Microwave coagulation for liver metastases

Transarterial (chemo)embolisation versus systemic chemotherapy for colorectal cancer liver metastases

BACKGROUND

The liver is affected by two groups of malignant tumours: primary liver cancers and liver metastases. Liver metastases are significantly more common than primary liver cancer, and five-year survival after radical surgical treatment of liver metastases ranges from 28% to 50%, depending on primary cancer site. However, R0 resection (resection for cure) is not feasible in most people; therefore, other treatments have to be considered in the case of non-resectability. One possible option is based on the concept that the blood supply to hepatic tumours originates predominantly from the hepatic artery. Transarterial chemoembolisation (TACE) of the peripheral branches of the hepatic artery can be achieved by administering a chemotherapeutic drug followed by vascular occlusive agents and can lead to selective necrosis of the cancer tissue while leaving normal liver parenchyma virtually unaffected. The entire procedure can be performed without infusion of chemotherapy and is then called bland transarterial embolisation (TAE). These procedures are usually applied over a few sessions. Another possible treatment option is systemic chemotherapy which, in the case of colorectal cancer metastases, is most commonly performed using FOLFOX (folinic acid, 5-fluorouracil, and oxaliplatin) and FOLFIRI (folinic acid, 5-fluorouracil, and irinotecan) regimens applied in multiple sessions over a long period of time. These therapies disrupt the cell cycle, leading to death of rapidly dividing malignant cells. Current guidelines determine the role of TAE and TACE as non-curative treatment options applicable in people with liver-only or liver-dominant metastatic disease that is unresectable or non-ablatable, and in people who have failed systemic chemotherapy. Regarding the treatment modalities in people with colorectal cancer liver metastases, we found no systematic reviews comparing the efficacy of TAE or TACE versus systemic chemotherapy.

OBJECTIVES

To evaluate the beneficial and harmful effects of transarterial embolisation (TAE) or transarterial chemoembolisation (TACE) compared with systemic chemotherapy in people with liver-dominant unresectable colorectal cancer liver metastases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, and three additional databases up to 4 April 2024. We also searched two trials registers and the European Medicines Agency database and checked reference lists of retrieved publications.

SELECTION CRITERIA

We included randomised clinical trials assessing beneficial and harmful effects of TAE or TACE versus systemic chemotherapy in adults (aged 18 years or older) with colorectal cancer liver metastases.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality; overall survival (time to mortality); and any adverse events or complications. Our secondary outcomes were cancer mortality; health-related quality of life; progression-free survival; proportion of participants dying or surviving with progression of the disease; time to progression of liver metastases; recurrence of liver metastases; and tumour response measures (complete response, partial response, stable disease, and progressive disease). For the purpose of the review and to perform necessary analyses, whenever possible, we converted survival rates to mortality rates, as this was our primary outcome. For the analysis of dichotomous outcomes, we used the risk ratio (RR); for continuous outcomes, we used the mean difference; and for time to event outcomes, we calculated hazard ratios (HRs), all with 95% confidence intervals (CI). We used the standardised mean difference with 95% CIs when the trials used different instruments. We used GRADE to assess the certainty of evidence for each outcome. We based our conclusions on outcomes analysed at the longest follow-up.

MAIN RESULTS

We included three trials with 118 participants randomised to TACE versus 120 participants to systemic chemotherapy. Four participants were excluded; one due to disease progression prior to treatment and three due to decline in health. The trials reported data on one or more outcomes. Two trials were performed in China and one in Italy. The trials differed in terms of embolisation techniques and chemotherapeutic agents. Follow-up ranged from 12 months to 50 months. TACE may reduce mortality at longest follow-up (RR 0.86, 95% CI 0.79 to 0.94; 3 trials, 234 participants; very low-certainty evidence), but the evidence is very uncertain. TACE may have little to no effect on overall survival (time to mortality) (HR 0.61, 95% CI 0.37 to 1.01; 1 trial, 70 participants; very low-certainty evidence), any adverse events or complications (3 trials, 234 participants; very low-certainty evidence), health-related quality of life (2 trials, 154 participants; very low-certainty evidence), progression-free survival (1 trial, 70 participants; very low-certainty evidence), and tumour response measures (presented as the overall response rate) (RR 1.81, 95% CI 1.11 to 2.96; 3 trials, 234 participants; very low-certainty evidence), but the evidence is very uncertain. No trials reported cancer mortality, proportion of participants dying or surviving with progression of the disease, and recurrence of liver metastases. We found no trials comparing the effects of TAE versus systemic chemotherapy in people with colorectal cancer liver metastases.

AUTHORS' CONCLUSIONS

The evidence regarding effectiveness of TACE versus systemic chemotherapy in people with colorectal cancer liver metastases is of very low certainty and is based on three trials. Our confidence in the results is limited due to the risk of bias, inconsistency, indirectness, and imprecision. It is very uncertain whether TACE confers benefits with regard to reduction in mortality, overall survival (time to mortality), reduction in adverse events or complications, improvement in health-related quality of life, improvement in progression-free survival, and tumour response measures (presented as the overall response rate). Data on cancer mortality, proportion of participants dying or surviving with progression of the disease, and recurrence of liver metastases are lacking. We found no trials assessing TAE versus systemic chemotherapy. More randomised clinical trials are needed to strengthen the body of evidence and provide insight into the benefits and harms of TACE or TAE in comparison with systemic chemotherapy in people with liver metastases from colorectal cancer.

Microwave coagulation for liver metastases

BACKGROUND

Liver metastases (i.e. secondary hepatic malignancies) are significantly more common than primary liver cancer. Long-term survival after radical surgical treatment is approximately 50%. For people in whom resection for cure is not feasible, other treatments must be considered. One treatment option is microwave coagulation utilising electromagnetic waves. It involves placing an electrode into a lesion under ultrasound or computed tomography guidance.

OBJECTIVES

To evaluate the beneficial and harmful effects of microwave coagulation versus no intervention, other ablation methods, or systemic treatments in people with liver metastases regardless of the location of the primary tumour.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest date of search was 14 April 2023.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial or harmful effects of microwave coagulation and its comparators in people with liver metastases, irrespective of the location of the primary tumour. We included trials no matter the outcomes reported.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures. Our primary outcomes were: all-cause mortality at the last follow-up and time to mortality; health-related quality of life (HRQoL); and any adverse events or complications. Our secondary outcomes were: cancer mortality; disease-free survival; failure to clear liver metastases; recurrence of liver metastases; time to progression of liver metastases; and tumour response measures. We used risk ratios (RR) and hazard ratios (HR) with 95% confidence intervals (CI) to present the results. Two review authors independently extracted data and assessed the risk of bias using the Cochrane RoB 1 tool. We used GRADE methodology to assess the certainty of the evidence.

MAIN RESULTS

Three randomised clinical trials fulfilled the inclusion criteria. The control interventions differed in the three trials; therefore, meta-analyses were not possible. The trials were at high risk of bias. The certainty of evidence of the assessed outcomes in the three comparisons was very low. Data on our prespecified outcomes were either missing or not reported. Microwave coagulation plus conventional transarterial chemoembolisation (TACE) versus conventional TACE alone One trial, conducted in China, randomised 50 participants (mean age 60 years, 76% males) with liver metastases from various primary sites. Authors reported that the follow-up period was at least one month. The trial reported adverse events or complications in the experimental group only and for tumour response measures. There were no dropouts in the trial. The trial did not report on any other outcomes. Microwave ablation versus conventional surgery One trial, conducted in Japan, randomised 40 participants (mean age 61 years, 53% males) with multiple liver metastases of colorectal cancer. Ten participants were excluded after randomisation (six from the experimental and four from the control group); thus, the trial analyses included 30 participants. Follow-up was three years. The reported number of deaths from all causes was 9/14 included participants in the microwave group versus 12/16 included participants in the conventional surgery group. The mean overall survival was 27 months in the microwave ablation and 25 months in the conventional surgery group. The three-year overall survival was 14% with microwave ablation and 23% with conventional surgery, resulting in an HR of 0.91 (95% CI 0.39 to 2.15). The reported frequency of adverse events or complications was comparable between the two groups, except for the required blood transfusion, which was more common in the conventional surgery group. There was no intervention-related mortality. Disease-free survival was 11.3 months in the microwave ablationgroup and 13.3 months in the conventional surgery group. The trial did not report on HRQoL. Microwave ablation versus radiofrequency ablation One trial, conducted in Germany, randomised 50 participants (mean age 62.8 years, 46% males) who were followed for 24 months. Two-year mortality showed an RR of 0.62 (95% CI 0.26 to 1.47). The trial reported that, by two years, 76.9% of participants in the microwave ablationgroup and 62.5% of participants in the radiofrequency ablation group survived (HR 0.63, 95% CI 0.23 to 1.73). The trial reported no deaths or major complications during the procedures in either group. There were two minor complications only in the radiofrequency ablation group (RR 0.19, 95% CI 0.01 to 3.67). The trial reported technical efficacy in 100% of procedures in both groups. Distant recurrence was reported for 10 participants in the microwave ablation group and nine participants in the radiofrequency ablation group (RR 1.03, 95% CI 0.50 to 2.08). No participant in the microwave ablation group demonstrated local progression at 12 months, while that occurred in two participants in the radiofrequency ablation group (RR 0.19, 95% CI 0.01 to 3.67). The trial did not report on HRQoL. One trial reported partial support by Medicor (MMS Medicor Medical Supplies GmbH, Kerpen, Germany) for statistical analysis. The remaining two trials did not provide information on funding. We identified four ongoing trials.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effect of microwave ablation in addition to conventional TACE compared with conventional TACE alone on adverse events or complications. We do not know if microwave ablation compared with conventional surgery may have little to no effect on all-cause mortality. We do not know the effect of microwave ablation compared with radiofrequency ablation on all-cause mortality and adverse events or complications either. Data on all-cause mortality and time to mortality, HRQoL, adverse events or complications, cancer mortality, disease-free survival, failure to clear liver metastases, recurrence of liver metastases, time to progression of liver metastases, and tumour response measures were either insufficient or were lacking. In light of the current inconclusive evidence and the substantial gaps in data, the pursuit of additional good-quality, large randomised clinical trials is not only justified but also essential to elucidate the efficacy and comparative benefits of microwave ablation in relation to various interventions for liver metastases. The current version of the review, in comparison to the previous one, incorporates two new trials in two additional microwave ablation comparisons: 1. in addition to conventional TACE versus conventional TACE alone and 2. versus radiofrequency ablation.

Effects of Different Recovery Positions on the Postpercutaneous Liver Biopsy Complications: A Metaanalysis

Objective: We aim to evaluate the effects of different recovery positions on the adverse events and the patient acceptability in those who underwent percutaneous liver biopsy (PLB). Methods: A literature search was conducted in the Cochrane Library, Embase, Scopus, PubMed, CNKI, Sinomed, and Wanfang databases. The time for the article extraction was until July 2020. The articles were screened by two independent researchers, together with the bias risk evaluation and data extraction. The RevMan 5.4 software was utilized for the metaanalysis. Results: Finally, two articles involving 180 subjects were eligible for this study. Metaanalysis showed that at T0, the alternation between right-side and combined position (CRP) would induce an elevation of post-PLB pain compared with the dorsal/supine position (SRP) [WMD = -2.00, 95% CI (-3.54, -0.47), p = 0.01]. There were no statistical differences in the postoperative pain among the CRP, SRP, and right-side position (RRP). The patient acceptability of SRP and RRP was higher than that of the CRP. Finally, two eligible studies were included, which showed no incidence of pneumothorax and abdominal bleeding. Conclusions: CRP would induce post-PLB pain at T0. SRP was the most acceptable position for the cases that underwent PLB. There were no statistical differences in the incidence of pneumothorax and abdominal bleeding. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020196633.

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.

Electrocoagulation for liver metastases

BACKGROUND

Primary liver tumours and liver metastases from colorectal carcinoma are two of the most common malignant tumours to affect the liver. The liver is second only to the lymph nodes as the most common site for metastatic disease. More than half of the people with metastatic liver disease will die from metastatic complications. Electrocoagulation by diathermy is a method used to destroy tumour tissue, using a high-frequency electric current generating high temperatures, applied locally with an electrode (needle, blade, or ball). The objective of this method is to destroy the tumour completely, if possible, in a single session. With the time, electrocoagulation by diathermy has been replaced by other techniques, but the evidence is unclear.

OBJECTIVES

To assess the beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention, versus no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, CINAHL, ClinicalTrials.gov, ICTRP, and FDA to October 2020.

SELECTION CRITERIA

We considered all randomised trials that assessed beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention, versus comparators, in people with liver metastases, regardless of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We assessed risk of bias of the included trial using predefined risk of bias domains, and presented the review results incorporating the certainty of the evidence using GRADE.

MAIN RESULTS

We included one randomised clinical trial with 306 participants (175 males; 131 females) who had undergone resection of the sigmoid colon, and who had five or more visible and palpable hepatic metastases. The diagnosis was confirmed by histological assessment (biopsy) and by carcinoembryonic antigen (CEA) level. The trial was conducted in Iraq. The age of participants ranged between 38 and 79 years. The participants were randomised to four different study groups. The liver metastases were biopsied and treated (only once) in three of the groups: 75 received electrocoagulation by diathermy alone, 76 received electrocoagulation plus allopurinol, 78 received electrocoagulation plus dimethyl sulphoxide. In the fourth intervention group, 77 participants functioning as controls received a vehicle solution of allopurinol 5 mL 4 x a day by mouth; the metastases were left untouched. The status of the liver and lungs was followed by ultrasound investigations, without the use of a contrast agent. Participants were followed for five years. The analyses are based on per-protocol data only analysing 223 participants. We judged the trial to be at high risk of bias. After excluding 'nonevaluable patients', the groups seemed comparable for baseline characteristics. Mortality due to disease spread at five-year follow-up was 98% in the electrocoagulation group (57/58 evaluable people); 87% in the electrocoagulation plus allopurinol group (46/53 evaluable people); 86% in the electrocoagulation plus dimethyl sulphoxide group (49/57 evaluable people); and 100% in the control group (55/55 evaluable people). We observed no difference in mortality between the electrocoagulation alone group versus the control group (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.94 to 1.03; 113 participants; very low-certainty evidence). We observed lower mortality in the electrocoagulation combined with allopurinol or dimethyl sulphoxide group versus the control group (RR 0.87, 95% CI 0.80 to 0.95; 165 participants; low-certainty evidence). We are very uncertain regarding post-operative deaths between the electrocoagulation alone group versus the control group (RR 1.03, 95% CI 0.07 to 16.12; 152 participants; very low-certainty evidence) and between the electrocoagulation combined with allopurinol or dimethyl sulphoxide groups versus the control group (RR 1.00, 95% CI 0.09 to 10.86; 231 participants; very low-certainty evidence). The trial authors did not report data on number of participants with other adverse events and complications, recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life. Data on failure to clear liver metastases were not provided for the control group. There was no information on funding or conflict of interest. We identified no ongoing trials.

AUTHORS' CONCLUSIONS

The evidence on the beneficial and harmful effects of electrocoagulation alone or in combination with allopurinol or dimethyl sulphoxide in people with liver metastases is insufficient, as it is based on one randomised clinical trial at low to very low certainty. It is very uncertain if there is a difference in all-cause mortality and post-operative mortality between electrocoagulation alone versus control. It is also uncertain if electrocoagulation in combination with allopurinol or dimethyl sulphoxide may result in a slight reduction of all-cause mortality in comparison with a vehicle solution of allopurinol (control). It is very uncertain if there is a difference in post-operative mortality between the electrocoagulation combined with allopurinol or dimethyl sulphoxide group versus control. Data on other adverse events and complications, failure to clear liver metastases or recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life were most lacking or insufficiently reported for analysis. Electrocoagulation by diathermy is no longer used in the described way, and this may explain the lack of further trials.

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.

MWA Versus RFA for Perivascular and Peribiliary CRLM: A Retrospective Patient- and Lesion-Based Analysis of Two Historical Cohorts

Purpose

To retrospectively analyse the safety and efficacy of radiofrequency ablation (RFA) versus microwave ablation (MWA) in the treatment of unresectable colorectal liver metastases (CRLM) in proximity to large vessels and/or major bile ducts.

Method and Materials

A database search was performed to include patients with unresectable histologically proven and/or ¹⁸F–FDG–PET avid CRLM who were treated with RFA or MWA between January 2001 and September 2014 in a single centre. All lesions that were considered to have a peribiliary and/or perivascular location were included. Univariate logistic regression analysis was performed to assess the distribution of patient, tumour and procedure characteristics. Multivariate logistic regression was used to correct for potential confounders.

Results

Two hundred and forty-three patients with 774 unresectable CRLM were ablated. One hundred and twenty-two patients (78 males; 44 females) had at least one perivascular or peribiliary lesion (n = 199). Primary efficacy rate of RFA was superior to MWA after 3 and 12 months of follow-up (P = 0.010 and P = 0.022); however, after multivariate analysis this difference was non-significant at 12 months (P = 0.078) and vanished after repeat ablations (P = 0.39). More CTCAE grade III complications occurred after MWA versus RFA (18.8 vs. 7.9 %; P = 0.094); biliary complications were especially common after peribiliary MWA (P = 0.002).

Conclusion

For perivascular CRLM, RFA and MWA are both safe treatment options that appear equally effective. For peribiliary CRLM, MWA has a higher complication rate than RFA, with similar efficacy. Based on these results, it is advised to use RFA for lesions in the proximity of major bile ducts.

Hepatectomy vs radiofrequency ablation for colorectal liver metastasis: A propensity score analysis

AIM: To compare outcomes from radiofrequency ablation (RFA) and hepatectomy for treatment of colorectal liver metastasis (CRLM).

METHODS: From January 2000 to December 2009, 408 patients underwent curative intent treatment for CRLM. We excluded patients using the criteria: size of CRLM > 3 cm, number of CRLM ≥ 5, percutaneous RFA, follow-up period < 12 mo, double primary cancer, or treatment with both RFA and hepatectomy. We matched 51 patients who underwent RFA with 102 patients who underwent hepatectomy by propensity scores.

RESULTS: The median follow-up period was 45 mo (range, 12 mo to 158 mo). Hepatic recurrence was more frequent in the RFA than the hepatectomy group (P = 0.021) although extrahepatic recurrence curves were similar (P = 0.716). Survival curves of hepatectomy group were better than that of RFA for multiple, large (> 2 cm) CRLM (P = 0.034). However, survival curves were similar for single or small (≤ 2 cm) CRLM (P = 0.714, P = 0.740).

CONCLUSION: Hepatectomy is better than RFA for the treatment of CRLM. However, RFA might be suitable for selected patients with single, small (≤ 2 cm) CRLM.

Small for size liver remnant following resection: prevention and management

In the latest decades an important change was registered in liver surgery, however the management of liver cirrhosis or small size hepatic remnant still remains a challenge. Currently post-hepatectomy liver failure (PLF) is the major cause of death after liver resection often associated with sepsis and ischemia-reperfusion injury (IRI). ''Small-for-size'' syndrome (SFSS) and PFL have similar mechanism presenting reduction of liver mass and portal hyper flow beyond a certain threshold. Few methods are described to prevent both syndromes, in the preoperative, perioperative and postoperative stages. Additionally to portal vein embolization (PVE), radiological examinations (mainly CT and/or MRI), and more recently 3D computed tomography are fundamental to quantify the liver volume (LV) at a preoperative stage. During surgery, in order to limit parenchymal damage and optimize regenerative capacity, some hepatoprotective measures may be employed, among them: intermittent portal clamping and hypothermic liver preservation. Regarding the treatment, since PLF is a quite complex disease, it is required a multi-disciplinary approach, where it management must be undertaken in conjunction with critical care, hepatology, microbiology and radiology services. The size of the liver cannot be considered the main variable in the development of liver dysfunction after extended hepatectomies. Additional characteristics should be taken into account, such as: the future liver remnant; the portal blood flow and pressure and the exploration of the potential effects of regeneration preconditioning are all promising strategies that could help to expand the indications and increase the safety of liver surgery.

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.