Radiofrequency Ablation Of Hepatic Metastases Research Articles

The use of medical imaging methods for percutaneous radiofrequency ablation of hepatic metastases of colorectal cancer

The use of medical imaging methods for percutaneous radiofrequency ablation of hepatic metastases of colorectal cancer

Characteristic changes of the ablation zone on contrast-enhanced computed tomography after radiofrequency ablation of hepatic metastases.

Purpose:Size and density measurements of the ablation zones on contrast-enhanced computed tomography (CT) after radiofrequency ablation (RFA) of hepatic metastases of primary breast or colorectal cancer were acquired over time.Materials and Methods:Twenty-five liver metastases [colorectal cancer (CRC): n = 16; mean size: 19.6 ± 8.5 mm; breast cancer (BC): n = 9; 27.9 ± 13.6 mm] in 15 patients (CRC: n = 11; age: 65.4 ± 6.5 years; BC: n = 4; 62.0 ± 13.8 years) treated by RFA were included in this retrospective study. All patients had undergone postinterventional serial follow-up using multidetector CT (MDCT) (1 day/1/4/7/10/14/18/23/>24 months) without evidence of local tumor recurrence during the follow-up. The ablation zones were evaluated using a commercial software tool (Syngo CT Oncology) in order to determine volumetric, RECIST-, WHO- and density changes over the course of time. Results were compared by applying repeated measures analysis of variance and displayed graphically.Results:The RF ablation zones demonstrated significant shrinkage (P ≤ 0.05) over the first 7 months (volume, RECIST, WHO) of the follow-up. Follow-up after 7 months did not show any significant changes in size (P > 0.05) (mean volume (ml): 55.2/34.7/26.3/16.5/12.7/10.0/8.9/8.1/7.5; RECIST (mm): 58.7/49.3/43.7/37.8/34.2/31.3/29.1/27.3/24.8; WHO (mm2): 2458.3/1769.3/1341.8/1027.1/870.1/720.2/649.0/570.4/511.3). Mean density values decreased significantly between 1 day (58.9 HU) and 1 month (47.5 HU) after the procedure.Conclusion:Typical changes in size and density values of RF-induced, recurrence-free ablation zones after RFA of hepatic metastases of colorectal and breast cancer were acquired, showing a significant decrease in density of the ablation zone within the first month and significant shrinkage within the first 7 months after RFA.

Duodenorenal Fistula as a Complication of Radiofrequency Ablation of Hepatic Metastasis of Renal Cell Carcinoma

Duodenorenal Fistula as a Complication of Radiofrequency Ablation of Hepatic Metastasis of Renal Cell Carcinoma

Safety and Efficacy of Radiofrequency Ablation for Hepatic Metastases from Gastrointestinal Stromal Tumor

To evaluate the safety and efficacy of radiofrequency (RF) ablation for hepatic metastases from gastrointestinal stromal tumor (GIST). Retrospective review of a prospectively maintained database was performed between February 2002 and November 2010 and identified 29 patients with GISTs (18 male; age range, 35–77 y; median age, 61 y) who had undergone ultrasound-guided RF ablation for metastases detected in the liver. All patients had been treated with imatinib mesylate. Indications for RF ablation were tumor progression during medical therapy or the development of drug resistance after initial tumor control. The average number of target lesions per procedure was 2.3 (range, 1–8), and mean lesion diameter was 1.3 cm (range, 0.4–3.6 cm). For 69 lesions among 86 hepatic metastases, RF ablation was successfully performed according to the protocol currently in use. In 17 hepatic metastases in 13 patients, RF ablation was not performed because of poor lesion visibility or possible thermal damage to adjacent organs. Major complications included bleeding at the ablation site in one patient and peritoneal seeding near the ablation tract in another patient. Technical effectiveness was achieved for 66 of 69 lesions (95.6%). The median follow-up period was 33.1 months (range, 12.3–108.6 mo). Four of 66 lesions (6%) showed local recurrence at 3.2–10.5 months. Four patients died of disease progression. The median overall survival period was 90.2 months (range, 12.3–108.6 mo). RF ablation appears to be a safe and effective treatment for hepatic metastases of GIST when medical therapy fails.

Percutaneous Radiofrequency Ablation of Hepatic Metastases from Gastric Adenocarcinoma after Gastrectomy

PurposeTo evaluate the efficacy of percutaneous radiofrequency (RF) ablation for treatment of hepatic metastases from gastric adenocarcinoma. Materials and MethodsOf 24 patients who underwent percutaneous RF ablation after gastrectomy for a hepatic metastasis from a gastric cancer during the period 2000–2013, 19 were enrolled (median age, 63 y) with 21 metastatic tumors (mean diameter, 2.3 cm). Patient overall survival (OS) and local tumor progression-free survival (PFS) outcomes were assessed and compared according to patient and tumor characteristics, including tumor size and lobar distribution. The difference in diameter between tumor and ablation zone was compared according to lobar distribution. ResultsThe median OS after RF ablation was 20.3 months, and the median local tumor PFS was 10.4 months. The OS rate was not significantly influenced by any patient or tumor characteristics. In multivariate analysis, independent negative prognostic factors for local tumor PFS were a tumor ≥ 3 cm in diameter (hazard ratio, 10.5; 95% confidence interval, 1.8–62.5; P = .009) and a tumor located in the left lobe (hazard ratio, 9.1; 95% confidence interval, 1.3–63.5; P = .026). The difference in diameter between the tumor and ablation zone was significantly different between the right and left lobes (right 1.8 cm ± 0.6 vs left 1.1 cm ± 0.70, P = .028). ConclusionsWith the appropriate selection of patients with tumors ≤ 3 cm in diameter and with the possibility of sufficient safety margins, RF ablation is a safe and feasible treatment option for hepatic metastases from gastric adenocarcinoma.

Radiofrequency ablation of hepatic metastases: factors influencing local tumor progression.

Although radiofrequency ablation (RFA) of nonresectable hepatic metastases has gained wide acceptance by showing survival benefit in selected patients, scattered reports are available regarding risk factors of local control of percutaneous RFA. The purpose of this study was to prospectively evaluate the factors influencing local tumor progression after percutaneous RFA of hepatic metastases. Sixty-nine hepatic metastatic lesions in 54 patients were treated by percutaneous RFA. Efficacy was evaluated by contrast-enhanced computed tomography or magnetic resonance imaging at 1 month after ablation, then at 3-month intervals for the first year and biannually thereafter. The results of the log-rank test showed that tumor size of <3 cm (p = 0.024) and the absence of tumor contiguous with large vessels (p = 0.002) significantly correlated with local control for hepatic metastases. Cox regression analysis showed that the tumor size <3 cm and the absence of tumor contiguous with large vessels were independent factors (p = 0.055 and 0.009, respectively). The results of the log-rank test showed that neither the threshold post-ablation margin of 1.8 cm (p = 0.064) nor the presence of a tumor with subcapsular location (p = 0.134) correlated with the success of local control. Percutaneous RFA is more effective in achieving local control in patients with hepatic metastases when the tumor size is <3 cm and not contiguous with large vessels.

Radiofrequency Ablation of Hepatic Metastases After Curative Resection of Extrahepatic Cholangiocarcinoma

The objective of our study was to retrospectively evaluate local control and survival after radiofrequency ablation (RFA) in patients with liver metastases arising from extrahepatic cholangiocarcinoma who had previously undergone curative resection. From May 2003 to May 2009, RFA using an internally cooled electrode was performed on 29 metachronous liver metastases (mean number of tumors per patient, 1.6) arising from extrahepatic cholangiocarcinoma in 18 patients (mean age, 66 years). Tumor size ranged from 0.9 to 4.6 cm in maximum dimension (mean, 2.3 cm). As historical comparisons, we included 24 patients diagnosed with recurrent metastasis limited to the liver between February 1997 and April 2003 and who met the inclusion criteria for RFA: 16 patients received supportive therapy only and eight patients underwent chemotherapy with or without radiation. Five patients had major complications (liver abscess, n = 4 patients; biliary stricture, n = 1; 17% per-treatment complication rate [5/29]), but there were no procedure-related deaths. Complete tumor necrosis was achieved in all 29 tumors after one session of RFA. The local tumor progression rate was 38% (median time to detection, 5 months). From the first diagnosis of liver metastasis, the median overall survival was 12.4 months and the 3-year survival rate was 10%. Patients who received RFA lived significantly longer than patients who received chemoradiotherapy (median survival, 5.6 months) and those who received supportive treatment (median survival, 5.3 months) (p < 0.001). Percutaneous RFA results in effective local tumor control and may prolong survival in patients with recurrent hepatic metastases after curative resection for extrahepatic cholangiocarcinoma.

P.1.85: HIGH RISK OF SEVERE HEPATIC ABSCESS, AS COMPLICATION OF RADIOFREQUENCY ABLATION OF HEPATIC METASTASIS, IN PATIENTS WITH ENTERO-BILIARY ANASTOMOSIS

Poster: ECR 2010 / C-1971 / High risk of severe hepatic abscess, as complication of radiofrequency ablation of hepatic metastasis, in patients with entero-biliary anastomosis by: L. Tarantino1, V. Nocera2, P. Sperlongano3, C. Ripa2, I. Sordelli2, M. Celiento2, O. Tambaro2, R. Palmieri2, M. Perrotta2; 1Frattamaggiore/IT, 2Frattamaggiore (NA)/IT, 3Naples/IT

American Society of Clinical Oncology 2009 Clinical Evidence Review on Radiofrequency Ablation of Hepatic Metastases From Colorectal Cancer

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM). The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library. Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches. There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria

The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency (RF), laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's intention that adherence to the recommendations will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes. The intent of this standardization of terminology is to provide an appropriate vehicle for reporting the various aspects of image-guided ablation therapy.

Incorporation of Preprocedural PET into CT-Guided Radiofrequency Ablation of Hepatic Metastases: a Nonrigid Image Registration Validation Study

This study evaluates the accuracy of augmenting initial intraprocedural computed tomography (CT) during radiofrequency ablation (RFA) of hepatic metastases with preprocedural positron emission tomography (PET) through a hardware-accelerated implementation of an automatic nonrigid PET-CT registration algorithm. The feasibility of augmenting intraprocedural CT with preprocedural PET to improve localization of CT-invisible but PET-positive tumors with images from actual RFA was explored. Preprocedural PET and intraprocedural CT images from 18 cases of hepatic RFA were included. All PET images in the study originated from a hybrid PET/CT scanner, and PET-CT registration was performed in two ways: (1) direct registration of preprocedural PET with intraprocedural CT and (2) indirect registration of preprocedural CT (i.e., the CT of hybrid PET/CT scan) with intraprocedural CT. A hardware-accelerated registration took approximately 2 min. Calculated registration errors were 7.0 and 8.4 mm for the direct and indirect methods, respectively. Overall, the direct registration was found to be statistically not distinct from that performed by a group of clinical experts. The accuracy, execution speed, and compactness of our implementation of nonrigid image registration suggest that existing PET can be overlaid on intraprocedural CT, promising a novel, technically feasible, and clinically viable approach for PET augmentation of CT guidance of RFA.

Open Surgical is Superior to Percutaneous Access for Radiofrequency Ablation of Hepatic Metastases

This study was designed to determine the best approach to radiofrequency ablation (RFA) in the liver. From a total of 41 procedures, 37 patients with 47 tumors were treated with RFA for metastatic disease. Indications included colorectal cancer (n=28, 68%), neuroendocrine tumors (n=2, 5%), gynecological primaries (n=4, 10%), pancreatic/duodenal cancer (n=2, 5%), and miscellaneous entities (n=5, 12%). Mean follow-up period was 18 (median, 18) months. All ways of approach to RFA were applied: percutaneous was chosen in 17 (41.5%), laparoscopic and hand-assisted laparoscopic in 5 (12.2%), and open surgical in 19 cases (46.3%), and in 10 cases, RFA was combined with hepatic resection. The average maximum tumor size was 2.3 (range, 0.8-6) cm, and the mean number of nodules treated per patient in a single session was 1.3 (range, 1-3). Overall survival was 59.5% at 2 years, recurrence-free 2-year survival was 12.6%, local tumor recurrence rate was 34%, and overall recurrence was 75.6%. Local tumor recurrence and disease-free survival were significantly improved in the open surgically treated patients compared with the percutaneous treatment group (15.8% [n=3] vs. 58.8% [n=10] and 11.5 vs. 7.9 months, p<0.01 [chi2 test] and p<0.05 [log-rank test], respectively). Open surgical approach is superior to percutaneous access for RFA in metastatic hepatic disease.

Radiofrequency Ablation of Hepatic Metastases from Thyroid Carcinoma

Radiofrequency ablation (RFA) is performed for various types of liver tumors. It might also have a role in the palliative treatment of liver metastases from thyroid carcinoma. Three patients with liver metastases of thyroid carcinoma were retrieved from our database of 125 patients who had been treated with RFA for liver tumors. In all three patients, the metastases were a sign of widespread disease, and several other treatment modalities had been performed earlier. Two patients had metastases from medullary thyroid carcinoma and had severe diarrhea. The third patient had a rapidly progressive metastasis of a follicular thyroid carcinoma. The aim of the treatment was cytoreduction with amelioration of symptoms (n = 2) and debulking with increased sensitivity for subsequent (131)I treatment. The ablation was performed via laparotomy (n = 1), laparoscopically (n = 1), or percutaneously (n = 1). One patient experienced superficial burn wounds after a long-lasting RFA procedure. Severity of symptoms was reduced significantly after RFA for a prolonged period of time. RFA induced partial tumor necrosis because of hypervascularization of the tumor in one patient. After arterial embolization the second RFA treatment induced total tumor necrosis. Local recurrences at the site of the ablated liver metastases were not encountered during follow-up. RFA is a useful treatment modality in patients with liver metastases from thyroid carcinoma. It should be considered an adjunct to other types of treatment or for those patients in whom more regular treatment modalities are not effective or possible or are associated with increased risks.

Multipolar Hepatic Radiofrequency Ablation Using up to Six Applicators: Preliminary Results

To evaluate the clinical feasibility and safety of hepatic radiofrequency (RF) ablation using a multipolar RF system permitting the simultaneous use of up to six electrodes. Ten patients (3 female, 7 male, mean age 61) suffering from 29 hepatic metastases (range: 1 - 5) of different tumors were treated with a modified multipolar RF system (CelonLab Power, Celon Medical Instruments, Teltow, Germany) operating four to six needle-shaped internally cooled RF applicators. The procedure duration, applied energy and generator output were recorded during the intervention. The treatment result and procedure-related complications were analyzed. The achieved coagulation volume was calculated on the basis of contrast-enhanced CT scans 24 hours after RF ablation. Complete tumor ablation was achieved in all cases as determined by the post-interventional lack of contrast enhancement in the target region using four applicators in five patients, five applicators in one patient and six applicators in four patients. A mean energy deposition of 353.9 +/- 176.2 kJ resulted in a mean coagulation volume of 115.9 +/- 79.5 cm (3). The mean procedure duration was 74.9 +/- 21.2 minutes. Four patients showed an intraabdominal hemorrhage which necessitated further interventional treatment (embolization; percutaneous histoacryl injection) in two patients. Multipolar RF ablation of hepatic metastasis with up to six applicators was clinically feasible. In our patient population it was associated with an increased risk of intraabdominal bleeding probably due to the multiple punctures associated with the use of multiple applicators.

Radiofrequency ablation of hepatic metastasis: Results of treatment in forty patients

To evaluate the local control of hepatic metastasis with radiofrequency ablation treatment. We did a retrospective analysis in 40 patients treated with radiofrequency ablation for hepatic metastasis. The tumors ablated included up to two metastatic liver lesions, with primaries in breast, gastrointestinal tract, cervix, etc. Radiofrequency ablation was performed under general anesthesia in all cases, using ultrasound guidance. Radionics Cool-Tip RF System was used to deliver the treatment. The median age of patients treated was 49 years. There were 13 female and 27 male patients. The median tumor size ablated was 1.5 cm (0.75-4.0 cm). A total of 52 radiofrequency ablation cycles were delivered. Successful ablation was achieved in all patients with hepatic metastasis less than 3 cm in size. Pain was the most common complication seen (75%). One patients developed skin burns. At 2-year follow-up 7.5% of patients had locally recurrent disease. Radiofrequency ablation is a minimally invasive treatment modality. It can be useful in a select group of patients with solitary liver metastasis of less than 3 cm size.

Radiofrequency ablation in liver metastasis: Authors′ reply

. Radiofrequency interstitial thermal ablation of metastatic liver tumors. Int Congr Series 2001;1230:1070-5.2. Livraghi T, Solbiati L, Meloni F, Ierace T, Goldberg SN, Gazelle GS. Percutaneous radiofrequency ablation of liver metastases in potential candidates for resection: The fiTest-of-Timefl approach. Cancer 2003;97:3027-35.3. Rath GK, Julka PK, Thulkar S, Sharma DN, Bahl A, Bhatnagar S. Radiofrequency ablation of hepatic metastasis: Results of treatment in forty patients. J Cancer Res Ther 2008;4:14-7.4. Leblanc F, Fonck M, Brunet R, Becouarn Y, Mathoulin-POlissier S, Evrard S. Comparison of hepatic recurrences after resection or intraoperative radiofrequency ablation indicated by size and topographical characteristics of the metastases. Eur J Surg Oncol 2008;34:185-90. 5. Oshowo A, Gillams A, Harrison E, Lees WR, Taylor I. Comparison of resection and radiofrequency ablation for treatment of solitary colorectal liver metastases. Br J Surg 2003;90:1240-3.

Two-Stage Surgical Treatment of Unresectable Obstructive Rectal Cancer with Synchronous Hepatic Metastases

Unresectable obstructing rectal cancer with synchronous hepatic metastases is usually a fatal disease. This prospective study was scheduled to treat this difficult condition using a multimodal curative strategy combined with a two-stage surgical treatment. Patients with T4N2 or N3M1 rectal cancer and hepatic metastases underwent a two-stage surgical treatment; in the first stage, a decompressing colostomy plus radiofrequency ablation (RFA) in liver metastases. In the second stage, a colectomy was done with stoma closing and resection of superficial necrotic hepatic tumors, plus repetition of RFA in recurrent or new hepatic tumors. Four patients were included, with 1 to 8 (total 20) hepatic metastases, each <5 cm in diameter. In the first stage, two patients were operated on by open approach and two laparoscopically. All hepatic tumors were treated by RFA to produce at least a 1-cm tumor-free margin. After chemoradiation of the rectal tumor, the second stage of surgical treatment was successful in colectomies and stoma closing. Three had complete necrosis of hepatic tumors and one a recurrent tumor plus two new metastases treated by RFA. Two patients died 14 and 42 months after the first stage of surgical treatment, and the other two patients are alive. One of them is disease-free 54 months after the first stage and the other with new recurrence 52 months after the first stage of the procedure. The multimodal curative strategy for the treatment of unresectable obstructing rectal cancer with synchronous hepatic metastases, containing a two-stage surgical treatment with RFA of hepatic metastases and chemoradiation of the rectal tumor between the two stages of the procedure, is a promising method. A larger number of patients with long-term follow-up is necessary to confirm these findings.

Radiofrequency Ablation of Hepatic Metastases from Colorectal Cancer: Are Newer Generation Probes Better?

Second-generation radiofrequency ablation (RFA) probes and their successors have more power, shorter ablation times, and an increased area of ablation compared with the first-generation probes used before 2000. We examined whether the use of the newer probes has improved the clinical outcome of RFA for hepatic metastases of colorectal cancer at our tertiary cancer center. Of 160 patients who underwent RFA between 1997 and 2003, 52 had metastases confined to the liver: 21 patients underwent 46 ablations with the first-generation probes and 31 patients underwent 58 ablations with the newer probes. The two groups had similar demographic characteristics. At a median follow-up of 26.2 months, patients treated with the newer probes had a longer median disease-free survival (16 months vs 8 months, P < 0.01) and a lower rate of margin recurrence (5.2% vs 17.4%); eight patients had no evidence of disease and one patient was alive with disease. By contrast, of the 46 patients treated with the first-generation probes, 2 patients had no evidence of disease and 1 patient was alive with disease. Newer-generation probes are associated with lower rates of margin recurrence and higher rates of disease-free survival after RFA of hepatic metastases from colorectal cancer.

Contrast Enhanced Ultrasound for Radio Frequency Ablation of Canine Prostates: Initial Results

We determined the feasibility of contrast enhanced ultrasound for radio frequency ablation of the entire prostate as a method of minimally invasive treatment for prostate cancer in a canine model. Approval of the Institutional Animal Use and Care committee was obtained. Initially 5 dogs (group 1) were tested using variable power (5 to 30 W), time (4 to 12 minutes), bolus (0.01 to 0.04 ml/kg) and infusion (3 to 11 ml per minute at 0.015 microl/kg) injections of an ultrasound contrast agent with conventional grayscale power Doppler and pulse inversion harmonic imaging to establish optimal parameters. Subsequently 4 dogs (group 2) underwent entire prostate ablation using parameters based on group 1. The size of the thermal lesions and residual viable tissue was measured with ImageJ software (National Institutes of Health, Bethesda, Maryland) on ultrasound and pathological study. Linear regression and Student's t test were used for statistical analysis. A bolus of 0.04 ml/kg, an infusion of 11 ml per minute at 0.015 microl/kg and the contrast enhanced pulse inversion harmonic imaging mode were ranked best for guiding ablation. Thermal lesion volume was proportional to ablation power and time. There was no significant difference in measured thermal lesion size in group 1 between ultrasound and pathological findings (mean +/- SD 1.51 +/- 0.74 and 1.46 +/- 0.74 cm3, p = 0.56) or in residual viable tissue in group 2 (0.43 +/- 0.043 and 0.41 +/- 0.291 cm3, p = 0.21). The average volume of prostate ablation achieved in group 2 was 96.3%. Contrast enhanced pulse inversion harmonic imaging is able to guide, monitor and control radio frequency ablation of the entire prostate.

Multipolar radiofrequency ablation of large hepatic metastases of endocrine tumours

Radiofrequency ablation (RFA) is a reliable method of creating thermally induced coagulation necrosis. Local recurrence after RFA of hepatic metastases is directly dependent on tumour size related to the free margin of ablation. To produce larger coagulation volumes a bipolar radiofrequency device was developed that allows the simultaneous activation of three active needles. This technique was used at laparotomy in a patient with liver metastases of an endocrine tumour. Coagulation size up to 12 cm in diameter could be created. The postoperative recovery of the patient was uncomplicated. No local recurrence was seen after 13 months of follow-up with computed tomography scan. The use of simultaneously operated multiple radiofrequency electrodes in a multipolar mode expands the treatment options for patients with large and unresectable intrahepatic metastases.