever possible.

RESULTS

Local recurrence at the site of ablation or resection occurred in 32% and 4% (P<0.001), new metastases apart from the site of previous treatment in 50% and 34% (P=0.179), and systemic recurrence in 32% and 37% (P=0.820) of the patients after RFA and surgery, respectively. Time to progression was significantly shorter in patients primarily treated with RFA (203 vs. 416 days; P=0.017). After primary treatment, 9 RFA patients and 8 surgery patients were amenable to repeated RFA or repeated surgery resulting in identical rates of disease-free patients and identical 3-year overall survival in both treatment groups: 67% and 60%, respectively; P=0.93.

CONCLUSIONS

Despite striking differences in local tumor recurrence and shorter time to progression, survival in patients with early CRLM does not depend on the mode of primary hepatic treatment.

Extension of hepatic necrosis secondary to current arcing to surgical clips: a potential complication of radiofrequency ablation

The authors present a case report of a 67-year-old woman who underwent radiofrequency ablation of recurrent hepatic metastases. She was managed 2 years previously with a right hemi-hepatectomy. Subsequent to RF ablation she developed hepatic necrosis extending in a linear fashion to two of the metallic surgical clips at the free edge of the liver, consistent with current arcing.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

PURPOSE

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM).

METHODS

The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library.

RESULTS

Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches.

CONCLUSION

There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Society of Interventional Radiology position statement on percutaneous radiofrequency ablation for the treatment of liver tumors

Focal tumor ablation--whether applied percutanously, laparoscopically, or by means of open surgery--is an effective therapy for selected liver tumors. The choice of liver ablation as well as the choice between percutaneous and surgical approaches is dependent on tumor factors, patient factors, and other viable treatment options. Currently, the largest cumulative reported experience is with radiofrequency (RF) ablation of hepatocellular carcinoma and colorectal metastases. This document is a position statement of the Interventional Oncology Task Force and the Standards Division of the Society of Interventional Radiology regarding the use of percutaneous RF ablation for the treatment of liver tumors.

Radiofrequency ablation of hepatic tumours: effect of post-ablation margin on local tumour progression

PURPOSE

The purpose of this study was to retrospectively evaluate the relationship between post-ablation margins and local tumour progression following radiofrequency ablation (RFA) of hepatocellular carcinomas and colorectal liver metastases.

METHODS

Eighty-three patients with 107 hepatic tumours who underwent RFA were divided into two groups: the hepatocellular carcinoma (HCC) group (55 patients with 69 lesions) and the colorectal liver metastases group (28 patients with 38 lesions). Post-ablation margins were calculated on 1-month follow-up contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) studies. Efficacy was evaluated at 1-month post-ablation, then at 3-month intervals for the first year and biannually thereafter.

RESULTS

The results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.020) and tumour size smaller than 2.5 cm (P = 0.001) significantly correlated with local control for the HCC group. In the colorectal liver metastases group, the results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.345) and tumour size smaller than 2.5 cm (P = 0.168) did not correlate with local control.

CONCLUSION

Percutaneous RFA is more effective in achieving local control in patients with HCCs than with colorectal liver metastases.

Radiofrequency ablation for metachronous hepatic metastases from gastric cancer

The objective of this study was to evaluate the results of radiofrequency ablation (RFA) for the treatment of metachronous hepatic metastases from gastric adenocarcinoma. Between January 2000 and February 2008, we retrospectively reviewed 7 cases for which RFA was performed for treating metachronous hepatic metastases after resection of the primary gastric adenocarcinoma. The median period between curative gastrectomy and metachronous hepatic metastasis was 14 months (range: 6 to 48 mo). The median survival of the patients was 11.0 months (range: 5.5 to 39.2) after the first detection of hepatic metastases and 10.0 months (range: 5 to 38.2) after the first RFA. Hepatic metastases recurred 3 to 21 months after RFA in all patients. A second RFA was performed for a single recurrent hepatic metastasis in 1 patient and this patient survived more than 3 years without recurrence until the time of this study. In conclusion, the efficacy of RFA alone for metachronous hepatic metastases from gastric adenocarcinoma was disappointing due to multiple intrahepatic recurrences. Combination therapy such as systemic chemotherapy or hepatic arterial infusion chemotherapy adjuvant to RFA would more reasonable for treating hepatic metastases from gastric cancer.

Breast cancer liver metastases: US-guided percutaneous radiofrequency ablation--intermediate and long-term survival rates

PURPOSE

To retrospectively assess the local control and intermediate- and long-term survival of patients with liver metastases from breast cancer who have undergone percutaneous ultrasonography (US)-guided radiofrequency (RF) ablation.

MATERIALS AND METHODS

This study was approved by the hospital ethics committee, and all patients provided written informed consent. RF ablation was used to treat 87 breast cancer liver metastases (mean diameter, 2.5 cm) in 52 female patients (median age, 55 years). Inclusion criteria were as follows: fewer than five tumors, maximum tumor diameter of 5 cm or smaller, and disease either confined to the liver or stable with medical therapy. Forty-five (90%) of 50 patients had previously undergone chemotherapy, hormonal therapy, or both, and had no response or an incomplete response to the treatment. Contrast material-enhanced computed tomography and US were performed to evaluate complications and technical success and to assess for local tumor progression during follow-up. The Kaplan-Meier method was used to assess survival, and results were compared between groups with a log-rank test. Cox regression analysis was used to assess independent prognostic factors that affected survival.

RESULTS

Complete tumor necrosis was achieved in 97% of tumors. Two (4%) minor complications occurred. Median time to follow-up from diagnosis of liver metastasis and from RF ablation was 37.2 and 19.1 months, respectively. Local tumor progression occurred in 25% of patients. New intrahepatic metastases developed in 53% of patients. From the time of first RF ablation, overall median survival time and 5-year survival rate were 29.9 months and 27%, respectively. From the time the first liver metastasis was diagnosed, overall median survival time was 42 months, and the 5-year survival rate was 32%. Patients with tumors 2.5 cm in diameter or larger had a worse prognosis (hazard ratio, 2.1) than did patients with tumors smaller than 2.5 cm in diameter.

CONCLUSION

Survival rates in selected patients with breast cancer liver metastases treated with RF ablation are comparable to those reported in the literature that were achieved with surgery or laser ablation.

Open surgical is superior to percutaneous access for radiofrequency ablation of hepatic metastases

PURPOSE

This study was designed to determine the best approach to radiofrequency ablation (RFA) in the liver.

METHODS

From a total of 41 procedures, 37 patients with 47 tumors were treated with RFA for metastatic disease. Indications included colorectal cancer (n=28, 68%), neuroendocrine tumors (n=2, 5%), gynecological primaries (n=4, 10%), pancreatic/duodenal cancer (n=2, 5%), and miscellaneous entities (n=5, 12%). Mean follow-up period was 18 (median, 18) months. All ways of approach to RFA were applied: percutaneous was chosen in 17 (41.5%), laparoscopic and hand-assisted laparoscopic in 5 (12.2%), and open surgical in 19 cases (46.3%), and in 10 cases, RFA was combined with hepatic resection. The average maximum tumor size was 2.3 (range, 0.8-6) cm, and the mean number of nodules treated per patient in a single session was 1.3 (range, 1-3).

RESULTS

Overall survival was 59.5% at 2 years, recurrence-free 2-year survival was 12.6%, local tumor recurrence rate was 34%, and overall recurrence was 75.6%. Local tumor recurrence and disease-free survival were significantly improved in the open surgically treated patients compared with the percutaneous treatment group (15.8% [n=3] vs. 58.8% [n=10] and 11.5 vs. 7.9 months, p<0.01 [chi2 test] and p<0.05 [log-rank test], respectively).

CONCLUSIONS

Open surgical approach is superior to percutaneous access for RFA in metastatic hepatic disease.

Radiofrequency ablation of primary and metastatic lung cancers

Radiofrequency ablation is an accepted method of therapy for unresectable liver cancer. Most recently, interest in using this technology for treatment of primary and metastatic lung tumors has increased. Early animal studies have led to numerous human trials that suggest that radiofrequency ablation can play a major role in treatment of both early-stage primary lung cancer and metastatic lesions. Technical aspects of this therapy as well as areas of further research are discussed.

Microwave coagulation therapy for hepatic tumors: review of the literature and critical analysis

BACKGROUND

Surgical resection of malignant hepatic tumors has been demonstrated to increase overall survival; however, the majority of patients are not candidates for resection. For patients with unresectable tumors, various chemical and thermal ablation modalities have been developed. microwave coagulation therapy (MCT) is one such thermal ablation modality and the purpose of this review is to evaluate the presently available data for MCT and assess the level of evidence to support its clinical use.

METHODS

This review is limited to published studies in the English literature including at least 30 patients per study with MCT for hepatocellular cancer (HCC) or colorectal hepatic metastasis (CRHM). Patterns of local recurrence, complications and survival outcome of MCT ablation are presented and discussed including assessment of Asian experience using the 2.4GHZ device and American experience using the 914MHZ device.

CONCLUSIONS

Although randomized controlled trials comparing RFA and MCT for hepatic ablation are lacking, our review (based on level 2 data) supports that MCT may be optimal when larger necrosis zones and/or ablation of multiple lesions are the objectives. The data support that the potential procedural advantage(s) noted for ablation of CRHM and HCC >3cm, is not supported for HCC <3cm; moreover MCT shares with all other ablation modalities a high rate of locoregional recurrence in HCC; likely due to the multicentricity of this disease process.

Radiofrequency ablation vs. resection for hepatic colorectal metastasis: therapeutically equivalent?

INTRODUCTION

The role of ablation for hepatic colorectal metastases (HCM) continues to evolve as ablation technology changes and systemic chemotherapy improves. Our aim was to evaluate the therapeutic efficacy of radiofrequency ablation (RFA) of HCM compared to surgical resection.

METHODS

A retrospective review of our 1,105 patient prospective hepatic database from August 1995 to July 2007 identified 192 patients with only hepatic resection or only ablation for HCM.

RESULTS

Patients who underwent RFA were similar to resection patients based on a similar Fong score (1.8 vs. 2.1 p = 0.28), presence of extrahepatic disease (15% vs. 9% p = 0.19), mean number of hepatic lesions (2.8 vs. 2.1 p = 0.14), and prior chemotherapy (67% vs. 60% p = 0.33). Median time to recurrence was shorter with ablation than resection (12.2 vs. 31.1 months; p < 0.001). Recurrence at the ablation-resection site was more common with ablation than resection occurring 17% vs. 2% (p < or = 0.001) of the time, respectively. Distant recurrence in the liver was also more common with ablation occurring in 33% of patients vs. 14% for resection (p = 0.002).

CONCLUSIONS

Surgical resection is associated with a lower chance of recurrence and a longer disease-free interval than RFA and should remain the treatment of choice in resectable HCM.

Treating hepatocellular carcinoma without liver transplantation

Hepatocellular carcinoma, a significant health problem throughout the world, generally occurs in the setting of cirrhosis. Choice of treatment depends on the size and location of the tumor and hepatic reserve. Liver transplantation provides the best chance for long-term survival and can be performed regardless of hepatic reserve, but it requires small tumor sizes and is available to only a few patients. All other treatments require adequate hepatic reserve. Surgical resection, percutaneous ethanol injection, and radiofrequency ablation are effective treatments for patients with good hepatic reserve and small tumors isolated to the liver. For larger and multinodular tumors, chemoembolization is the best choice. With metastasis, portal vein invasion, or large bilobar disease and intact hepatic function, modest improvements in survival have occurred with the use of sorafenib, a recently approved targeted chemotherapy agent. Patients with poor hepatic function or low performance status should receive only supportive care.

Pathomorphologic evaluation of pulmonary radiofrequency ablation: proof of cell death is characterized by DNA fragmentation and apoptotic bodies

BACKGROUND

Radiofrequency (RF) ablation is an increasingly applied technique. Promising results of hepatic RF ablation raised expectations of its capabilities for treatment of primary and secondary lung tumors. Because of different thermal and electrical properties of lung tissue, compared with liver tissue, a simple analogy of tissue response is not possible. The authors aimed to evaluate the effectiveness of image-guided pulmonary RF ablation and to characterize pathomorphology of tissue response.

METHODS

RF ablations of 11 pulmonary malignancies in 9 patients were performed under computed tomography (CT)-guidance. Three days after RF ablation, surgical resection was performed followed by pathologic examination. Specimens were evaluated macroscopically, histologically by hematoxylin and eosin (H & E) staining, terminal deoxy-nucleotidyl transferase-mediated nick end-labeling (TUNEL), and electron microscopy.

RESULTS

Tumor tissues and adjacent lung tissues were characterized by double-strand fragmentation as determined by TUNEL. Ultrastructurally apoptotic bodies were found, indicating apoptotic cells. Criteria for tissue necrosis were not fulfilled by standard histological staining (H & E), showing preserved tissue architecture and only few microscopic cellular details suggestive of tumor regression. Because of DNA fragmentation, as determined by TUNEL and results from electron microscopy, the authors confirmed the tumor tissue to be completely ablated in 10 (90.9%) cases. However, in 2 cases, a safety margin was absent.

CONCLUSIONS

CT-guided pulmonary RF ablation of pulmonary malignancies is a locally effective treatment. Three days after RF ablation, tumor tissue seemed to be thermally fixed still showing characteristics of vital tumor tissue in standard histological staining; however the tissue proved to be in regression toward coagulative necrosis verified ultrastructurally and by TUNEL.

Heated lipiodol as an embolization agent for transhepatic arterial embolization in VX2 rabbit liver cancer model

PURPOSE

To evaluate the therapeutic effect of heated (60 degrees C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer.

MATERIALS AND METHODS

Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 degrees C) (1mL), lipiodol (60 degrees C) (1mL) or control (physiological saline (37 degrees C) (1mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected before injection and at 4 and 7 days after injection, and the level of aspartate aminotransferase (AST) was checked. The survival period of the three groups of rabbits after treatment was also recorded. During the last course of their disease, the rabbits were given analgesics to relieve suffering.

RESULTS

The tumor growth rate in the lipiodol (60 degrees C) group (0.92+/-0.21, tumor volume from 1811+/-435 to 1670+/-564mm(3)) was significantly lower than that in the control group (3.48+/-1.17, tumor volume from 1808+/-756 to 5747+/-1341mm(3)) (P<0.05) and in the doxorubicin-lipiodol (37 degrees C) group (1.69+/-0.26, tumor volume from 1881+/-641 to 2428+/-752mm(3)) (P<0.05). Consequently, the survival period of the animals in the lipiodol (60 degrees C) group (41.0+/-3.0 days) was significantly greater than that in the doxorubicin-lipiodol (37 degrees C) group (38.0+/-2.5 days) (P<0.05). On the other hand, there was no statistically significant difference in serum AST levels between the lipiodol (60 degrees C) group (148.2+/-11.3UL(-1)) and the doxorubicin-lipiodol (37 degrees C) group (139.7+/-12.3UL(-1)) (P>0.05). However, the serum AST level in the lipiodol (60 degrees C) group was significantly higher at 4 days after injection (P<0.05) than in the control group (68.6+/-6.6UL(-1)).

CONCLUSIONS

Treatment with lipiodol (60 degrees C) resulted in an effect on serum AST levels similar to that caused by treatment with doxorubicin-lipiodol (37 degrees C). Thus, lipiodol (60 degrees C) treatment could greatly prolong the survival period of rabbits with VX2 cancer by inhibiting tumor growth.

Detection of liver metastases: Gadoxetic acid-enhanced three-dimensional MR imaging versus ferucarbotran-enhanced MR imaging

PURPOSE

To compare the diagnostic performance of gadoxetic acid-enhanced MRI with ferucarbotran-enhanced MRI for the detection of liver metastases.

MATERIALS AND METHODS

Thirty-six patients with 80 liver metastases who underwent gadoxetic acid-enhanced MRI using a three-dimensional volumetric interpolated technique and ferucarbotran-enhanced MRI with a mean interval of 7 days (range, 5-10 days) were included in this study. Two observers independently interpreted the two sets of images - the gadoxetic acid set (unenhanced, early dynamic and 20min delayed phase images) and the ferucarbotran set (unenhanced and ferucarbotran-enhanced T2*-weighted-gradient echo and T2-weighted turbo spin echo images). Diagnostic accuracy was evaluated using the alternative-free response receiver operator characteristic (ROC) method. Sensitivity and positive predictive value were also evaluated.

RESULTS

There was a trend toward increased areas under the ROC curve (Az values) for the gadoxetic acid set (0.950, 0.948) as compared with the ferucarbotran set (0.941 and 0.939) of images, but no significant difference was found for both observers (p<0.05). Sensitivities of the gadoxetic acid set (93.8% and 92.5%) were also slightly better than those of the ferucarbotran set (88.8% and 87.5%) with no significant difference (p=0.13). The two image sets showed similar positive predictive values (98.7% and 98.6%, respectively).

CONCLUSIONS

Gadoxetic acid-enhanced MRI showed comparable diagnostic performance to ferucarbotran-enhanced MRI for the detection of liver metastases.

Resection versus laparoscopic radiofrequency thermal ablation of solitary colorectal liver metastasis

PURPOSE

There is scant data in the literature regarding radiofrequency thermal ablation (RFA) versus resection of colorectal liver metastases. The aim of this study is to compare the clinical profile and survival of patients with solitary colorectal liver metastasis undergoing resection versus laparoscopic RFA.

METHODS

Between 1996 and 2007, 158 patients underwent RFA (n = 68) and open liver resection (n = 90) of solitary liver metastasis from colorectal cancer. Patients were evaluated in a multidisciplinary fashion and allocated to a treatment type. Data were collected prospectively for the RFA patients and retrospectively for the resection patients.

RESULTS

Although the groups were matched for age, gender, chemotherapy exposure and tumor size, RFA patients tended to have a higher ASA score and presence of extra-hepatic disease (EHD) at the time of treatment. The main indication for referral to RFA included technical reasons (n = 25), patient comorbidities (n = 24), extra-hepatic disease (n = 10) and patient decision (n = 9). There were no peri-operative mortalities in either group. The complication rate was 2.9% (n = 2) for RFA and 31.1% (n = 28) for resection. The overall Kaplan-Meier median actuarial survival from the date of surgery was 24 months for RFA patients with EHD, 34 months for RFA patients without EHD and 57 months for resection patients (p < 0.0001). The 5-year actual survival was 30% for RFA patients and 40% for resection patients (p = 0.35).

CONCLUSIONS

This study shows that, although patients in both groups had a solitary liver metastasis, other factors including medical comorbidities, technically challenging tumor locations and extra-hepatic disease were different, prompting selection of therapy. With a simultaneous ablation program, higher risk patients have been channeled to RFA, leaving a highly selected group of patients for resection with a very favorable survival. RFA still achieved long-term survival in patients who were otherwise not candidates for resection.

[Metastases of colorectal carcinoma]

Metastases of colorectal cancer represent an interdisciplinary therapeutic challenge. Evidence-based guidelines are supportive of treatment decisions in specific situations with the objective to improve the therapeutic outcome for patients. Interventional tumor therapies are increasingly applied therapeutic options in the treatment of colorectal metastases. The current literature indicates that thermoablation of colorectal liver metastasis can lead to an improved survival in selected patients. However, recommendation of thermoablation as a part of guidelines for the therapy of colorectal metastases is restricted due to a shortcoming of randomized controlled trials. Therefore, interventional tumor therapies have to be evaluated in comparison with standard therapies, particularly with regard to surgical resection and chemotherapy. Moreover, the interdisciplinary combination of tumor ablation, surgical resection, and chemotherapy is a promising approach for the optimization of oncological therapy strategies in the treatment of colorectal metastases.

Society of Interventional Radiology position statement on percutaneous radiofrequency ablation for the treatment of liver tumors

Focal tumor ablation--whether applied percutanously, laparoscopically, or by means of open surgery-is an effective therapy for selected liver tumors. The choice of liver ablation as well as the choice between percutaneous and surgical approaches is dependent on tumor factors, patient factors, and other viable treatment options. Currently, the largest cumulative reported experience is with radiofrequency (RF) ablation of hepatocellular carcinoma and colorectal metastases. This document is a position statement of the Interventional Oncology Task Force and the Standards Division of the Society of Interventional Radiology regarding the use of percutaneous RF ablation for the treatment of liver tumors.

Comparative study of resection and radiofrequency ablation in the treatment of solitary colorectal liver metastases

BACKGROUND

We compared outcomes in patients with solitary colorectal liver metastases treated by either hepatic resection (HR) or radiofrequency ablation (RFA).

METHODS

A retrospective analysis from a prospective database was performed on 67 consecutive patients with solitary colorectal liver metastases treated by either HR or RFA.

RESULTS

Forty-two patients underwent HR and 25 patients underwent RFA. The 5-year overall and local recurrence-free survival rates after HR (50.1% and 89.7%, respectively) were higher than after RFA (25.5% and 69.7%, respectively) (P = .0263 and .028, respectively). In small tumors less than 3 cm (n = 38), the 5-year survival rates between HR and RFA were similar, including overall (56.1% vs 55.4%, P = .451) and local recurrence-free (95.7% vs 85.6%, P = .304) survival rates. On multivariate analysis, tumor size, metastases treatment, and primary node status were significant prognostic factors.

CONCLUSIONS

HR had better outcomes than RFA for recurrence and survival after treatment of solitary colorectal liver metastases. However, in tumors smaller than 3 cm, RFA can be recommended as an alternative treatment to patients who are not candidates for surgery because the liver metastases is poorly located anatomically, the functional hepatic reserve after a resection would be insufficient, the patient's comorbidity inhibits a major surgery, or extrahepatic metastases are present.

Percutaneous radiofrequency ablation of liver cancer in the hepatic dome using the intrapleural fluid infusion technique

BACKGROUND

Intrapleural fluid infusion improves ultrasonographic visualization of tumours in the hepatic dome. The aim of this study was to assess the safety and long-term efficacy of ultrasonographically guided percutaneous radiofrequency ablation for tumours in the hepatic dome with intrapleural infusion.

METHODS

Of 2575 patients with hepatocellular carcinoma or hepatic metastases treated with radiofrequency ablation, intrapleural fluid infusion was performed in 587 patients for tumours in the hepatic dome. After the tip of a 14-G metallic needle was positioned in the pleural cavity under ultrasonographic guidance, 500-1000 ml of 5 per cent glucose solution was infused in 5-15 min. Radiofrequency ablation was performed using an internally cooled electrode. Long-term results were evaluated in 347 patients with a single hepatocellular carcinoma who were naive to any treatment.

RESULTS

Intrapleural fluid infusion was successfully performed in all 587 patients. The major complication rate on a per tumour basis was similar for patients treated with and without intrapleural infusion (1.6 versus 1.6 per cent; P = 0.924). The overall and recurrence-free survival were both similar for naive patients with a single hepatocellular carcinoma treated with and without intrapleural infusion (P = 0.429 and P = 0.109 respectively). Intrapleural infusion was not associated with lower overall survival in multivariable analysis.

CONCLUSION

With intrapleural fluid infusion, radiofrequency ablation for tumours in the hepatic dome was safe and effective, resulting in satisfactory overall and recurrence-free survival.

Current situation and progress of local ablation therapy for hepatocellular carcinoma

Local ablation therapy with satisfactory therapeutic effects has been an important combined therapy for hepatocellular carcinoma (HCC). There are mainly two ablation methods available including thermal ablation and chemical ablation. Thermal ablation techniques include microwave ablation, radiofrequency ablation, laser ablation, high intensity focus ultrasound (HIFU) and cryoablation, etc. Chemical ablation methods include mainly ethanol ablation and acetic acid ablation. In this article, our objective was to evaluate the current situation and progress of local ablation therapy in terms of its principles, indications, therapeutic effects, complications, contraindications and pros and cons of various ablation therapies for HCC.

CT-guided radiofrequency ablation in patients with hepatic metastases from breast cancer

The purpose of this study was to evaluate technical success, technique effectiveness, and survival following radiofrequency ablation for breast cancer liver metastases and to determine prognostic factors. Forty-three patients with 111 breast cancer liver metastases underwent CT-guided percutaneous radiofrequency (RF) ablation. Technical success and technique effectiveness was evaluated by performing serial CT scans. We assessed the prognostic value of hormone receptor status, overexpression of human epidermal growth factor receptor 2 (HER2), and presence of extrahepatic tumor spread. Survival rates were calculated using the Kaplan-Meier method. Technical success was achieved in 107 metastases (96%). Primary technique effectiveness was 96%. During follow-up local tumor progression was observed in 15 metastases, representing a secondary technique effectiveness of 86.5%. The overall time to progression to the liver was 10.5 months. The estimated overall median survival was 58.6 months. There was no significant difference in terms of survival probability with respect to hormone receptor status, HER2 overexpression, and presence of isolated bone metastases. Survival was significantly lower among patients with extrahepatic disease, with the exception of skeletal metastases. We conclude that CT-guided RF ablation of liver metastases from breast cancer can be performed with a high degree of technical success and technique effectiveness, providing promising survival rates in patients with no visceral extrahepatic disease. Solitary bone metastases did not negatively affect survival probability after RF ablation.

Beneficial effects of hypnosis and adverse effects of empathic attention during percutaneous tumor treatment: when being nice does not suffice

PURPOSE

To determine how hypnosis and empathic attention during percutaneous tumor treatments affect pain, anxiety, drug use, and adverse events.

MATERIALS AND METHODS

For their tumor embolization or radiofrequency ablation, 201 patients were randomized to receive standard care, empathic attention with defined behaviors displayed by an additional provider, or self-hypnotic relaxation including the defined empathic attention behaviors. All had local anesthesia and access to intravenous medication. Main outcome measures were pain and anxiety assessed every 15 minutes by patient self-report, medication use (with 50 mug fentanyl or 1 mg midazolam counted as one unit), and adverse events, defined as occurrences requiring extra medical attention, including systolic blood pressure fluctuations (> or =50 mm Hg change to >180 mm Hg or <105 mm Hg), vasovagal episodes, cardiac events, and respiratory impairment.

RESULTS

Patients treated with hypnosis experienced significantly less pain and anxiety than those in the standard care and empathy groups at several time intervals and received significantly fewer median drug units (mean, 2.0; interquartile range [IQR], 1-4) than patients in the standard (mean, 3.0; IQR, 1.5-5.0; P = .0147) and empathy groups (mean, 3.50; IQR, 2.0-5.9; P = .0026). Thirty-one of 65 patients (48%) in the empathy group had adverse events, which was significantly more than in the hypnosis group (eight of 66; 12%; P = .0001) and standard care group (18 of 70; 26%; P = .0118).

CONCLUSIONS

Procedural hypnosis including empathic attention reduces pain, anxiety, and medication use. Conversely, empathic approaches without hypnosis that provide an external focus of attention and do not enhance patients' self-coping can result in more adverse events. These findings should have major implications in the education of procedural personnel.

Radiofrequency ablation of colorectal liver metastases: small size favorably predicts technique effectiveness and survival

The objective of this study was to analyze long-term results of radiofrequency thermal ablation (RFA) for colorectal metastases (MTS), in order to evaluate predictors for adverse events, technique effectiveness, and survival. One hundred ninety-nine nonresectable MTS (0.5-8 cm; mean, 2.9 cm) in 122 patients underwent a total of 166 RFA sessions, percutaneously or during surgery. The technique was "simple" or "combined" with vascular occlusion. The mean follow-up time was 24.2 months. Complications, technique effectiveness, and survival rates were statistically analyzed. Adverse events occurred in 8.1% of lesions (major complication rate: 1.1%), 7.1% with simple and 16.7% with combined technique (p = 0.15). Early complete response was obtained in 151 lesions (81.2%), but 49 lesions (26.3%) recurred locally after a mean of 10.4 months. Sustained complete ablation was achieved in 66.7% of lesions < or = 3 cm versus 33.3% of lesions > 3 cm (p < 0.0001). Survival rates at 1, 3, and 5 years were 91%, 54%, and 33%, respectively, from the diagnosis of MTS and 79%, 38%, and 22%, respectively, from RFA. Mean survival time from RFA was 31.5 months, 36.2 in patients with main MTS < or = 3 cm and 23.2 in those with at least one lesion > 3 cm (p = 0.006). We conclude that "simple" RFA is safe and successful for MTS < or = 3 cm, contributing to prolong survival when patients can be completely treated.

Cost of radiofrequency ablation in the treatment of hepatic malignancies

OBJECTIVES

Our primary objective was to assess the cost of radio-frequency ablation (RFA) of hepatic malignancies and to compare it to hospital reimbursement paid in the French Prospective Payment System (PPS).

PATIENTS AND METHODS

A series of 305 patients were enrolled into a prospective study. All resources used during the RFA-related hospital stay were recorded. Costs were assessed from the perspective of the health care providers and computed for four groups of patients: percutaneous RFA in an outpatient setting (group Ia, N=44), percutaneous RFA in an inpatient setting (group Ib, N=94), laparoscopic RFA (group II, N=44) and intraoperative RFA combined with resection (group III, N=120).

RESULTS

Mean hospital costs were estimated at euro 1581 (group Ia), euro 3824 (group Ib), euro 8194 (group II) and euro 12967 (group III). Costs per stay without intensive care in these groups were respectively euro 1581, euro 3635, euro 6622 and euro 10905 and reimbursement (intensive care excluded) was euro 560, euro 3367, euro 9084 and euro 11780.

CONCLUSION

In the French PPS, the cost of RFA is covered by lump sums paid to hospitals exclusively for intraoperative and laparoscopic RFA. For percutaneous RFA, which is the most frequent approach, reimbursement is highly insufficient.