Radiofrequency ablation versus resection for colorectal cancer liver metastases: a meta-analysis

The Management of Oligometastatic Disease in Colorectal Cancer: Present Strategies and Future Perspectives

Oligometastatic disease has been described as an intermediate clinical state between localized cancer and systemically metastasized disease. Recent clinical studies have shown prolonged survival when aggressive locoregional approaches are added to systemic therapies in patients with oligometastases. The aim of this review is to outline the newest options to treat oligometastatic colorectal cancer (CRC), also considering its molecular patterns. We present an overview of the available local treatment strategies, including surgical procedures, stereotactic body radiation therapy (SBRT), thermal ablation, as well as trans-arterial chemoembolization (TACE) and selective internal radiotherapy (SIRT). Moreover, since imaging methods provide crucial information for the early diagnosis and management of oligometastatic CRC, we discuss the role of modern radiologic techniques in selecting patients that are amenable to potentially curative locoregional treatments.

Radiofrequency ablation in treatment of hepatic metastases of colorectal cancer

Radiofrequency ablation in treatment of hepatic metastases of colorectal cancer

Microwave ablation of colorectal liver metastases: Impact of a 10-mm safety margin on local recurrence in a tertiary care hospital

Microwave ablation (MWA) for colorectal liver metastasis (CLM) has been traditionally considered inferior to surgery due to the higher rate of local recurrence. The study investigated whether a safety margin of 10 mm can improve local control in patients undergoing surgical MWA. Surgical MWA was used to treat 53 lesions in 22 patients with CLM at our Institution from June 2012 to June 2017. The patients’ mean age was 64.5 years, and the median size of the lesion was 16.5 mm (9–34 mm). MWA was associated with liver resection in 16 patients (72.7%). The median follow-up was 32.4 months. Univariate and multivariate analyses were performed to identify factors associated with tumor recurrence. Median ablation area was 36.6 mm² (30–50 mm²). The complication rate was 22.7%. No local recurrence was observed during follow-up. Disease-free survival was 20 months (4.8–55.2 months). Univariate analysis revealed that the number of liver metastases and node-positive primary tumors were associated with tumor recurrence. Multivariate analysis revealed that node-positive primary tumor was the only factor significantly associated with tumor recurrence (p = 0.049; odds ratio, 12; 95% confidence interval, 1–143). When performed with a 10-mm safety margin, surgical MWA can lead to acceptable oncological outcomes with low morbidity. Therefore, it represents a good option in selected patients with CLM.

A novel use of biomechanical model-based deformable image registration (DIR) for assessing colorectal liver metastases ablation outcomes

Purpose:

Colorectal cancer is the third most common form of cancer in the United States, and up to 60% of these patients develop liver metastasis. While hepatic resection is the curative treatment of choice, only 20% of patients are candidates at the time of diagnosis. While percutaneous thermal ablation (PTA) has demonstrated 24%–51% overall 5-year survival rates, assurance of sufficient ablation margin delivery (5 mm) can be challenging, with current methods of 2D distance measurement not ensuring 3D minimum margin. We hypothesized that biomechanical model-based deformable image registration (DIR) can reduce spatial uncertainties and differentiate local tumor progression (LTP) patients from LTP-free patients.

Methods:

We retrospectively acquired 30 patients (16 LTP and 14 LTP-free) at our institution who had undergone PTA and had a contrast-enhanced pre-treatment and post-ablation CT scan. Liver, disease, and ablation zone were manually segmented. Biomechanical model-based DIR between the pre-treatment and post-ablation CT mapped the gross tumor volume onto the ablation zone and measured 3D minimum delivered margin (MDM). An in-house cone-tracing algorithm determined if progression qualitatively collocated with insufficient 5 mm margin achieved.

Results:

Mann–Whitney U test showed a significant difference (p < 0.01) in MDM from the LTP and LTP-free groups. A total of 93% (13/14) of patients with LTP had a correlation between progression and missing 5 mm of margin volume.

Conclusions:

Biomechanical DIR is able to reduce spatial uncertainty and allow measurement of delivered 3D MDM. This minimum margin can help ensure sufficient ablation delivery, and our workflow can provide valuable information in a clinically useful timeframe.

Thermal Ablation Compared to Partial Hepatectomy for Recurrent Colorectal Liver Metastases: An Amsterdam Colorectal Liver Met Registry (AmCORE) Based Study

Simple Summary

Between 64 and 85% of patients with colorectal liver metastases (CRLM) develop distant intrahepatic recurrence after curative intent local treatment. The current standard of care for new CRLM is repeat local treatment, comprising partial hepatectomy and thermal ablation. Although relatively safe and feasible, repeat partial hepatectomy can be challenging due to adhesions and due to the reduced liver volume after surgery. This AmCORE based study assessed safety, efficacy and survival outcomes of repeat thermal ablation as compared to repeat partial hepatectomy in patients with recurrent CRLM. Repeat partial hepatectomy was not different from repeat thermal ablation with regard to survival, distant- and local recurrence rates and complications, whereas length of hospital stay favored repeat thermal ablation. Thermal ablation should be considered a valid and potentially less invasive alternative in the treatment of recurrent new CRLM, while the eagerly awaited results of the COLLISION trial (NCT03088150) should provide definitive answers regarding surgery versus thermal ablation for CRLM.

Abstract

The aim of this study was to assess safety, efficacy and survival outcomes of repeat thermal ablation as compared to repeat partial hepatectomy in patients with recurrent colorectal liver metastases (CRLM). This Amsterdam Colorectal Liver Met Registry (AmCORE) based study of two cohorts, repeat thermal ablation versus repeat partial hepatectomy, analyzed 136 patients (100 thermal ablation, 36 partial hepatectomy) and 224 tumors (170 thermal ablation, 54 partial hepatectomy) with recurrent CRLM from May 2002 to December 2020. The primary and secondary endpoints were overall survival (OS), distant progression-free survival (DPFS) and local tumor progression-free survival (LTPFS), estimated using the Kaplan–Meier method, and complications, analyzed using the chi-square test. Multivariable analyses based on Cox proportional hazards model were used to account for potential confounders. In addition, subgroup analyses according to patient, initial and repeat local treatment characteristics were performed. In the crude overall comparison, OS of patients treated with repeat partial hepatectomy was not statistically different from repeat thermal ablation (p = 0.927). Further quantification of OS, after accounting for potential confounders, demonstrated concordant results for repeat local treatment (hazard ratio (HR), 0.986; 95% confidence interval (CI), 0.517–1.881; p = 0.966). The 1-, 3- and 5-year OS were 98.9%, 62.6% and 42.3% respectively for the thermal ablation group and 93.8%, 74.5% and 49.3% for the repeat resection group. No differences in DPFS (p = 0.942), LTPFS (p = 0.397) and complication rate (p = 0.063) were found. Mean length of hospital stay was 2.1 days in the repeat thermal ablation group and 4.8 days in the repeat partial hepatectomy group (p = 0.009). Subgroup analyses identified no heterogeneous treatment effects according to patient, initial and repeat local treatment characteristics. Repeat partial hepatectomy was not statistically different from repeat thermal ablation with regard to OS, DPFS, LTPFS and complications, whereas length of hospital stay favored repeat thermal ablation. Thermal ablation should be considered a valid and potentially less invasive alternative for small-size (0–3 cm) CRLM in the treatment of recurrent new CRLM. While, the eagerly awaited results of the phase III prospective randomized controlled COLLISION trial (NCT03088150) should provide definitive answers regarding surgery versus thermal ablation for CRLM.

Hospital variation in combined liver resection and thermal ablation for colorectal liver metastases and impact on short-term postoperative outcomes: a nationwide population-based study

BACKGROUND

Combining resection and thermal ablation can improve short-term postoperative outcomes in patients with colorectal liver metastases (CRLM). This study assessed nationwide hospital variation and short-term postoperative outcomes after combined resection and ablation.

METHODS

In this population-based study, all CRLM patients who underwent resection in the Netherlands between 2014 and 2018 were included. After propensity score matching for age, ASA-score, Charlson-score, diameter of largest CRLM, number of CRLM and earlier resection, postoperative outcomes were compared. Postoperative complicated course (PCC) was defined as discharge after 14 days or a major complication or death within 30 days of surgery.

RESULTS

Of 4639 included patients, 3697 (80%) underwent resection and 942 (20%) resection and ablation. Unadjusted percentage of patients who underwent resection and ablation per hospital ranged between 4 and 44%. Hospital variation persisted after case-mix correction. After matching, 734 patients remained in each group. Hospital stay (median 6 vs. 7 days, p = 0.011), PCC (11% vs. 14.7%, p = 0.043) and 30-day mortality (0.7% vs. 2.3%, p = 0.018) were lower in the resection and ablation group. Differences faded in multivariable logistic regression due to inclusion of major hepatectomy.

CONCLUSION

Significant hospital variation was observed in the Netherlands. Short-term postoperative outcomes were better after combined resection and ablation, attributed to avoiding complications associated with major hepatectomy.

Hepatic thermal injury promotes colorectal cancer engraftment in C57/black 6 mice

Treatment options for liver metastases (primarily colorectal cancer) are limited by high recurrence rates and persistent tumor progression. Surgical approaches to management of these metastases typically use heat energy including electrocautery, argon beam coagulation, thermal ablation of surgical margins for hemostasis, and preemptive thermal ablation to prevent bleeding or to effect tumor destruction. Based on high rates of local recurrence, these studies assess whether local effects of hepatic thermal injury (HTI) might contribute to poor outcomes by promoting a hepatic microenvironment favorable for tumor engraftment or progression due to induction of procancer cytokines and deleterious immune infiltrates at the site of thermal injury. To test this hypothesis, an immunocompetent mouse model was developed wherein HTI was combined with concomitant intrasplenic injection of cells from a well-characterized MC38 colon carcinoma cell line. In this model, HTI resulted in a significant increase in engraftment and progression of MC38 tumors at the site of thermal injury. Furthermore, there were local increases in expression of messenger ribonucleic acid (mRNA) for hypoxia-inducible factor-1α (HIF1α), arginase-1, and vascular endothelial growth factor α and activation changes in recruited macrophages at the HTI site but not in untreated liver tissue. Inhibition of HIF1α following HTI significantly reduced discreet hepatic tumor development (P = 0.03). Taken together, these findings demonstrate that HTI creates a favorable local environment that is associated with protumorigenic activation of macrophages and implantation of circulating tumors. Discrete targeting of HIF1α signaling or inhibiting macrophages offers potential strategies for improving the outcome of surgical management of hepatic metastases where HTI is used.

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.

Clinical impact of radiofrequency ablation and stereotactic body radiation therapy for colorectal liver metastasis as local therapies for elderly, vulnerable patients

Background and Aim

Surgical resection is the standard local therapy for patients with colorectal liver metastases (CRLM). However, elderly and vulnerable patients sometimes have various organ dysfunctions. We have to conduct nonsurgical local therapies for those patients who might not tolerate surgery or systemic chemotherapy.

Methods

We retrospectively reviewed medical records of 254 patients who underwent local therapies, including surgery, radiofrequency ablation (RFA), and stereotactic body radiation therapy (SBRT), for CRLM from January 2010 to December 2016, at seven tertiary‐care institutions in Japan. This study was designed to include elderly, vulnerable patients who received local therapy for CRLM. For those undergoing liver resection, only those having one or more points of the Charlson comorbidity index (CCI) were enrolled.

Results

Of the total 169 enrolled patients, 122 patients underwent surgery, 42 RFA, and 5 SBRT as the first local therapy for CRLM. Median overall survival from the first local therapy was 5.9 years for the surgery group, 2.7 years for the RFA group, and 3.8 years for the SBRT group. The proportion of the patients with CCI ≧3 was significantly higher in the group of RFA/SBRT than surgery (P < 0.0001). In selected patients with CCI ≧3, there was no difference of the median survival time between the surgery group and the RFA group.

Conclusions

We could have other treatment options to provide nonsurgical local therapies (RFA/SBRT) for elderly, vulnerable CRLM patients who have risks for surgery.

Management of Liver Oligometastatic Esophageal Cancer: Overview and Critical Analysis of the Different Loco-Regional Treatments

Esophageal cancer (EC) is an aggressive disease that is associated with a poor prognosis. Since metastastic EC is usually considered suitable only for palliative therapy with an estimated 5-year overall survival (OS) less than 5%, the optimal management of patients with liver oligometastatic EC (LOEC) is still undefined. The aim of this review is to provide an overview of the different treatment options for LOEC. A literature search was conducted using PubMed, Embase, and Cochrane to identify articles evaluating different treatment strategies for LOEC. Among 828 records that were identified, 20 articles met the inclusion criteria. These studies included patients who have undergone any type of surgical procedure and/or loco-regional therapy. Liver resection resulted in the best survival for patients with low tumor burden (3 lesions): 5-year OS 30–50% versus 8–12% after only chemotherapy (CHT). The 5-year OS of loco-regional therapies was 23% with a local recurrence risk ranging 0–8% for small lesions (2 to 3 cm). An aggressive multidisciplinary approach for LOEC patients may improve survival. Surgery seems to be the treatment of choice for resectable LOEC. If unfeasible, loco-regional therapies may be considered. In order to better select these patients and offer a chance of cure, prospective trials and a definition of treatment protocols are needed.

Ablation or Resection for Colorectal Liver Metastases? A Systematic Review of the Literature

Background: Successful use of ablation for small hepatocellular carcinomas (HCC) has led to interest in the role of ablation for colorectal liver metastases (CRLM). However, there remains a lack of clarity about the use of ablation for colorectal liver metastases (CRLM), specifically its efficacy compared with hepatic resection. Methods: A systematic review of the literature on ablation or resection of colorectal liver metastases was performed using MEDLINE, Cochrane Library, and Embase until December 2018. The aim of this study was to summarize the evidence for ablation vs. resection in the treatment of CRLM. Results: This review identified 1,773 studies of which 18 were eligible for inclusion. In the majority of the studies, overall survival (OS) and disease-free survival (DFS) were significantly higher and local recurrence (LR) rates were significantly lower in the resection groups. On subgroup analysis of solitary CRLM, resection was associated with improved OS, DFS, and reduced LR. Three series assessed the outcome of resection vs. ablation for technically resectable CRLM, and showed improved outcome in the resection group. In fact, there were no studies showing a survival advantage of ablation compared to resection in the treatment of CRLM. Conclusions: Resection remains the "gold standard" in the treatment of CRLM and should not be replaced by ablation at present. This review supports the use of ablation only as an adjunct to resection and as a single treatment option when resection is not safely possible.

Factors predicting ablation site recurrence following percutaneous microwave ablation of colorectal hepatic metastases

BACKGROUND

Microwave ablation (MWA) is a recognised treatment option for liver metastases. The size of the tumour is a well-established factor that influences the success of MWA. However, the effect of "heat sink" on the success of MWA for hepatic metastases is unclear. The aim of this study was to determine whether heat sink effect is a factor that contributes to ablation site recurrence (ASR).

METHODS

A prospectively maintained database of patients who underwent percutaneous MWA for treatment of colorectal liver metastases was analysed. Imaging and demographic characteristics were compared between metastases that recurred following ablation and those that did not. Proximity to a large hepatic vein was defined as <10 mm.

RESULTS

126 ablations in 87 patients met the inclusion criteria and were studied over a median follow-up period of 28 (12-75) months. ASR was detected in 43 ablations (34%) and was associated with clinical risk score (CRS) ≥2 (OR 2.2 95% CI 1.3-3.3, p = 0.029), metastasis size (OR 0.953 95% CI (0.929-0.978), p < 0.001) and proximity to a large hepatic vein (OR 7.5 95%CI 2.4-22.8, p < 0.001). Proximity to a large hepatic vein was not associated with reduced overall survival (OS) but was associated with liver-specific recurrence (HR 4.7 95%CI 1.7-12.5, p = 0.004).

CONCLUSIONS

In addition to tumour size proximity to large hepatic venous structures is an independent predictor of ASR and liver-specific recurrence following MWA. However, this was not associated with overall survival.

Videolaparoscopic microwave ablation in patients with HCC at a European high-volume center: Results of 815 procedures

BACKGROUND

Videolaparoscopic (VL) microwave ablation (MWA) is not included in most of the international guidelines as a therapeutic option for hepatocellular carcinoma (HCC). Aim of this study was to assess the safety of VL MWA in patients with HCC for whom resection or percutaneous ablation is unsuitable.

METHODS

A retrospective analysis was performed on a prospective database of patients with HCC treated with VL MWA at our institution from 2009 to 2016. Patient demographics, operational characteristics, and complications were recorded. Statistical analysis was performed to identify safety profile, overall survival and recurrence rate.

RESULTS

A total of 815 VL MWA were performed in 674 patients with a mean age of 64 years. Patients had a mean Model for End-stage Liver Disease score of 10 (±3); 32.8% were Child B, 44.1% Barcelona Clinic Liver Cancer B-C. Perioperative mortality was 0.4%. Overall morbidity was 30.8%, with Dindo-Clavien complications ≥3 in 2%. The median length of stay was 2 days. In 43.1% VL MWA was the first-line therapy. Overall 1-, 3-, and 5-year survival rates were 81.9%, 54.9%, and 35.9%.

CONCLUSIONS

The present is the largest series of VL ablation and the bigger number of patients with HCC treated with MW reported nowadays. It confirms the safety of a minimally invasive procedure for patients with HCC when resection or percutaneous ablation is not feasible.

The value of KRAS gene status in predicting local tumor progression of colorectal liver metastases following radiofrequency ablation

PURPOSE

We investigated the relationships between KRAS gene status and local tumor progression (LTP) of colorectal liver metastases (CLMs) after treatment with percutaneous ultrasound-guided radiofrequency ablation (RFA).

MATERIALS AND METHODS

Clinical and imaging data from 76 patients (154 lesions) with CLM who underwent percutaneous ultrasound-guided RFA and had KRAS gene test results between January 2012 and June 2016 were analyzed. The average lesion size was 2.3 ± 1.0 cm (range 0.9-5.7 cm); 38 cases (82 lesions) had wild-type KRAS, and 38 cases (72 lesions) had KRAS mutations.

RESULTS

The technique effectiveness was 98.1% (151/154), and the LTP rate was 18.2% (28/154) after RFA, which was performed between January 2012 and November 2017. The mean and median follow-up were 32.7 ± 2.5 and 32.0 ± 2.6 months (range 1-70 months), respectively. Cumulative LTP rates at 6 months and 1, 2 and 3 years post-RFA for all patients were 7.4, 14.5, 17.8 and 19.2%, respectively. The LTP rate for patients with mutant KRAS (27.8% [20/72]) was significantly higher than that in patients with wild-type KRAS (9.8% [8/82]; p = .004). The cumulative LTP rates at 6 months and 1, 2 and 3 years post-RFA were 4.0, 11.1, 11.1 and 11.1%, respectively, for patients with wild-type KRAS and 11.2, 18.4, 25.2 and 36.2%, respectively, for patient with mutant KRAS (p = .011). Univariate (p = .011) and multivariate analyses (p = .005) showed that KRAS genotype in liver metastases was predictive of LTP. Multivariate analysis also showed that ablation margin size (p< .001) and modified clinical risk score (CRS; p = .033) were independent prognostic factors for LTP.

CONCLUSIONS

KRAS gene status of liver metastatic lesions was associated with LTP rates after RFA of CLM. Ablation margin size and modified CRS were also independent prognostic factors for LTP.

The role of interventional oncology in the treatment of colorectal cancer liver metastases

Colorectal cancer is a leading cause of death both in Europe and worldwide. Unfortunately, 20-25% of patients with colorectal cancer already have metastases at the time of diagnosis, while 50-60% of the remainder will develop metastases later during the course of the disease. Although hepatic excision is the first-line treatment for patients with liver-limited colorectal metastases and is reported to prolong the survival of these patients, few patients are candidates. Locoregional therapy encompasses minimally invasive techniques practiced by interventional radiology. Most widely used locoregional therapies include ablative treatments (radiofrequency ablation, microwave ablation) and transcatheter intra-arterial therapies (transarterial chemoembolization, and radioembolization with yttrium-90).

The role of interventional oncology in the treatment of colorectal cancer liver metastases

Colorectal cancer is a leading cause of death both in Europe and worldwide. Unfortunately, 20-25% of patients with colorectal cancer already have metastases at the time of diagnosis, while 50-60% of the remainder will develop metastases later during the course of the disease. Although hepatic excision is the first-line treatment for patients with liver-limited colorectal metastases and is reported to prolong the survival of these patients, few patients are candidates. Locoregional therapy encompasses minimally invasive techniques practiced by interventional radiology. Most widely used locoregional therapies include ablative treatments (radiofrequency ablation, microwave ablation) and transcatheter intra-arterial therapies (transarterial chemoembolization, and radioembolization with yttrium-90).

Radiofrequency and Microwave Ablation Compared to Systemic Chemotherapy and to Partial Hepatectomy in the Treatment of Colorectal Liver Metastases: A Systematic Review and Meta-Analysis

Purpose

To assess safety and outcome of radiofrequency ablation (RFA) and microwave ablation (MWA) as compared to systemic chemotherapy and partial hepatectomy (PH) in the treatment of colorectal liver metastases (CRLM).

Methods

MEDLINE, Embase and the Cochrane Library were searched. Randomized trials and comparative observational studies with multivariate analysis and/or matching were included. Guidelines from National Guideline Clearinghouse and Guidelines International Network were assessed using the AGREE II instrument.

Results

The search revealed 3530 records; 328 were selected for full-text review; 48 were included: 8 systematic reviews, 2 randomized studies, 26 comparative observational studies, 2 guideline-articles and 10 case series; in addition 13 guidelines were evaluated. Literature to assess the effectiveness of ablation was limited. RFA + systemic chemotherapy was superior to chemotherapy alone. PH was superior to RFA alone but not to RFA + PH or to MWA. Compared to PH, RFA showed fewer complications, MWA did not. Outcomes were subject to residual confounding since ablation was only employed for unresectable disease.

Conclusion

The results from the EORTC-CLOCC trial, the comparable survival for ablation + PH versus PH alone, the potential to induce long-term disease control and the low complication rate argue in favour of ablation over chemotherapy alone. Further randomized comparisons of ablation to current-day chemotherapy alone should therefore be considered unethical. Hence, the highest achievable level of evidence for unresectable CRLM seems reached. The apparent selection bias from previous studies and the superior safety profile mandate the setup of randomized controlled trials comparing ablation to surgery.

Electronic supplementary material

The online version of this article (10.1007/s00270-018-1959-3) contains supplementary material, which is available to authorized users.

Radiofrequency ablation is beneficial in simultaneous treatment of synchronous liver metastases and primary colorectal cancer

Background

In patients with resectable synchronous colorectal liver metastases (CRLM), either two-staged or simultaneous resections of the primary tumor and liver metastases are performed. Data on radiofrequency ablation (RFA) for the treatment of CRLM during a simultaneous procedure is lacking. The primary aim was to analyze short-term and long-term outcome of RFA in simultaneous treatment. A secondary aim was to compare simultaneous resection with the colorectal-first approach.

Methods

Retrospective analysis of 241 patients with colorectal cancer and synchronous CRLM between 2000–2016. Median follow-up was 36.1 months (IQR 18.2–58.8 months). A multivariable analysis was performed to analyze the postoperative morbidity, using the comprehensive complication index. A propensity matched analysis was performed to compare survival rates.

Results

In multivariable analysis, the best predictor of lower complication severity was treatment with RFA (p = 0.040). Higher complication rates were encountered in patients who underwent an abdominoperineal resection (p = 0.027) or age > 60 years (p = 0.022). The matched analysis showed comparable overall survival in RFA treated patients versus patients undergoing a liver resection with a five year overall survival of 39.4% and 37.5%, respectively (p = 0.782). In a second matched analysis, 5-year overall survival rates in simultaneously treated patients (43.8%) was comparable to patients undergoing the colorectal first approach (43.0%, p = 0.223).

Conclusions

RFA treatment of CRLM in simultaneous procedures is associated with a lower complication severity and non-inferior oncological outcome as compared to partial liver resection. RFA should be considered a useful alternative to liver resection.

Evaluation of Effects of Radiofrequency Ablation of Ex vivo Liver Using the 1-Fr Wire Electrode

BACKGROUND AND STUDY AIMS

Percutaneous and intraoperative radiofrequency ablation (RFA) has become a valued tool in the management of primary and secondary hepatic lesions. A recent FDA-approved endoscopic ultrasound (EUS)-guided RFA probe now offers promise to help manage such lesions. However, there are no data to determine the ideal power setting and duration of ablation needed to effectively treat hepatic masses. The aim of the study was to evaluate the macroscopic zone of hepatic injury for EUS-RFA using a variety of settings within a fresh porcine hepatic specimen.

METHODS

RFA was performed using the Habib EUS-RFA needle (EMcision Ltd, London, UK) which is a 1-Fr wire (0.33 mm, 0.013 inch) with a working length of 190 cm. A step by step approach to deliver radiofrequency energy at 5, 10, 15, 20, and 50 W of power and 10, 30, 60, 90, 120, and 300 seconds, respectively, was followed. Macroscopic and microscopic findings of the ablation zone were evaluated at each setting.

RESULTS

The maximal zone (diameter, 8.2±0.14 mm; length, 20.85±0.21 mm) of coagulative necrosis was achieved using an ablation power of 10 W for duration of 90 seconds. Notably, increased power settings resulted in an unexpected and diminished effect on tissue destruction.

CONCLUSIONS

Our findings support the use of 10 W power for 90 seconds for maximum ablation in the liver. Our data also provide initial guidance and alternate settings to be considered when performing EUS-RFA to adjust the ablation power and duration to match the lesion size, shape, and risk of injury to adjacent structures.

Radiofrequency ablation for colorectal cancer liver metastases initially greater than 25 mm but downsized by neo-adjuvant chemotherapy is associated with increased rate of local tumor progression

BACKGROUND

Radiofrequency ablation (RFA) is a valid treatment for liver metastases from colorectal cancer (CRLM) smaller than 25 mm and unsuitable for surgical resection. Tumor size is predictive for local tumor progression (LTP). The aim of this study was to evaluate whether RFA is indicated for lesions >25 mm at presentation but <25 mm after chemotherapy.

METHOD

Patients who underwent RFA for CRLM after chemotherapy (January 2004-December 2012) were reviewed. Metastases were classified according to their size. Group 1: ≤25 mm before and after chemotherapy. Group 2A: >25 mm before but ≤25 mm after chemotherapy. Group 2B: >25 mm before and after chemotherapy.

RESULTS

133 CRLM were ablated in 83 patients (median follow-up 56 months). At 1-year, the LTP rate was higher in group 2A than in group 1 (32% vs. 16%, p ≤ 0.001). The highest rate of 1-year LTP was 64% in group 2B. Time to LTP (TLTP) was shorter in group 2A than in group 1 (HR: 2.89; 95% CI [1.04-8.01]; p = 0.004). Following multivariate analysis, the group type was the only predictive factor for TLTP (p < 0.001).

CONCLUSIONS

RFA is not the optimal treatment for CRLM > 25 mm at presentation.

An Overview of the Current Management of Bilobar Colorectal Liver Metastases

Bilobar colorectal liver metastases (BCRLM) present a challenging scenario for liver surgeons globally. The following article aims to provide an overview of the different strategies which may be utilised in order to successfully manage advanced BCRLM.

Radiofrequency ablation compared to surgical resection for curative treatment of patients with colorectal liver metastases - a meta-analysis

BACKGROUND

Hepatic resection and ablative treatments, such as RFA are available treatment options for liver tumors. Advantages and disadvantages of these treatment options in patients with colorectal liver metastases need further evaluation. The purpose of this study was to systematically evaluate the role of radiofrequency ablation (RFA) compared to surgery in the curative treatment of patients with colorectal liver metastases (CRLM).

METHODS

A systematic search was performed from MEDLINE, EMBASE and the Cochrane Library for studies directly comparing RFA with resection for CRLM, after which variables were evaluated.

RESULTS

RFA had significantly lower complication rates (OR = 0.44, 95% CI = 0.26-0.75, P = 0.002) compared to resection. However, RFA showed a higher rate of any recurrence (OR = 1.66, 95% CI = 1.15-2.40, P = 0.007), local recurrence (OR = 9.56, 95% CI = 6.85-13.35, P = 0.001), intrahepatic recurrence (OR = 1.96, 95% CI = 1.34-2.87, P = 0.001) and extrahepatic recurrence (OR = 1.21, 95% CI = 0.90-1.63, P = 0.22). Also, 5-year disease-free survival (OR = 2.20, 95% CI = 1.28-3.79, P = 0.005) and overall survival (OR = 2.35, 95% CI = 1.49-3.69, P = 0.001) were significantly lower in patients treated with RFA.

CONCLUSIONS

RFA showed a significantly lower rate of complications, but also a lower survival and a higher rate of recurrence as compared to surgical resection. All the included studies were subject to possible patient selection bias and therefore randomized clinical trials are needed to accurately evaluate these treatment modalities.

Endoscopic Radiofrequency Ablation of the Pancreas

Radiofrequency ablation (RFA) is a well-established technique to ablate dysplastic and neoplastic tissue via local thermal coagulative necrosis. Despite the widespread use in management of several cancers, the application of RFA in pancreas has been limited due to the increased risks of complications from the increased sensitivity of pancreatic tissue to thermal injury and proximity to vascular and biliary structures. RFA has been successfully used during laparotomy for locally advanced pancreatic carcinoma but requires an invasive approach. Endoscopic ultrasound-guided RFA offers the best combination of excellent visualization, real-time imaging guidance, and precise localization with minimal invasiveness. Several animal and human studies have demonstrated the technical feasibility and safety of endoscopic RFA in the pancreas. This article provides a comprehensive review of endoscopic RFA in the management of pancreatic lesions.

Radiofrequency Ablation versus Liver Resection for Colorectal Cancer Liver Metastasis: An Updated Systematic Review and Meta-analysis

Background:

Controversial results about the therapeutic value of radiofrequency ablation (RFA) and liver resection (LR) in the treatment of colorectal cancer liver metastasis (CRCLM) have been reported. Thus, we performed the present meta-analysis to summarize the related clinical evidences.

Methods:

A systematic literature search was conducted using PubMed (Medline), EMBASE, Cochrane Library, and Web of Science, for all years up to April 2016. Pooled analyses of the overall survival (OS), progression-free survival (PFS), and morbidity rates were performed.

Results:

A total of 14 studies were finally enrolled in the meta-analysis. Patients treated by LR gained a longer OS and PFS than those of patients treated by RFA. Patients in the RFA group had lower morbidity rates than those of patients in the LR group. Publication bias analysis revealed that there was no significant publication bias in the meta-analysis.

Conclusions:

Patients with CRCLM gained much more survival benefits from LR than that from RFA. RFA rendered lower rates of morbidities. More well-designed randomized controlled trails comparing the therapeutic value of LR and RFA are warranted.

Microwave ablation of liver malignancies: comparison of effects and early outcomes of percutaneous and intraoperative approaches with different liver conditions : New advances in interventional oncology: state of the art

Liver thermal ablation is an alternative treatment for hepatocellular carcinoma (HCC) and secondary liver malignancies. Microwave ablation (MWA) produces large ablation zones (AZ) in short time; however, AZ prediction is based on preclinical ex vivo models, rising concerns about reproducibility and safety in humans. We aimed to investigate the effects produced by a new-generation MWA system on human liver in vivo with different approaches (percutaneous or intraoperative) and liver conditions (cirrhosis or previous chemotherapy treatment), in comparison with manufacturer-provided predictions based on ex vivo animal models. Complete tumor ablation (CA) and early clinical outcomes were also assessed. From October 2014, 60 consecutive patients (cirrhotic = 31; non-cirrhotic = 10; chemotherapy-treated = 19) with 81 liver nodules (HCC = 31; mets = 50) underwent MWA procedures (percutaneous = 30; laparotomic = 18; laparoscopic = 12), with a 2450 MHz/100 W generator with Thermosphere™ Technology (Emprint™, Medtronic). A contrast-enhanced CT or MR was performed after one month to assess CA and measure AZ. A linear correlation between AZ volumes and ablation times was observed in vivo, without differences from manufacturer-provided ex vivo predictions in all operative approaches and liver conditions. Other independent variables (sex, age, nodule location) showed no relationship when added to the model. Median (IQR) longitudinal and transverse roundness-indexes of the AZs were, respectively, 0.77(0.13) and 0.93(0.11). CA at 1 month was 93% for percutaneous and 100% for intraoperative procedures (p = 0.175). Thirty-day morbidity and mortality were 3% and 0%. MWA with Thermosphere™ Technology produces predictable AZs on human liver in vivo, according to manufacturer-provided ex vivo predictions. In our experience, this new-generation MWA system is effective and safe to treat liver malignancies in different operative and clinical settings.

Long-term outcomes of radiofrequency ablation combined with hepatectomy compared with hepatectomy alone for colorectal liver metastases

Background

Combining radiofrequency ablation (RFA) with hepatectomy may enable treatment with curative intent for patients with colorectal liver metastasis (CRLM). However, the oncological outcomes in comparison with resection alone remain to be clarified.

Methods

Patients who underwent a first hepatectomy between 2001 and 2012 for CRLM were enrolled. Short- and long-term outcomes of patients who underwent hepatectomy plus RFA were compared with those of patients who had hepatectomy alone using propensity score matching.

Results

Of a total of 553 patients, hepatectomy + RFA and hepatectomy alone were performed in 37 and 516 respectively. Before matching, patients in the hepatectomy + RFA group were characterized primarily by a larger tumour burden. After matching of 31 patients who underwent hepatectomy + RFA with 93 who had hepatectomy alone, background characteristics were well balanced. In the matched cohort, overall and disease-free survival in the hepatectomy + RFA group were no different from those among patients who had hepatectomy alone (5-year overall survival rate 57 versus 61 per cent, P = 0·649; 5-year disease-free survival rate 19 versus 17 per cent, P = 0·865). Local recurrence at the ablated site was observed in four of 31 patients (13 per cent). Although overall local recurrence (ablated site and/or cut surface) was more frequent in the hepatectomy + RFA group (9 of 31 (29 per cent) versus 11 of 93 (12 per cent); P = 0·032), there was no difference in intrahepatic disease-free survival between the two groups (P = 0·705).

Conclusion

Hepatectomy + RFA achieved outcomes comparable to hepatectomy alone. Combining RFA with hepatectomy should be considered as an option to achieve cure.

Percutaneous thermal ablation for the treatment of colorectal liver metastases and hepatocellular carcinoma: a comparison of local therapeutic efficacy

AIM

This study aimed to compare the local therapeutic efficacy of percutaneous thermal ablation for colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC).

METHODS

One hundred sixty-one CRLM nodules in 101 patients and 122 HCC nodules in 97 patients were treated with thermal ablation. Complications and local efficacy were retrospectively compared.

RESULTS

Major complications were observed in two (2.0%) patients in the CRLM group and one (1.0%) in the HCC group (p = 1.000). The complete ablation (CA) rate of lesions ≤ 3 cm was lower in the CRLM group than in the HCC group (p = 0.018). After a mean follow-up period of 21.1 ± 20.7 months in the CRLM group and 22.1 ± 17.6 months in the HCC group, the local tumour progression (LTP) rate of lesions > 3 cm was higher in the CRLM group than in the HCC group (p = 0.036). The multivariate analysis revealed that only safety margin (≤ 0.5 cm/> 0.5 cm) was a significant predictor of LTP in both CRLM and HCC.

CONCLUSIONS

To achieve better local tumour control, thermal ablation should be more aggressive for CRLM than for HCC, especially for large tumours in clinical.

Local Ablation for Solid Tumor Liver Metastases: Techniques and Treatment Efficacy

BACKGROUND

Treatment options for liver metastases from solid tumors, such as colon cancer, breast cancer, neuroendocrine tumors, and sarcomas, have expanded in recent years and now include nonresection methods.

METHODS

The literature focused on the treatment of liver metastases was reviewed for technique, perioperative, and long-term outcomes specifically related to local ablation techniques for liver metastases.

RESULTS

Ablation modalities have become popular as therapies for patients who are not appropriate candidates for surgical resection. Use of these techniques, alone or in combination with other liver-directed therapies (and often systemic therapy), has extended the rate of survival for patients with liver metastases and, at times, offers nearly equivalent disease-free survival rates to surgical resection.

CONCLUSIONS

Although surgical resection remains the optimal treatment for liver metastasis, local options, including microwave ablation and radiofrequency ablation, can offer similar long-term local control in appropriately selected patients.

The role of radiofrequency ablation for treatment of metachronous isolated hepatic metastasis from colorectal cancer

We investigated recurrence pattern and oncologic outcomes after treatment of metachronous isolated liver metastases from colorectal cancer according to treatment modality.We retrospectively analyzed 123 patients treated with hepatic resection and 82 patients treated with radiofrequency ablation (RFA) for metachronous isolated hepatic metastasis from colorectal cancer (HMCRC). We compared clinicopathological data, recurrence pattern, and recurrence-free survival (RFS) rates after the treatment of hepatic metastasis between patients treated with RFA and resection.The patients in the 2 groups were similar in gender, location of primary tumor, disease-free interval to hepatic metastasis, pathologic stage of primary tumor, and number of hepatic metastasis. The age was older in RFA group but it was not statistically different. The mean diameter of the largest hepatic mass was greater in the resection group than in the RFA group (3.1 vs 1.9 cm, P < 0.001). Chemotherapy after the treatment of hepatic metastasis was more commonly given in hepatic resection group (76.4% vs 62.2%, P = 0.04). Recurrence after the treatment of hepatic metastasis was not significantly different between the 2 groups (54.5% vs 65.9% in the resection and RFA groups). However, intrahepatic recurrence without extra-hepatic metastases was more common in the RFA group than in the resection group (47.5% vs 12.1%, P < 0.001). The RFS rate after the treatment of hepatic metastasis was significantly higher in resection group (48.6% vs 33.7%, P = 0.015). The size and number of hepatic metastasis, primary tumor stage, disease-free interval to hepatic metastasis, and the modality of treatment (RFA vs resection) for hepatic metastasis were confirmed as associated factors with re-recurrence after the treatment of hepatic metastasis. Among patients with solitary hepatic metastases of ≤3 cm, marginal recurrence was higher in the RFA group (3% vs 17.2%) and re-RFA was performed to achieve comparable recurrence rate (3% vs 5.2%, P = 0.662), the RFS rate was not different between the resection and RFA group (52.4% vs 53.4%, P = 0.491).Surgical resection for HMCRC showed higher RFS. However, the RFS rate in patients with a solitary hepatic metastasis of ≤3 cm was similar between the resection and RFA groups.

Radiofrequency ablation vs. hepatic resection for resectable colorectal liver metastases

The treatments of resectable colorectal liver metastases (CRLM) are controversial. This study aimed to evaluate the relative efficacy and safety of hepatic resection (HR) and radiofrequency ablation (RFA) for treating resectable CRLM. Between January 2004 and May 2010, the enrolled patients were given hepatic resection (HR group; n=32) or percutaneous RFA (RFA group; n=21) as a first-line treatment for CRLM. All the tumors had a maximum diameter of 3.5 cm and all patients had five or less tumors. The patient background, tumor characteristics, cumulative survival rate and recurrence-free survival rate were assessed in both groups. There were significantly more patients with comorbidities in the RFA group than those in the HR group (17 in RFA group vs. 10 in HR group; P<0.000). The mean maximum tumor diameter in the HR group and RFA group was 2.25±0.68 and 1.89±0.62 cm (P=0.054), and the mean number of tumors was 2.28±1.05 and 2.38±1.12 (P=0.744), respectively. The 1-, 3- and 5-year cumulative survival rates in the HR group were 87.5%, 53.1% and 31.3%, respectively, and those in the RFA group were 85.7%, 38.1% and 14.2%, respectively with the differences being not significant between the two groups (P=0.062). The 1-, 3- and 5-year recurrence-free survival rates in the HR group were 90.6%, 56.3% and 28.1%, respectively, and those in the RFA group were 76.1%, 23.8% and 4.8%, respectively, with the differences being significant between the two groups (P=0.036). In conclusion, as HR has greater efficacy than RFA in the treatment of resectable CRLM, we recommend it as the first option for this malignancy.

Laparoscopy-Guided Transthoracic Transdiaphragmatic Radiofrequency Ablation for Hepatic Tumors Located Beneath the Diaphragm

BACKGROUND

It is often difficult to perform percutaneous radiofrequency ablation (RFA) for hepatic tumors beneath the diaphragm. Diaphragmatic thermal damage is one of the fatal late complications of percutaneous transdiaphragmatic RFA. Our experience with laparoscopic transthoracic transdiaphragmatic intraoperative RFA (LTTI-RFA) for hepatic tumors beneath the diaphragm is reported.

METHODS

Ten patients who underwent LTTI-RFA from 2009 to 2012 were evaluated. Two cases had concomitant partial hepatectomy, and one underwent RFA for two tumors at the same time. The diagnosis was hepatocellular carcinoma in eight cases and metastatic hepatic tumors in two cases. Nine of eleven tumors were located at segments 7 and 8. Nine tumors were less than 20 mm in diameter. The patients were placed in the half left lateral decubitus position with single-lumen tube intubation. After placement of four abdominal ports, a 12-mm port was inserted in the fourth or fifth intercostal space into the diaphragm. The tumor was ablated by an RFA needle through the port. The routine follow-up consisted of laboratory tests and abdominal imaging every 3-6 months.

RESULTS

The median operation time for only one tumor was 137 minutes (range, 105-187 minutes). The median number of times for ablation was three. Severe postoperative complications (>Clavien-Dindo IIIa) were observed in one case (right upper limb paralysis). The median follow-up period was 35 months (range, 11-43 months). There was no local tumor progression. Recurrent hepatic tumor appearance occurred in other parts of the liver in 6 of the 11 patients.

CONCLUSIONS

Laparoscopic transthoracic transdiaphragmatic RFA is an acceptable procedure with a low rate of local recurrence.

The state of regional therapy in the management of metastatic colorectal cancer to the liver

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality in the United States. Most colorectal cancer patients die from advanced disease, and two-thirds of CRC deaths are due to liver metastases. Liver resection provides the best curative option for patients with colorectal liver metastases (CRLM), yet only 20% of those patients are eligible for liver metastases resection for curative intent. Loco-regional treatment of CRLM may provide additional benefits in terms of down-staging for resection and prolonged hepatic disease control. This review focusses on hepatic arterial infusion, radioembolization and chemoembolization.

Thermal ablation of colorectal liver metastases: a position paper by an international panel of ablation experts, The Interventional Oncology Sans Frontières meeting 2013

Objectives

Previous attempts at meta-analysis and systematic review have not provided clear recommendations for the clinical application of thermal ablation in metastatic colorectal cancer. Many authors believe that the probability of gathering randomised controlled trial (RCT) data is low. Our aim is to provide a consensus document making recommendations on the appropriate application of thermal ablation in patients with colorectal liver metastases.

Methods

This consensus paper was discussed by an expert panel at The Interventional Oncology Sans Frontières 2013. A literature review was presented. Tumour characteristics, ablation technique and different clinical applications were considered and the level of consensus was documented.

Results

Specific recommendations are made with regard to metastasis size, number, and location and ablation technique. Mean 31 % 5-year survival post-ablation in selected patients has resulted in acceptance of this therapy for those with technically inoperable but limited liver disease and those with limited liver reserve or co-morbidities that render them inoperable.

Conclusions

In the absence of RCT data, it is our aim that this consensus document will facilitate judicious selection of the patients most likely to benefit from thermal ablation and provide a unified interventional oncological perspective for the use of this technology.

Key Points

• Best results require due consideration of tumour size, number, volume and location.

• Ablation technology, imaging guidance and intra-procedural imaging assessment must be optimised.

• Accepted applications include inoperable disease due to tumour distribution or inadequate liver reserve.

• Other current indications include concurrent co-morbidity, patient choice and the test-of-time approach.

• Future applications may include resectable disease, e.g. for small solitary tumours.

Non-operative therapies for colorectal liver metastases

Locoregional therapies for colorectal liver metastases complement systemic therapy by providing an opportunity for local control of hepatic spread. The armamentarium for liver-directed therapy includes ablative therapies, embolization, and stereotactic body radiation therapy. At this time, prospective studies comparing these modalities are limited and decision-making relies on a multidisciplinary approach for optimal patient management. Herein, we describe multiple therapeutic non-surgical procedures and an overview of the results of these treatments.

Radiofrequency ablation for neuroendocrine liver metastases: a systematic review

To determine the efficacy of radiofrequency (RF) ablation in neuroendocrine tumor (NET) liver metastases. A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight studies were included (N = 301). Twenty-six percent of RF ablation procedures were percutaneous (n = 156), with the remainder conducted at surgery. Forty-eight percent of patients had a concomitant liver resection. Fifty-four percent of patients presented with symptoms, with 92% reporting symptom improvement following RF ablation (alone or in combination with surgery). The median duration of symptom improvement was 14-27 months. However, recurrence was common (63%-87%). RF ablation can provide symptomatic relief in NET liver metastases alone or in combination with surgery.

Ablative technologies for hepatocellular, cholangiocarcinoma, and metastatic colorectal cancer of the liver

A wide array of ablation technologies, in addition to the progressive sophistication of imaging technologies and percutaneous, laparoscopic, and open surgical techniques, have allowed us to expand treatment options for patients with liver tumors. In this article, technical considerations of chemical and thermal ablations and their application in hepatic oncology are reviewed.

Intraductal radiofrequency ablation for management of malignant biliary obstruction

Self-expandable metal stents (SEMS) are the current standard of care for the palliative management of malignant biliary strictures. Recently, endoscopic ablative techniques with direct affect to local tumor have been developed to improve SEMS patency. Several reports have demonstrated the technical feasibility and safety of intraductal radiofrequency ablation (RFA), by both endoscopic and percutaneous approaches, in palliation of malignant strictures of the bile duct. Intraductal RFA has also been used in the treatment of occlusion of both covered and uncovered SEMS occlusion from tumor ingrowth or overgrowth. This article provides a comprehensive review of intraductal RFA in the management of malignant biliary obstruction.

Laparoscopic-assisted ablation of hepatic tumors: a review

Thermal ablation of hepatic tumors has been an evolving field over the last two decades. It is used in the treatment of both primary and metastatic neoplasms, and with evolutions in the technology, there has been an increasing interest in treating lesions where hepatic resection is not an option. Laparoscopic or minimally invasive surgical procedures have also advanced during this same time period, and the interface of these tools has been associated with the genesis of a new approach for treating hepatic lesions which are located in difficult to reach locations or found immediately adjacent to other intra-abdominal organs. This review summarizes the published literature focusing on the treatment of primary and metastatic neoplasms located in the liver, including a review of outcomes.

Surgical resection of hepatic metastasis from gastric cancer: a review and new recommendation in the Japanese gastric cancer treatment guidelines

Liver metastases from gastric cancer are rarely indicated for surgery because they are often diagnosed as multiple nodules occupying both lobes and coexist with extra hepatic disease. A literature search identified no clinical trials on hepatectomy for this disease; only retrospective studies of a relatively small number of cases collected over more than a decade, mostly from a single institution, were found. Five-year survival rates from these reports ranged from 0 % to 37 %, and long-term survivors were observed among carefully selected case series. The most commonly reported prognostic factor was the number of metastatic nodules, and patients with a solitary metastasis tended to have superior outcome. Patients diagnosed to have a small number of metastatic nodules by modern imaging tools could be indicated for surgery. Because both intrahepatic and extrahepatic recurrences are common,patients are likely to benefit from perioperative adjuvant chemotherapy, although it is not possible at this time to specify which regimen is the most appropriate

Percutaneous radiofrequency ablation (RFA) or robotic radiosurgery (RRS) for salvage treatment of colorectal liver metastases

BACKGROUND

Stereotactic radiation therapy is an evolving modality to treat otherwise unresectable liver metastases. In this analysis, two local therapies: 1) single session robotic radiosurgery (RRS) and 2) percutaneous radiofrequency ablation (RFA) were compared in a total of 60 heavily pretreated colorectal cancer patients.

METHODS

Thirty patients with a total of 35 colorectal liver metastases not qualifying for surgery that were treated in curative intent with RRS were prospectively followed. To compare efficacy of both treatment modalities, patients treated with RFA during the same period of time were matched according to number and size of the treated lesions. Local tumor control, local disease free survival (DFS), and freedom from distant recurrence (FFDR) were analyzed for efficacy. Treatment-related side effects were recorded for comparison.

RESULTS

The median diameter of the treated lesions was 33 mm (7-53 mm). Baseline characteristics did not differ significantly between the groups. One- and two-year local control rates showed no significant difference but favored RRS (85% vs. 65% and 80% vs. 61%, respectively). A significantly longer local DFS of patients treated with RRS compared to RFA (34.4 months vs. 6.0 months; p < 0.001) was found. Both, median FFDR (11.4 months for RRS vs. 7.1 months for RFA p = 0.25) and the recurrence rate (67% for RRS and 63% for RFA, p > 0.99) were comparable.

CONCLUSION

Single session RRS is a safe and effective method to treat colorectal liver metastases. In this analysis, a trend towards longer DFS was seen in patients treated with RRS when compared to RFA.