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

Stereotactic body radiotherapy for liver metastases

The role for local ablative therapies in the management paradigm of oligometastatic liver disease is increasing. The evidence base supporting the use of stereotactic body radiotherapy for liver metastases has expanded rapidly over the past decade, showing high rates of local control with low associated toxicity. This review summarises the evidence base to date, discussing optimal patient selection, challenges involved with treatment delivery and optimal dose and fractionation. The reported toxicity associated with liver stereotactic body radiotherapy is presented, together with possible pitfalls in interpreting the response to treatment using standard imaging modalities. Finally, potential avenues for future research in this area are highlighted.

Analysis of tissue changes, measurement system effects, and motion artifacts in echo decorrelation imaging

Echo decorrelation imaging, a method for mapping ablation-induced ultrasound echo changes, is analyzed. Local echo decorrelation is shown to approximate the decoherence spectrum of tissue reflectivity. Effects of the ultrasound measurement system, echo signal windowing, electronic noise, and tissue motion on echo decorrelation images are determined theoretically, leading to a method for reduction of motion and noise artifacts. Theoretical analysis is validated by simulations and experiments. Simulated decoherence of the scattering medium was recovered with root-mean-square error less than 10% with accuracy dependent on the correlation window size. Motion-induced decorrelation measured in an ex vivo pubovisceral muscle model showed similar trends to theoretical motion-induced decorrelation for a 2.1 MHz curvilinear array with decorrelation approaching unity for 3-4 mm elevational displacement or 1-1.6 mm range displacement. For in vivo imaging of porcine liver by a 7 MHz linear array, theoretical decorrelation computed using image-based motion estimates correlated significantly with measured decorrelation (r = 0.931, N = 10). Echo decorrelation artifacts incurred during in vivo radiofrequency ablation in the same porcine liver were effectively compensated based on the theoretical echo decorrelation model and measured pre-treatment decorrelation. These results demonstrate the potential of echo decorrelation imaging for quantification of heat-induced changes to the scattering tissue medium during thermal ablation.

Surgical Referral for Colorectal Liver Metastases: A Population-Based Survey

BACKGROUND

Surgical resection is underutilized for patients with colorectal liver metastases (CLM). Although the causes of underutilization are poorly understood, provider attitudes towards surgical referral may be contributory. We sought to understand medical oncologists' perspectives on referral for CLM.

METHODS

Medical oncologists who treat colorectal cancer in the US state of Michigan were surveyed. We characterized respondents' attitudes regarding clinical and tumor-related contraindications to liver resection for CLM, as well as referral and treatment preferences using case-based scenarios. We then evaluated practice characteristics and treatment preferences between physicians.

RESULTS

A total of 112 eligible responses were received (46 % response rate). Nearly 40 % of respondents reported having no liver surgeons in their practice area. Commonly perceived contraindications to liver resection included extrahepatic disease (80.3 %), poor performance status (77.7 %), the presence of >4 metastases (62.5 %), bilobar metastases (43.8 %), and metastasis size >5 cm (40.2 %). Compared with high-referring physicians, low-referring physicians were just as likely to refer a patient with very low recurrence risk (89.3 vs. 98.3 %; p = 0.099), but much less likely to refer a patient with moderate risk (0 vs. 82.8 %; p < 0.001). High-referring physicians were more likely to consider resection for scenarios consistent with higher recurrence risk (31.0 vs. 10.7 %; p = 0.05).

CONCLUSIONS

We found wide variation in surgical referral patterns for CLM. Many felt that bilobar disease and tumor size were contraindications to liver-directed therapy despite a lack of supporting data. These findings suggest an urgent need to increase dissemination of evidence and guidance regarding management for CLM, perhaps through increased specialist participation in tumor boards.

Prognostic value of circulating tumour cells for early recurrence after resection of colorectal liver metastases

BACKGROUND

Despite good outcomes for many, a substantial group of patients undergoing metastasectomy for isolated liver metastases from colorectal cancer (CRC) experience early recurrence. We have investigated whether circulating tumour cell (CTC) detection can identify patients developing disease recurrence within 1 year after liver metastasectomy.

METHODS

In CRC patients undergoing liver metastasectomy, 30 ml peripheral blood was withdrawn preoperatively. CTCs were detected by the CellSearch system after a density-gradient-based enrichment step.

RESULTS

One hundred and seventy-three samples from 151 individual patients were analysed. In 75 samples (43%), CTCs were detected, 16% had ⩾3 CTCs/7.5 ml of blood. Eighty-two patients (47%) experienced early disease recurrence (<1 year). The 1-year recurrence rate between patients with or without detectable CTCs were similar (47% vs 48%) or with a low or high CTC count (<3 or ⩾3 CTCs/7.5 ml of blood) (50% vs 47%). Also disease-free and overall survival were similar between patients with or without CTCs.

CONCLUSIONS

The presence of CTCs in preoperative peripheral blood samples does not identify patients at risk for early disease recurrence after curative resection of colorectal liver metastases. Other parameters are needed to better identify patients at high risk to relapse after liver metastasectomy for CRC.

RFA-cut: Semi-automatic segmentation of radiofrequency ablation zones with and without needles via optimal s-t-cuts

In this contribution, we present a semi-automatic segmentation algorithm for radiofrequency ablation (RFA) zones via optimal s-t-cuts. Our interactive graph-based approach builds upon a polyhedron to construct the graph and was specifically designed for computed tomography (CT) acquisitions from patients that had RFA treatments of Hepatocellular Carcinomas (HCC). For evaluation, we used twelve post-interventional CT datasets from the clinical routine and as evaluation metric we utilized the Dice Similarity Coefficient (DSC), which is commonly accepted for judging computer aided medical segmentation tasks. Compared with pure manual slice-by-slice expert segmentations from interventional radiologists, we were able to achieve a DSC of about eighty percent, which is sufficient for our clinical needs. Moreover, our approach was able to handle images containing (DSC=75.9%) and not containing (78.1%) the RFA needles still in place. Additionally, we found no statistically significant difference (p<;0.423) between the segmentation results of the subgroups for a Mann-Whitney test. Finally, to the best of our knowledge, this is the first time a segmentation approach for CT scans including the RFA needles is reported and we show why another state-of-the-art segmentation method fails for these cases. Intraoperative scans including an RFA probe are very critical in the clinical practice and need a very careful segmentation and inspection to avoid under-treatment, which may result in tumor recurrence (up to 40%). If the decision can be made during the intervention, an additional ablation can be performed without removing the entire needle. This decreases the patient stress and associated risks and costs of a separate intervention at a later date. Ultimately, the segmented ablation zone containing the RFA needle can be used for a precise ablation simulation as the real needle position is known.

Outcomes of microwave ablation for colorectal cancer liver metastases: a single center experience

BACKGROUND AND OBJECTIVES

Surgical management of colorectal cancer liver metastases continues to evolve to optimize oncologic outcomes while maximizing parenchymal preservation. Long-term data after intraoperative microwave ablation are limited. This study investigates outcomes and patterns of recurrence in patients who underwent intraoperative microwave ablation.

METHODS

A retrospective analysis of 33 patients who underwent intraoperative microwave ablation of colorectal cancer liver metastases from 2009 to 2013 at our institution was performed. Perioperative and long-term data were reviewed to determine outcomes and patterns of recurrence.

RESULTS

A total of 49 tumors were treated, ranging 0.5-5.5 cm in size. Median Clavien-Dindo classification was one. Median follow-up was 531 days, with 13 (39.4%) patients presenting with a recurrence. Median time to first recurrence was 364 days. In those patients, 1 (7.8%) presented with an isolated local recurrence in the liver. Only 1 of 7 ablated tumors greater than 3 cm recurred (14.3%). Overall survival was 35.2% at 4 years, with a 19.3% disease-free survival at 3.5 years. No perioperative variables predicted systemic or local recurrence.

CONCLUSION

Intraoperative microwave ablation is a safe and effective modality for use in the treatment of colorectal cancer liver metastases in tumors as large as 5.5 cm in size.

The power of genes: a case of unusually severe systemic toxicity after localized hepatic chemoembolization with irinotecan-eluted microspheres for metastatic colon cancer

OBJECTIVE

To report a case of systemic irinotecan toxicity following regional transarterial chemoembolization with drug-eluting beads loaded with irinotecan (DEBIRI-TACE) in a patient later found to have a homozygous mutation for UGT1A1*28.

CASE SUMMARY

An 80-year-old woman presented with a cecal colon cancer with synchronous metastases to the liver. After resection of the primary tumor, the patient underwent DEBIRI-TACE with 100 mg of irinotecan to treat the residual disease in the liver. A week after this procedure, the patient developed grade 4 neutropenia, and later, alopecia. Eventually, it was found that the patient had a mutation of UDP glucuronosyltransferase 1 family polypeptide A1 (UGT1A1), which provided a reasonable explanation for the observed reaction.

DISCUSSION

The toxic effects of irinotecan are well understood. Patients with genetic polymorphisms of the genes encoding for the enzyme UGT1A1 may have increased incidence of irinotecan-associated toxicities because of decreased clearance of the active metabolite SN38 via the glucuronidation pathway. To date, there have been limited publications describing systemic adverse events following TACE or DEBIRI-TACE and, based on a thorough literature search, none following these procedures in patients with UGT1A1 polymorphisms. Based on the scoring results of the Naranjo algorithm (7), we are confident in attributing the observed reaction to the patient's genetic polymorphism.

CONCLUSION

Although genetic testing prior to the initiation of irinotecan therapy is not currently recommended, assessment of UGT1A1 polymorphism is warranted when severe adverse events typical of systemic therapy manifest following DEBIRI-TACE.

Comparative analysis of Laparoscopic versus open surgical radiofrequency ablation for malignant liver tumors

Backgrounds/Aims

This study aims to evaluate the comparative effectiveness of two surgical approaches on the treatment outcomes of radiofrequency ablation (RFA) for malignant liver tumors.

Methods

Fifty-seven patients with malignant liver tumors, hepatocellular carcinoma, cholangiocarcinoma and liver metastases, who were candidates for RFA, underwent laparoscopic or open surgical treatments.

Results

The patients' characteristics were comparable in the two groups that received open (n=33, 57.9%) and laparoscopic (n=24, 42.1%) surgical treatments. There were no statistically significant differences between the two groups in terms of recurrence rate (p=0.337) and overall survival (p=0.423). However, patients in the laparoscopic RFA group had significantly shorter hospital stay (14.1 vs. 5.9 days, p<0.05) and experienced fewer complications (Grade I: 62.5% vs. 26.3%, p=0.102).

Conclusions

Laparoscopic RFA can be performed for malignant liver tumors with lower morbidity rates, less invasiveness and lower expense compared to open surgical approach.

Does "conversion chemotherapy" really improve survival in metastatic colorectal cancer patients with liver-limited disease?

BACKGROUND

The clinical benefits of conversion chemotherapy followed by liver resection for initially unresectable colorectal liver metastases are still controversial. The criteria for unresectability vary from one team to another. To clarify this issue, we retrospectively assessed the survival and characteristics of metastatic colorectal cancer (mCRC) patients with liver-limited disease (LLD) who underwent conversion therapy.

METHOD

Our criteria for resectability depended on the size of the remnant liver volume (>30 %) and expected function after removal of all metastases. Between December 2007 and September 2011, a total of 115 patients were diagnosed as having mCRC with LLD and received chemotherapy. Among them, 47 had tumors that were initially diagnosed as resectable. They underwent hepatic resection after chemotherapy (resected group). Of the 67 tumors were initially diagnosed as unresectable, 12 became resectable after chemotherapy (conversion group), leaving 55 tumors that remained unresectable after chemotherapy (unresected group).

RESULTS

The median follow-up was 25.2 months. Hepatic resection was more invasive in the conversion group than in the resected group. Median disease-free survival was significantly higher in the resected group than in the conversion group (p = 0.013). Overall survival (OS) was also higher in the resected group, but the difference was not significant (p = 0.36). However, OS was significantly higher in the conversion group than in the unresected group (p = 0.034). Multivariate analysis of the resected and conversion groups showed that OS was significantly negatively influenced by abnormal carcinoembryonic antigen levels at surgery (p = 0.037) and a hospital stay >30 days (p = 0.009).

CONCLUSIONS

Our results showed that conversion chemotherapy could contribute to longer OS in mCRC patients with LLD.

Patterns of complications following intraoperative radiofrequency ablation for liver metastases

BACKGROUND

Intraoperative radiofrequency ablation (IRFA) is added to surgery to obtain hepatic clearance of liver metastases. Complications occurring in IRFA should differ from those associated with wedge or anatomic liver resection.

METHODS

Patients with liver metastases treated with IRFA from 2000 to 2010 were retrospectively analysed. Postoperative outcomes are reported according to the Clavien-Dindo system of classification.

RESULTS

A total of 151 patients underwent 173 procedures for 430 metastases. Of these, 97 procedures involved IRFA plus liver resection and 76 involved IRFA only. The median number of lesions treated by IRFA was two (range: 1-11). A total of 123 (71.1%) procedures were carried out in patients who had received preoperative chemotherapy. The mortality rate was 1.2%. Thirty (39.5%) IRFA-only patients and 45 (46.4%) IRFA-plus-resection patients presented complications. Immediate complications (n = 4) were associated with IRFA plus resection. American Society of Anesthesiologists (ASA) class, previous abdominal surgery or hepatic resection, body mass index, number of IRFA procedures, portal pedicle clamping, total vascular exclusion and preoperative chemotherapy were not associated with a greater number of complications of Grade III or higher severity. Length of surgery >4 h [odds ratio (OR) 2.67, 95% confidence interval (CI) 1.1-6.3; P < 0.05] and an associated contaminating procedure (OR 3.72, 95% CI 1.53-9.06; P < 0.005) led to a greater frequency of complications of Grade III or higher.

CONCLUSIONS

Mortality and morbidity after IRFA, with or without resection, are low. Nevertheless, long interventions and concurrent bowel operations increase the risk for septic complications.

Near-infrared light-sensitive liposomes for the enhanced photothermal tumor treatment by the combination with chemotherapy

PURPOSE

To develop a near-infrared (NIR) light-sensitive liposome, which contains hollow gold nanospheres (HAuNS) and doxorubicin (DOX), and evaluate their potential utility for enhancing antitumor activity and controlling drug release.

METHODS

The liposomes (DOX&HAuNS-TSL) were designed based on a thermal sensitive liposome (TSL) formulation, and hydrophobically modified HAuNS were attached onto the membrane of the liposomes. The behavior of DOX release from the liposomes was investigated by the dialysis, diffusion in agarose gel and cellular uptake of the drug. The biodistribution of DOX&HAuNS-TSL was assessed by i.v. injection in tumor-bearing nude mice. Antitumor efficacy was evaluated both histologically using excised tissue and intuitively by measuring the tumor size and weight.

RESULTS

Rapid and repetitive DOX release from the liposomes (DOX&HAuNS-TSL), could be readily achieved upon NIR laser irradiation. The treatment of tumor cells with DOX&HAuNS-TSL followed by NIR laser irradiation showed significantly greater cytotoxicity than the treatment with DOX&HAuNS-TSL alone, DOX-TSL alone (chemotherapy alone) and HAuNS-TSL plus NIR laser irradiation (Photothermal ablation, PTA, alone). In vivo antitumor study indicated that the combination of simultaneous photothermal and chemotherapeutic effect mediated by DOX&HAuNS-TSL plus NIR laser presented a significantly higher antitumor efficacy than the PTA alone mediated by HAuNS-TSL plus NIR laser irradiation.

CONCLUSIONS

Our study could be as the valuable reference and direction for the clinical application of PTA in tumor therapy.

Long-term outcomes following microwave ablation for liver malignancies

BACKGROUND

Microwave ablation has emerged as a promising treatment for liver malignancies, but there are scant long-term follow-up data. This study evaluated long-term outcomes, with a comparison of 915-MHz and 2.4-GHz ablation systems.

METHODS

This was a retrospective review of patients with malignant liver tumours undergoing operative microwave ablation with or without liver resection between 2008 and 2013. Regional or systemic (neo)adjuvant therapy was given selectively. Local recurrence was analysed using competing-risk methods with clustering, and overall survival was determined from Kaplan-Meier curves.

RESULTS

A total of 176 patients with 416 tumours were analysed. Colorectal liver metastases (CRLM) comprised 81.0 per cent of tumours, hepatocellular carcinoma 8.4 per cent, primary biliary cancer 1.7 per cent and non-CRLM 8.9 per cent. Median follow-up was 20.5 months. Local recurrence developed after treatment of 33 tumours (7.9 per cent) in 31 patients (17.6 per cent). Recurrence rates increased with tumour size, and were 1.0, 9.3 and 33 per cent for lesions smaller than 1 cm, 1-3 cm and larger than 3 cm respectively. On univariable analysis, the local recurrence rate was higher after ablation of larger tumours (hazard ratio (HR) 2.05 per cm; P < 0.001), in those with a perivascular (HR 3.71; P = 0.001) or subcapsular (HR 2.71; P = 0.008) location, or biliary or non-CRLM histology (HR 2.47; P = 0.036), and with use of the 2.4-GHz ablation system (HR 3.79; P = 0.001). Tumour size (P < 0.001) and perivascular position (P = 0.045) remained significant independent predictors on multivariable analysis. Regional chemotherapy was associated with decreased local recurrence (HR 0.49; P = 0.049). Overall survival at 4 years was 58.3 per cent for CRLM and 79.4 per cent for other pathology (P = 0.360).

CONCLUSION

Microwave ablation of liver malignancies, either combined or not combined with liver resection, and selective regional and systemic therapy resulted in good long-term survival. Local recurrence rates were low after treatment of tumours smaller than 3 cm in diameter, and those remote from vessels.

Integrating systemic and surgical approaches to treating metastatic colorectal cancer

Multiple new treatment options for metastatic colorectal cancer have been developed over the past 2 decades, including conventional chemotherapy and agents directed against vascular endothelial growth factor and epidermal growth factor receptor. Combination regimens, integrated with surgical approaches, have led to an increase in median survival, and a minority of patients with resectable disease can survive for years. Clinical decision-making therefore requires a strategic, biomarker-based multidisciplinary approach to maximize life expectancy and quality of life. This review describes systemic approaches to the treatment of patients with metastatic colorectal cancer, including integration with liver resection, other liver-directed therapies, and primary resection.

Incremental value of liver MR imaging in patients with potentially curable colorectal hepatic metastasis detected at CT: a prospective comparison of diffusion-weighted imaging, gadoxetic acid-enhanced MR imaging, and a combination of both MR techniques

PURPOSE

To prospectively compare diagnostic performance of diffusion-weighted (DW) imaging, gadoxetic acid-enhanced magnetic resonance (MR) imaging, both techniques combined (combined MR imaging), and computed tomography (CT) for detecting colorectal hepatic metastases and evaluate incremental value of MR for patients with potentially curable colorectal hepatic metastases detected with CT.

MATERIALS AND METHODS

In this institutional review board-approved prospective study, with informed consent, 51 patients (39 men, 12 women; mean age, 62 years) with potentially resectable hepatic metastases detected with CT underwent liver MR, including DW imaging and gadoxetic acid-enhanced MR. Two independent readers reviewed DW, gadoxetic acid-enhanced, combined MR, and CT image sets to detect hepatic metastases. The figure-of-merit (FOM) value representing overall diagnostic performance, sensitivity, and positive predictive value (PPV) for each image set were analyzed by using free-response receiver operating characteristic analysis and generalized estimating equations.

RESULTS

There were 104 hepatic metastases in 47 patients. The pooled FOM values, sensitivities, and PPVs of combined MR (FOM value, 0.93; sensitivity, 98%; and PPV, 88%) and gadoxetic acid-enhanced MR (FOM value, 0.92; sensitivity, 95%; and PPV, 90%) were significantly higher than those of CT (FOM value, 0.82; sensitivity, 85%; and PPV, 73%) (P < .006). The pooled FOM value and sensitivity of combined MR (FOM value, 0.92; sensitivity, 95%) was also significantly higher than that of DW imaging (FOM value, 0.82; sensitivity, 79%) for metastases (≤1-cm diameter) (P ≤ .003). DW imaging showed significantly higher pooled sensitivity (79%) and PPV (60%) than CT (sensitivity, 50%; PPV, 33%) for the metastases (≤1-cm diameter) (P ≤ .004). In 47 patients with hepatic metastases, combined MR depicted more metastases than CT in 10 and 14 patients, respectively, according to both readers.

CONCLUSION

Gadoxetic acid-enhanced MR and combined MR are more accurate than CT in detecting colorectal hepatic metastases, have an incremental value when added to CT alone for detecting additional metastases, and can be routinely performed in patients with potentially curable hepatic metastases detected with CT.

Colorectal cancer with liver metastases: Neoadjuvant chemotherapy, surgical resection first or palliation alone?

Colorectal cancer (CRC) is one of the commonest cancers with 1.2 million new cases diagnosed each year in the world. It remains the fourth most common cause of cancer-related mortality in the world and accounts for > 600000 cancer-related deaths each year. There have been significant advances in treatment of metastatic CRC in last decade or so, due to availability of new active targeted agents and more aggressive approach towards the management of CRC, particularly with liver-only-metastases; however, these drugs work best when combined with conventional chemotherapy agents. Despite these advances, there is a lack of biomarkers to inform us about the accurate management of the patients with metastatic CRC. It is therefore imperative to carefully select the patients with comprehensive multi-disciplinary team input in order to optimise the management of these patients. In this review we will discuss various treatment options available in management of colorectal liver metastases with potential guidance on how and when to choose these options along with consideration on future directions in management of this disease.

Systematic evaluation of percutaneous radiofrequency ablation versus percutaneous ethanol injection for the treatment of small hepatocellular carcinoma: a meta-analysis

BACKGROUND

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) have been used for patients with hepatocellular carcinoma (HCC). However, which therapy is superior remains to be further elucidated. We aimed to conduct a systematic review to assess survival and local tumor recurrence rate with RFA compared with PEI therapy for HCC.

METHODS

We conducted systematic review and meta-analysis of randomized controlled trials (RCTs) published up to 2014 in PubMed, MEDLINE, EMBASE, EBSCO, Springer, Ovid and the Cochrane library. Only RCTs that evaluated survival rate and occurrence of HCC between RFA and PEI therapy were included. The OR (odds ratio) with a 95% confidence interval (CI) was calculated by the Revman 5.0 software.

RESULTS

A total of six studies including 983 HCC patients were eligible for this analysis. The survival rate showed a significant benefit under RFA therapy over PEI at 1-year (P = 0.02, OR = 1.88, 95% CI: 1.09 to 3.22), 2-years (P = 0.0003, OR = 2.06, 95% CI: 1.39 to 3.05) and 3-years (P = 0.0007, OR = 1.68, 95% CI: 1.25 to 2.27). Likewise, RFA achieved significantly lower rates of local tumor recurrence over PEI at 1-year (P = 0.002, OR = 0.43, 95% CI: 0.26 to 0.73), 2-year (P = 0.03, OR = 0.33, 95% CI: 0.12 to 0.88) and 3-year (P = 0.003, OR = 0.61, 95% CI: 0.43 to 0.84).

CONCLUSIONS

The current evidence suggests that RFA is superior to PEI in better survival and local disease control for small HCCs <5 cm in diameter and that RFA is worthy of promotion in clinical applications.

[18F]Fluorodeoxyglucose PET for Interventional Oncology in Liver Malignancy

[(18)F]Fluorodeoxyglucose (FDG) PET is a functional imaging tool that provides metabolic information, which has the potential to detect a lesion before it becomes anatomically apparent. This ability constitutes a strong argument for using FDG-PET/computed tomography (CT) in the management of oncology patients. Many studies have investigated the accuracy of FDG-PET or FDG-PET/CT for these purposes, but with small sample sizes based on retrospective cohorts. This article provides an overview of the role of FDG-PET or FDG-PET/CT in patients with liver malignancies treated by means of surgical resection, ablative therapy, chemoembolization, radioembolization, and brachytherapy, all being liver-directed oncologic interventions.

The use of PET-MRI in the follow-up after radiofrequency- and microwave ablation of colorectal liver metastases

Background

Thermal ablation of colorectal liver metastases (CRLM) may result in local progression, which generally appear within a year of treatment. As the timely diagnosis of this progression allows potentially curative local treatment, an optimal follow-up imaging strategy is essential. PET-MRI is a one potential imaging modality, combining the advantages of PET and MRI. The aim of this study is evaluate fluorine-18 deoxyglucose positron emission tomography (FDG) PET-MRI as a modality for detection of local tumor progression during the first year following thermal ablation, as compared to the current standard, FDG PET-CT. The ability of FDG PET-MRI to detect new intrahepatic lesions, and the extent to which FDG PET-MRI alters clinical management, inter-observer variability and patient preference will also be included as secondary outcomes.

Methods/Design

Twenty patients undergoing treatment with radiofrequency or microwave ablation for (recurrent) CRLM will be included in this prospective trial. During the first year of follow-up, patients will be scanned at the VU University Medical Center at 3-monthly intervals using a 4-phase liver CT, FDG PET-CT and FDG PET-MRI. Patients treated with chemotherapy <6 weeks prior to scanning or with a contra-indication for MRI will be excluded. MRI will be performed using both whole body imaging (mDixon) and dedicated liver sequences, including diffusion-weighted imaging, T1 in-phase and opposed-phase, T2 and dynamic contrast-enhanced imaging. The results of all modalities will be scored by 4 individual reviewers and inter-observer agreement will be determined. The reference standard will be histology or clinical follow-up. A questionnaire regarding patients’ experience with both modalities will also be completed at the end of the follow-up year.

Discussion

Improved treatment options for local site recurrences following CRLM ablation mean that accurate post-ablation staging is becoming increasingly important. The combination of the sensitivity of MRI as a detection method for small intrahepatic lesions with the ability of FDG PET to visualize enhanced metabolism at the ablation site suggests that FDG PET-MRI could potentially improve the accuracy of (early) detection of progressive disease, and thus allow swifter and more effective decision-making regarding appropriate treatment.

Trial registration

Trial registration number: NCT01895673

Colorectal hepatic metastasis: Evolving therapies

The approach for colorectal hepatic metastasis has advanced tremendously over the past decade. Multidrug chemotherapy regimens have been successfully introduced with improved outcomes. Concurrently, adjunct multimodal therapies have improved survival rates, and increased the number of patients eligible for curative liver resection. Herein, we described major advancements of surgical and oncologic management of such lesions, thereby discussing modern chemotherapeutic regimens, adjunct therapies and surgical aspects of liver resection.

Understanding the current status of image-guided ablation for metastatic colorectal disease

Colorectal metastases to the liver are increasingly being detected and accurately characterized at an earlier stage and even at the subcentimeter level. The oncological case for surgical resection of this disease is widely accepted. The advent of smaller volume disease has encouraged the development of in situ ablative technologies over the last two decades and the oncological efficacy of these procedures has continued to improve through stepwise developments in ablation devices and image guidance. This article provides an overview of these techniques, currently available and future technologies, and the imaging findings encountered. It also sets out the current position image-guided ablation merits alongside chemotherapy and surgical resection. In selected cases ablation for colorectal metastases can produce oncological outcomes equivalent to surgery and critically with less morbidity in an increasingly older patient population. We examine whether with careful patient selection, optimal technology, meticulous technique, and diligent follow-up, consistently reproducible high quality outcomes will be achieved in the next few years.

Selection criteria for radiofrequency ablation for colorectal liver metastases in the era of effective systemic therapy: a clinical score based proposal

Background

At present, there are no widely accepted criteria for the use of radiofrequency ablation (RFA) for the treatment of colorectal liver metastases (CLM) in the context of effective modern-agent therapies. We aimed to define selection criteria for patients with liver-limited CLM who may benefit from adding RFA to systemic therapy with respect to long-term disease control.

Methods

Between 2002 and 2007, 88 consecutive patients received RFA for liver-only CLM during partial remission (PR), stable disease (SD), or progressive disease (PD) after systemic therapy. At a median follow-up of 8.2 years (range 5.2-11.1 years), clinical data were correlated to overall survival (OS) and recurrence-free survival (RFS).

Results

Poor OS and RFS correlated significantly with PD to systemic therapy before RFA (HR 5.46; p < 0.0001; and HR 6.46; p < 0.0001), number of ≥4 CLM (HR 3.13; p = 0.0005; and HR 1.77; p = 0.0389), and carcinoembryonic antigen (CEA) level of ≥100 ng/ml (HR 1.67; p = 0.032; and HR 1.67; p = 0.044). The presence of four criteria (PR, ≤3 CLM, ≤3 cm maximum size, and CEA ≤100 ng/ml) selected a subgroup (n = 23) with significantly higher probabilities for OS and RFS at 5 years (39% and 22%,respectively) compared to those without any or up 3 of these criteria (0-27% and 0-9%, p < 0.001, respectively).

Conclusions

A score based on four criteria (response to systemic therapy, ≤3 CLM, ≤3 cm size, low CEA value) may allow to select patients with liver-only CLM for whom additional use of RFA most likely adds benefit in an attempt to achieve long-term disease control. Almost one-fourth of patients fulfilling these four criteria may achieve 5-year survival without disease recurrence following effective systemic plus local RFA treatment.

Patterns of recurrence following selective intraoperative radiofrequency ablation as an adjunct to hepatic resection for colorectal liver metastases

BACKGROUND AND OBJECTIVES

The purpose of this study was to analyze the patterns of recurrence following intraoperative radiofrequency ablation (RFA) combined with hepatic resection for patients with colorectal liver metastases (CLM).

METHODS

Patients undergoing liver resection (with or without RFA) for CLM were examined. Rates and patterns of disease recurrence, as well as overall survival were assessed using Kaplan-Meier and Cox analyses.

RESULTS

A total of 174 patients underwent liver resection for CLM (150 without and 24 with intraoperative RFA). RFA was used to treat 41 tumors (median 1.6 cm). The 3-year overall survival was 65.5% and 61.4% (adjusted HR 1.02, 95% CI 0.55-1.88). Median recurrence-free survival was 7.4 versus 12.7 months with RFA versus non-RFA, respectively (adjusted HR 1.51, 95% CI 0.94-4.42). On multivariate analysis, neither survival nor recurrence-free survival was significantly associated with RFA. In total, there were two RFA ablation zone local failures. An ablation site recurrence was the sole site in one patient (4.2%).

CONCLUSION

RFA was used as an adjunct to resection in patients with greater disease burden. Despite this, RFA was not significantly associated with a higher risk of local failure and was not associated with worse survival, when compared with liver resection alone.

Strategies for Management of Synchronous Colorectal Metastases

The management of synchronous presentation of colorectal cancer and liver metastases has long been a topic of debate and discussion for surgeons due to the unique dilemma of balancing operative timing along with treatment strategy. Operative strategies for resection include staged resection with colon first approach, "reverse" staged resection with liver metastases resected first, and one-stage, or simultaneous, resection of both the primary tumor and liver metastases approach. These operative strategies can be further augmented with perioperative chemotherapy and other novel approaches that may improve resectability and patient survival. The decision on operative timing and approach, however, remains largely dependent on the surgeon's determination of disease resectability, patient fitness, and the need for neoadjuvant chemotherapy.

Colorectal cancer: from prevention to personalized medicine

Colorectal cancer (CRC) is a very heterogeneous disease that is caused by the interaction of genetic and environmental factors. CRC develops through a gradual accumulation of genetic and epigenetic changes, leading to the transformation of normal colonic mucosa into invasive cancer. CRC is one of the most prevalent and incident cancers worldwide, as well as one of the most deadly. Approximately 1235108 people are diagnosed annually with CRC, and 609051 die from CRC annually. The World Health Organization estimates an increase of 77% in the number of newly diagnosed cases of CRC and an increase of 80% in deaths from CRC by 2030. The incidence of CRC can benefit from different strategies depending on its stage: health promotion through health education campaigns (when the disease is not yet present), the implementation of screening programs (for detection of the disease in its early stages), and the development of nearly personalized treatments according to both patient characteristics (age, sex) and the cancer itself (gene expression). Although there are different strategies for screening and although the number of such strategies is increasing due to the potential of emerging technologies in molecular marker application, not all strategies meet the criteria required for screening tests in population programs; the three most accepted tests are the fecal occult blood test (FOBT), colonoscopy and sigmoidoscopy. FOBT is the most used method for CRC screening worldwide and is also the primary choice in most population-based screening programs in Europe. Due to its non-invasive nature and low cost, it is one of the most accepted techniques by population. CRC is a very heterogeneous disease, and with a few exceptions (APC, p53, KRAS), most of the genes involved in CRC are observed in a small percentage of cases. The design of genetic and epigenetic marker panels that are able to provide maximum coverage in the diagnosis of colorectal neoplasia seems a reasonable strategy. In recent years, the use of DNA, RNA and protein markers in different biological samples has been explored as strategies for CRC diagnosis. Although there is not yet sufficient evidence to recommend the analysis of biomarkers such as DNA, RNA or proteins in the blood or stool, it is likely that given the quick progression of technology tools in molecular biology, increasingly sensitive and less expensive, these tools will gradually be employed in clinical practice and will likely be developed in mass.

Thermal ablation of liver metastases from colorectal cancer: radiofrequency, microwave and laser ablation therapies

Surgery is currently considered the treatment of choice for patients with colorectal cancer liver metastases (CRLM) when resectable. The majority of these patients can also benefit from systemic chemotherapy. Recently, local or regional therapies such as thermal ablations have been used with acceptable outcomes. We searched the medical literature to identify studies and reviews relevant to radiofrequency (RF) ablation, microwave (MW) ablation and laser-induced thermotherapy (LITT) in terms of local progression, survival indexes and major complications in patients with CRLM. Reviewed literature showed a local progression rate between 2.8 and 29.7 % of RF-ablated liver lesions at 12-49 months follow-up, 2.7-12.5 % of MW ablated lesions at 5-19 months follow-up and 5.2 % of lesions treated with LITT at 6-month follow-up. Major complications were observed in 4-33 % of patients treated with RF ablation, 0-19 % of patients treated with MW ablation and 0.1-3.5 % of lesions treated with LITT. Although not significantly different, the mean of 1-, 3- and 5-year survival rates for RF-, MW- and laser ablated lesions was (92.6, 44.7, 31.1 %), (79, 38.6, 21 %) and (94.2, 61.5, 29.2 %), respectively. The median survival in these methods was 33.2, 29.5 and 33.7 months, respectively. Thermal ablation may be an appropriate alternative in patients with CRLM who have inoperable liver lesions or have operable lesions as an adjunct to resection. However, further competitive evaluation should clarify the efficacy and priority of these therapies in patients with colorectal cancer liver metastases.

Recurrence location after resection of colorectal liver metastases influences prognosis

AIM

To assess the impact of first recurrence location on survival following surgery of colorectal liver metastases.

METHODS

A total of 265 consecutive patients with colorectal liver metastases undergoing liver surgery (2000-2011) were categorized according to first site of tumor recurrence. Time to recurrence (TTR) and overall survival (OS) were determined. Uni- and multivariate analysis were performed to identify factors associated with TTR and OS.

RESULTS

Median TTR was 1.16 years following liver resection, and 0.56 years following radiofrequency ablation (RFA). Intrahepatic recurrence following liver resection resulted in a significantly shorter median TTR compared to extrahepatic recurrence. Intrapulmonary recurrence was associated with superior survival compared to other recurrence locations. Such patterns were not observed in the RFA-treated group. Multivariate analysis identified the type of surgical treatment and extra-hepatic first-site recurrence (other than lung) as independent predictors for OS. Pre-operative chemotherapy and simultaneous intrahepatic and extrahepatic recurrence were independent predictors for both TTR and OS.

CONCLUSIONS

Patients with intrahepatic recurrence following liver resection have a significantly shorter TTR and OS when compared to patients developing extrahepatic recurrence. Pulmonary recurrence following resection is associated with longer survival. Simultaneous intra- and extrahepatic recurrence is an independent prognostic factor for TTR and OS.

Surgical resection for local recurrence after radiofrequency ablation for colorectal liver metastasis is more extensive than primary resection

OBJECTIVE

As a minimally invasive modality, radiofrequency ablation (RFA) has been increasingly applied not only for the treatment of hepatocellular carcinoma, but also for that of colorectal liver metastasis (CLM). However, RFA for CLM has been shown to be associated with a high local recurrence rate, and no optimal treatment for RFA failure has been established yet. The aim of this study was to evaluate the feasibility and outcome of surgical resection for local recurrence after RFA.

MATERIAL AND METHODS

A retrospective study of 17 patients, who underwent surgery for local recurrence after RFA for resectable CLM, was carried out. The surgical procedures involved in the actual surgery were compared with those envisioned for the primary resection if RFA had not been selected.

RESULTS

Surgical resection for RFA recurrence was more invasive than the envisioned surgical procedure in 10 cases (58%). In addition, the proportions of cases that required technically demanding procedures among the patients receiving surgery for RFA recurrence were higher than those in envisioned operations; major hepatectomy, eight cases [47%] versus two cases [12%] (p<0.0205); excision and/or reconstruction of the major hepatic veins, three cases [18%] versus zero case [0%] (p=0.035); excision of diaphragm: three cases [18%] versus zero case [0%] (p=0.035). The 1-, 3- and 5-year overall survival rates were 92%, 45% and 45%, respectively.

CONCLUSIONS

Surgical resection for RFA recurrence for CLM required more invasive and technically demanding procedures. Thus, RFA for CLM should be limited to unresectable cases, and patients with resectable CLM should be thoroughly advised not to undergo RFA, but rather surgical resection.

Intraoperative electrochemotherapy of colorectal liver metastases

BACKGROUND AND OBJECTIVES

Electrochemotherapy is effective in treatment of various cutaneous tumors and could be translated into treatment of deep-seated tumors. With this aim a prospective pilot study was conducted to evaluate feasibility, safety, and efficacy of intraoperative electrochemotherapy in the treatment of colorectal liver metastases.

METHODS

Electrochemotherapy with bleomycin was performed during open surgery, by insertion of long needle electrodes into and around the tumor according to the individualized pretreatment plan.

RESULTS

A 29 metastases in 16 patients were treated in 16 electrochemotherapy sessions. No immediate (intraoperative) and/or postoperative serious adverse events related to electrochemotherapy were observed. Radiological evaluation of all the treated metastases showed 85% complete responses and 15% partial responses. In a group of seven patients that underwent a second operation at 6-12 weeks after the first one, during which electrochemotherapy was performed, the histology of resected metastases treated by electrochemotherapy showed less viable tissue (P = 0.001) compared to non-treated ones.

CONCLUSIONS

Electrochemotherapy of colorectal liver metastases proved to be feasible, safe, and efficient treatment modality, providing its specific place in difficult to treat metastases, located in the vicinity of major hepatic vessels, not amenable to surgery or radiofrequency ablation.

Stereotactic ablative radiotherapy for oligometastatic disease in liver

Liver metastasis in solid tumors, including colorectal cancer, is the most frequent and lethal complication. The development of systemic therapy has led to prolonged survival. However, in selected patients with a finite number of discrete lesions in liver, defined as oligometastatic state, additional local therapies such as surgical resection, radiofrequency ablation, cryotherapy, and radiotherapy can lead to permanent local disease control and improve survival. Among these, an advance in radiation therapy made it possible to deliver high dose radiation to the tumor more accurately, without impairing the liver function. In recent years, the introduction of stereotactic ablative radiotherapy (SABR) has offered even more intensive tumor dose escalation in a few fractions with reduced dose to the adjacent normal liver. Many studies have shown that SABR for oligometastases is effective and safe, with local control rates widely ranging from 50% to 100% at one or two years. And actuarial survival at one and two years has been reported ranging from 72% to 94% and from 30% to 62%, respectively, without severe toxicities. In this paper, we described the definition and technical aspects of SABR, clinical outcomes including efficacy and toxicity, and related parameters after SABR in liver oligometastases from colorectal cancer.

Evolving ablative therapies for hepatic malignancy

The liver is a common site for both primary and secondary malignancy. Hepatic resection and transplantation are the two treatment modalities that have been shown to achieve complete cure, but only 10 to 20% of patients are candidates for these treatments. For the remaining patients, tumor ablation has emerged as the most promising alternative modality. In addition to providing local control and improving survival outcomes, tumor ablation also helps to down stage patients for potential curative treatments, both alone as well as in combination with other treatments. While tumor ablation can be achieved in multiple ways, the introduction of newer ablative techniques has shifted the focus from palliation to potentially curative treatment. Because the long-term safety and survival benefits are not substantive at present, it is important that we strive to evaluate the results from these studies using appropriate comparative outcome methodologies.

Clinical outcome of ultrasound-guided percutaneous microwave ablation on colorectal liver metastases

The present study aimed to assess the feasibility, safety and efficiency of ultrasound-guided percutaneous microwave ablation (MWA) on liver metastases from colon or rectal cancer. Patients who received MWA therapy for liver metastases from colon or rectal cancer between June 2009 and May 2012 were enrolled in the study. Follow-up data was collected from the patients in order to statistically analyze the adverse effects, concurrent disease and survival status. Of the total 115 patients, 62 presented with colon cancer and 53 with rectal cancer. A total of 78 patients were male and 37 were female. The patient age ranged between 30 and 86 years [mean ± standard deviation (SD), 59.46±11.79 years]. The number of overall ablation lesions was 165, and the diameter of the lesions ranged between 1.3 and 5.0 cm (mean ± SD, 3.10±1.05 cm). Subsequent to treatment, the mean (± SD) hospitalization time was 4.69±2.08 days (range, 2-10 days). The median follow-up time was 28 months (range, 12-48 months) and 5 patients were lost to follow-up. The pain grade was recorded between the 4th and 6th degree following treatment in 23 patients. The body temperatures of 35 patients reached >38°C, with the longest time at this temperature recorded as 5 days. Following treatment, 5 patients presented with pleural effusion and required thoracocentesis and drainage. Following ablation, the rate of local progression was 11.82%. The recurrence rates were 27.8, 48.4 and 59.3% and the cumulative survival rates were 98.1, 87.1 and 78.7% in years 1, 2 and 3 post-treatment, respectively. A total of 14 patients succumbed. No significant differences were observed in the liver metastases of colorectal cancer with regard to gender, age, number of lesions, lesion size and pathological differentiation (P>0.05). Also, no significant difference was observed in the recurrence or cumulative survival rates for years 1, 2 and 3 years post-treatment (P>0.05). In conclusion, ultrasound-guided percutaneous MWA is a safe and competent way to treat inoperable colorectal liver metastases.

Current management of colorectal liver metastases

SUMMARY 

Colorectal cancer is common worldwide and is predicted to become more so in the coming years. The liver is the most common site of metastasis and management is increasingly complex. A multidisciplinary team approach to management is essential, and is associated with better outcomes. Patients with irresectable liver metastases can still benefit from the involvement of a liver specialist, as high secondary resection rates can be achieved with combination chemotherapy, incorporating novel biological therapies and liver-directed local and locoregional treatments. The application of an enhanced recovery model to perioperative care, alongside improvements in the assessment of patient fitness for surgery, should help to mitigate the challenges presented by an older population with increased comorbidity undergoing increasingly complex treatment.

Local recurrence rates after radiofrequency ablation or resection of colorectal liver metastases. Analysis of the European Organisation for Research and Treatment of Cancer #40004 and #40983

AIM

The aim of this study is to describe local tumour control after radiofrequency ablation (RFA) and surgical resection (RES) of colorectal liver metastases (CLM) in two independent European Organisations for Research and Treatment of Cancer (EORTC) studies.

BACKGROUND

Only 10-20% of patients with newly diagnosed CLM are eligible for curative RES. RFA has found a place in daily practice for unresectable CLM. There are no prospective trials comparing RFA to RES for resectable CLM.

METHODS

The CLOCC trial randomised 119 patients with unresectable CLM between RFA (±RES)+adjuvant FOLFOX (±bevacizumab) versus FOLFOX (±bevacizumab) alone. The EPOC trial randomised 364 patients with resectable CLM between RES±perioperative FOLFOX. We describe the local control of resected patients with lesions ≤4 cm in the perioperative chemotherapy arm of the EPOC trial (N=81) and the RFA arm of the CLOCC trial (N=55).

RESULTS

Local recurrence (LR) rate for RES was 7.4% per patient and 5.5% per lesion. LR rate for RFA was 14.5% per patient and 6.0% per lesion. When lesion size was limited to 30 mm, LR rate for RFA lesions was 2.9% per lesion. Non-local hepatic recurrences were more often observed in RFA patients than in RES patients, 30.9% and 22.3% respectively. Patients receiving RFA had a more advanced disease.

CONCLUSIONS

LR rate after RFA for lesions with a limited size is low. The local control per lesion does not appear to differ greatly between RFA and surgical resection. This study supports the local control of RFA in patients with limited liver metastases. Future studies should evaluate in which patients RFA could be an equal alternative to liver resection.

Radiofrequency ablation for colorectal liver metastases

The management of hepatic metastases from colorectal cancer (HMCRC) is multimodal including chemotherapy, surgical resection, radiation therapy, and focused destruction technologies. Radiofrequency ablation (RFA) is the most commonly used focused destruction technology. It represents a therapeutic option that may be potentially curative in cases where surgical excision is contra-indicated. It also increases the number of candidates for surgical resection among patients whose liver metastases were initially deemed unresectable. This article explains the techniques, indications, and results of radiofrequency ablation in the treatment of hepatic colorectal metastases.

Laparoscopic liver resection compared to open approach in patients with colorectal liver metastases improves further resectability: Oncological outcomes of a case-control matched-pairs analysis

AIMS

Liver resection is considered the standard treatment of colorectal metastases (CRLM). However, to date, no long term oncological results and data regarding repeat hepatectomy after laparoscopic approach are known. The aim of this study is to analyze single center long-term surgical and oncological outcomes after liver resection for CRLM.

METHODS

A total of 57 open resections (OR) were matched with 57 laparoscopic resections (LR) for CRLM. Matching was based mainly on number of metastases, tumor size, segmental position of lesions, type of hepatectomy and type of resection.

RESULTS

Morbidity rate was significantly less in the LR group (p = 0.002); the length of hospital stay was 6.5 ± 5 days for the LR group and 9.2 ± 4 days for the OR group (p = 0.005). After a median follow up of 53.7 months for the OR group and 40.9 months for the LR group, the 5-y overall survival rate was 65% and 60% respectively (p = 0.36) and the 5-y disease free survival rate was 38% and 29% respectively (p = 0.24). More patients in the LR group received a third hepatectomy for CRLM relapse than in the OR group (80% vs. 14.3% respectively; p = 0.015).

CONCLUSIONS

Laparoscopic resection for CRLM offers advantages in terms of reduced blood loss, morbidity rate and hospital stay. It provides comparable long-term oncological outcomes but can improve further resectability in patients with recurrent disease.

Therapeutic efficacy comparison of radiofrequency ablation in hepatocellular carcinoma and metastatic liver cancer

The aim of this study was to evaluate the effect of radiofrequency ablation (RFA) on malignant hepatic tumors and compare its therapeutic efficacy in hepatocellular carcinoma (HCC) and metastatic liver cancer (MLC). A total of 56 patients with malignant hepatic tumors (34 patients with HCC and 22 patients with MLC) underwent RFA treatment. Two weeks following the RFA treatment, contrast-enhanced abdominal computed tomography scans were used to investigate whether the ablation of the tumors was complete. The patients were followed up for a period ranging from 1 to 93 months, to compare recurrence rates, distant recurrence rates and survival rates. The HCC group exhibited an initial complete ablation rate of 94.1% compared with 95.4% for the MLC group; the difference in ablation rates was not identified to be statistically significant. The recurrence and distant recurrence rates were 14.7% and 11.8%, respectively, for the HCC group and 9.1% and 36.4%, respectively, for the MLC group. The 1-, 3- and 5-year survival rates of the patients with HCC were 86.2, 71.4 and 60.0%, respectively, whereas those for the patients with MLC were 73.9%, 45.4% and 37.5%, respectively. The survival rates of the two groups were identified to be significantly different (P=0.002). RFA treatment was therefore shown to be effective in treating small (<5 cm) malignancies, which is clinically significant.

Complementary use of resection and radiofrequency ablation for the treatment of colorectal liver metastases: an analysis of 395 patients

BACKGROUND

Liver resection and radiofrequency ablation (RFA) are two surgical options in the treatment of patients with colorectal liver metastases (CLM). The aim of this study was to analyze patient characteristics and outcomes after resection and RFA for CLM from a single center.

METHODS

Between 2000 and 2010, 395 patients with CLM undergoing RFA (n = 295), liver resection (n = 94) or both (n = 6) were identified from a prospective IRB-approved database. Demographic, clinical and survival data were analyzed using univariate and multivariate analyses.

RESULTS

RFA patients had more comorbidities, number of liver tumors and a higher incidence of extrahepatic disease compared to the Resection patients. The 5-year overall actual survival was 17 % in the RFA, 58 % in the Resection group (p = 0.001). On multivariate analysis, multiple liver tumors, dominant lesion >3 cm, and CEA >10 ng/ml were independent predictors of overall survival. Patients were followed for a median of 20 ± 1 months. Liver and extrahepatic recurrences were seen in 69 %, and 29 % of the patients in the RFA, and 40 %, and 19 % of the patients in the Resection group, respectively.

CONCLUSIONS

In this large surgical series, we described the characteristics and oncologic outcomes of patients undergoing resection or RFA for CLM. By having both options available, we were able to surgically treat a large number of patients presenting with different degrees of liver tumor burden and co-morbidities, and also manage liver recurrences in follow-up.

Incidence and treatment of local site recurrences following RFA of colorectal liver metastases

BACKGROUND

Patients with colorectal liver metastases (CRLM) who are ineligible for curative surgery are potential candidates for radiofrequency ablation (RFA). Although RFA has emerged as a well accepted and documented treatment modality, there are still some reservations because of initially high rates of local site recurrences (LSR). The aim of the present study was to evaluate LSR levels following RFA treatment, with a specific focus on re-treatment and survival.

PATIENTS AND METHODS

All patients ineligible for curative resection of CRLM and undergoing RFA alone or in combination with resection were prospectively included from July 2000 to December 2010 and retrospectively analyzed. Patients with untreatable extrahepatic disease were excluded. FDG PET-CT was conducted at 3-6 month intervals after RFA. Patients with LSR were evaluated for re-treatment.

RESULTS

A total of 132 patients were treated with RFA, which was combined with resection in 64 patients. A total of 290 lesions were ablated, with a mean number of 2.19 per patient and a mean size of 2.2 cm. Median survival was 41 months, with a 3- and 5-year survival of, respectively, 60 and 30.8 %. Following initial RFA, 39 patients developed an LSR in 40 ablated lesions, and local recurrence was strongly related to lesion size. Re-treatment could be performed in 26/39 patients, of whom eight remained disease-free.

CONCLUSIONS

Radiofrequency ablation can be applied to CRLM of less than 3 cm with curative intent. In the absence of extensive intrahepatic or extrahepatic disease, renewed treatment of local recurrences should be considered and is often successful.