The clinical utility and outcomes of microwave ablation for colorectal cancer liver metastases

Ablative techniques in colorectal liver metastases: A systematic review, descriptive summary of practice, and recommendations for optimal data reporting

BACKGROUND

Radiofrequency Ablation (RFA) and Microwave Ablation (MWA) are alternative treatments for colorectal liver metastasis (CRLM) patients that are unsuitable for resection. However, consensus is lacking regarding selection criteria, tumour characteristics, ablation technique delivery, and device settings. This study aims to summarise current evidence to inform future prospective studies.

METHODS

A systematic review was conducted following PRISMA guidelines. Studies assessing RFA and MWA treatment of CRLM were identified in Medline, Embase, Web of Science and the Cochrane database of systematic reviews, from inception until 31st August 2024.

RESULTS

Fifty-two studies were included (retrospective cohort n = 45, prospective cohort n = 5, non-randomized comparative studies n = 2). Fifty-four inclusion criteria were used across 45 studies and were not stated in 7 studies. Tumours varied in mean number [1-8] and diameter (1.54-4.35 cm). Neoadjuvant chemotherapy use (10-100 % of patients), ablation delivery approach (open n = 4, laparoscopic n = 11, percutaneous n = 26, mixed n = 5), anaesthetic mode (GA n = 18, LA n = 11, mixed n = 2) and delivering clinician (radiologist n = 11, surgeon n = 16, both n = 1) all varied. Thirty-two studies lacked complete ablation device settings. Six studies followed a standardized ablation algorithm and 14 studies had specific settings. Five-year survival ranged from 0 to 69.7 % for ablation.

CONCLUSIONS

There is significant heterogeneity in the reporting of study design, patient selection, and ablation techniques for CRLM. The lack of standardized approaches and inconsistent reporting of methodology and outcomes make it challenging to determine the optimal ablative treatment for CRLM. We recommend that future research should focus on clearly defining selection and treatment criteria, as well as treatment delivery.

Comparison of the Efficiency of Radiofrequency and Microwave Ablation Methods in the Treatment of Benign Thyroid Nodules

RATIONALE AND OBJECTIVES

To compare the efficacy of two thermal ablation techniques (radiofrequency vs microwave ablation) in the treatment of benign thyroid nodules.

MATERIALS AND METHODS

A total of 80 patients with 80 nodules underwent thermal ablation of thyroid nodules with either radiofrequency ablation (RFA) (23 females and 14 males; mean age 41 ± 9years) or microwave ablation (MWA) (28 females and 15 males; mean age 45 ± 11years). Ultrasound assessments were made at the 1st, 3rd, 6th, and 12th months after the ablation procedure.

RESULTS

The mean initial volume of the nodules (RFA: 15.6 mL [min 2.5-max 74]; MWA: 40 mL [min 2-max 205]) was statistically significantly different (P < .001). The following were the volume reduction rates of nodules at 1, 3, 6, and 12months, respectively: after RFA: 46.8 ± 13.5%, 62.9 ± 13.6%, 71.6 ± 11.9%, and 77.9 ± 10.3%. After MWA: 38.7 ± 12.5%, 54 ± 15.3%, 59.6 ± 12.5%, and 65 ± 11.3%. For all months, volume reduction rates in the RFA group were significantly higher than those in the MWA group (P < .05). One patient treated by RFA reported an abscess formation and another patient treated by RFA had a self-limiting hematoma, who recovered without any further treatment. Also, in the MWA group, one patient had abscess formation and another patient had transient recurrent nerve paralysis, who recovered with appropriate treatment.

CONCLUSION

Both methods are effective in treating benign thyroid nodules; however, RFA provides a better volume reduction.

Colorectal Liver Metastases: A Literature Review of Viable Surgical Options with a Special Focus on Microwave Liver Thermal Ablation and Mini-Invasive Approach

Colorectal cancer (CRC) is the third most common tumor worldwide and it is characterized in 20-30% of cases by liver involvement, which strongly affects the long-term patient outcome. There are many available therapies for liver colorectal metastases (CRLMs); the current standard of care is represented by liver resection, and when feasible, associated with systemic chemotherapy. Microwave thermal ablation (MWA) is a viable option in unresectable patients or to achieve treatment with a parenchymal spearing approach. A literature review was performed for studies published between January 2000 and July 2022 through a database search using PUBMED/Medline and the Cochrane Collaboration Library with the following MeSH search terms and keywords: microwave, ablation, liver metastases, colorectal neoplasm, and colon liver rectal metastases. The recurrence rate and overall patients' survival were evaluated, showing that laparoscopic MWA is safe and effective to treat CRLMs when resection is not feasible, or a major hepatectomy in fragile patients is necessary. Considering the low morbidity of this procedure, it is a viable option to treat patients with recurrent diseases in the era of effective chemotherapy and multimodal treatments.

[Colorectal cancer liver metastases: current state of the problem, priority treatment approaches]

The review is devoted to the world trends in epidemiology of colorectal cancer and treatment of colorectal cancer liver metastases. The authors analyze the effectiveness of traditional (resection) and modern minimally invasive methods of local destruction (radiofrequency thermoablation, microwave ablation, cryoablation), stereotactic radiotherapy, radiosurgery, targeted therapy and endovascular techniques (chemoinfusion, chemoembolization, radioembolization). It was emphasized that searching for new chemotherapeutic and targeted drugs is one of the reserve ways to improve treatment outcomes in patients with potentially resectable colorectal cancer liver metastases. The possibilities and prospects of liver transplantation as a priority treatment strategy for patients with unresectable bilobar colorectal cancer liver metastases are highlighted.

Microwave Ablation for Colorectal Liver Metastases: A Systematic Review and Pooled Oncological Analyses

Simple Summary

Liver resection for colorectal liver metastases (CRLM) represents the best curative option; however, few patients are candidates for surgery. Microwave ablation (MWA) can be a valid alternative in selected patients. This systematic review reports the oncological results of MWA for CRLM. The literature available on the Web was analyzed for reports concerning MWA for resectable CRLM, published before January 2021. Finally, 12 papers concerning MWA complications, recurrence-free (RF) cases, patients free from local recurrence (FFLR), and overall survival rates (OS) were selected. Global RF rates at 1, 3, and 5 years were 65.1%, 44.6%, and 34.3%, respectively. Global FFLR at 3, 6, and 12 months were 96.3%, 89.6%, and 83.7%, respectively. Global OS rates at 1, 3, and 5 years were 86.7%, 59.6%, and 44.8%, respectively. A better FFLR was achieved with an MWA surgical approach at 3, 6, and 12 months, with 97.1%, 92.7%, and 88.6%, respectively. Surgical MWA for CRLM smaller than 3 cm was a safe and valid option. MWA can be entered as part of the flowchart decision of CRLM curative treatment, especially for use in the parenchyma-sparing strategy and as a complement to surgery.

Abstract

(1) Background: colorectal liver metastases (CRLM) are the most common extra-lymphatic metastases in colorectal cancer; however, few patients are fit for curative surgery. Microwave ablation (MWA) showed promising outcomes in this cohort of patients. This systematic review and pooled analysis aimed to analyze the oncological results of MWA for CRLM. (2) Methods: Following PRISMA guidelines, PubMed, Scopus, EMBASE, Google Scholar, Science Direct, and the Wiley Online Library databases were searched for reports published before January 2021. We included papers assessing MWA, treating resectable CRLM with curative intention. We evaluated the reported MWA-related complications and oncological outcomes as being recurrence-free (RF), free from local recurrence (FFLR), and overall survival rates (OS). (3) Results: Twelve out of 4822 papers (395 patients) were finally included. Global RF rates at 1, 3, and 5 years were 65.1%, 44.6%, and 34.3%, respectively. Global FFLR rates at 3, 6, and 12 months were 96.3%, 89.6%, and 83.7%, respectively. Global OS at 1, 3, and 5 years were 86.7%, 59.6%, and 44.8%, respectively. A better FFLR was reached using the MWA surgical approach at 3, 6, and 12 months, with reported rates of 97.1%, 92.7%, and 88.6%, respectively. (4) Conclusions: Surgical MWA treatment for CRLM smaller than 3 cm is a safe and valid option. This approach can be safely included for selected patients in the curative intent approaches to treating CRLM.

Local Treatments in the Unresectable Patient with Colorectal Cancer Metastasis: A Review from the Point of View of the Medical Oncologist

For patients with isolated liver metastases from colorectal cancer who are not candidates for potentially curative resections, non-surgical local treatments may be useful. Non-surgical local treatments are classified according to how the treatment is administered. Local treatments are applied directly on hepatic parenchyma, such as radiofrequency, microwave hyperthermia and cryotherapy. Locoregional therapies are delivered through the hepatic artery, such as chemoinfusion, chemoembolization or selective internal radiation with Yttrium 90 radioembolization. The purpose of this review is to describe the different interventional therapies that are available for these patients in routine clinical practice, the most important clinical trials that have tried to demonstrate the effectiveness of each therapy and recommendations from principal medical oncologic societies.

Radiofrequency versus microwave ablation for intraoperative treatment of colorectal liver metastases

INTRODUCTION

Intraoperative radiofrequency ablation (RFA) and the newer technique of microwave ablation (MWA) can both be of additional value in parenchyma preserving surgical treatment of colorectal liver metastases (CRLM). MWA is less influenced by the heat-sink effect of surrounding vessels and can generate more heat in less time but RFA is still widely used. True comparing studies are scarce.

METHODS

This single centre retrospective cohort study analyzed patients who underwent ultrasound guided intraoperative ablation as a part of the surgical treatment of CRLM between 2013 and 2018. In September 2015, MWA was substituted for RFA. Outcomes included unsuccessful ablation rates at 1-year postoperative, 30-days major complication rates, progression free survival (PFS) and overall survival (OS). Logistic regression models were used for univariable and multivariable analyses to identify predictors of unsuccessful ablation.

RESULTS

Forty-one patients underwent RFA of 98 lesions (median 2) and 79 patients underwent MWA of 193 lesions (median 2). The median diameter of the ablated lesions was 9 mm for both RFA and MWA. Unsuccessful ablation was observed in 7 metastases (7.1%) after RFA and 14 metastases (7.3%) after MWA (p = 1.000). Complications requiring re-intervention were observed after 8 procedures, 2 complications in the RFA group (4.9%) versus 6 complications in the MWA group (7.6%, p = 0.714), of which 6 were liver-related. Ninety-day mortality did not occur. Ablation technique was not associated with unsuccessful ablations. CRLM size was associated with unsuccessful ablation in the per lesion analysis (p < 0.001).

CONCLUSION

Intraoperative RFA and MWA were equally effective for treatment of small CRLM.

Recurrence and survival following microwave, radiofrequency ablation, and hepatic resection of colorectal liver metastases: A systematic review and network meta-analysis

BACKGROUND

Gold standard for colorectal liver metastases (CRLM) remains hepatic resection (HR). However, patients with severe comorbidities, unresectable or deep-situated resectable CRLM are candidates for ablation. The aim of the study was to compare recurrence rate and survival benefit of the microwave ablation (MWA), radiofrequency ablation (RFA) and HR by conducting the first network meta-analysis.

DATA SOURCES

Systematic search of the literature was conducted in the electronic databases. Both updated traditional and network meta-analyses were conducted and the results were compared between them.

RESULTS

HR cohort demonstrated significantly less local recurrence rate and better 3- and 5-year disease-free (DFS) and overall survival (OS) compared to MWA and RFA cohorts. HR cohort included significantly younger patients and with significantly lower preoperative carcinoembryonic antigen (CEA) by 10.28 ng/mL compared to RFA cohort. Subgroup analysis of local recurrence and OS of solitary and ≤ 3 cm CRLMs did not demonstrate any discrepancies when compared with the whole sample.

CONCLUSIONS

For resectable CRLM the treatment of choice still remains HR. MWA and RFA can be used as a single or adjunct treatment in patients with unresectable CRLM and/or prohibitive comorbidities.

Long-term outcome for colorectal liver metastases: combining hepatectomy with intraoperative ultrasound guided open microwave ablation versus hepatectomy alone

OBJECTIVE

To compare the long-term outcome of combining hepatectomy with intraoperative ultrasound (IOUS)-guided open microwave ablation (MWA) versus hepatectomy alone in patients with colorectal cancer liver metastases (CRLM).

METHOD

A retrospective analysis of patients with CRLM who underwent hepatectomy alone (HT group; 380 patients) or hepatectomy combined with IOUS-guided open MWA (HT + MWA group; 57 patients) from April 2002 to September 2018 was conducted at our center. A propensity score-matched (PSM) analysis was used to reduce data bias between the two groups.

RESULTS

The overall survival (OS) and disease-free survival (DFS) were not significantly different between the two groups after matching. Although intrahepatic recurrence was more frequent in the HT + MWA group in both the whole and matched cohort, the two groups exhibited similar rates of extrahepatic recurrence as well as concomitant intra- and extrahepatic recurrence. A higher number of CRLM (>3), larger maximum-size and absence of response to induction chemotherapy were independent risk factors for OS.

CONCLUSION

The oncological outcomes of hepatectomy combined with intraoperative open ablation was not significantly different to hepatectomy alone and should be considered as a safe and fair option for patients with difficultly resectable CRLM.

Optimizing Loco Regional Management of Oligometastatic Colorectal Cancer: Technical Aspects and Biomarkers, Two Sides of the Same Coin

Colorectal cancer (CRC) is the third most common cancer worldwide and has a high rate of metastatic disease which is the main cause of CRC-related death. Oligometastatic disease is a clinical condition recently included in ESMO guidelines that can benefit from a more aggressive locoregional approach. This review focuses the attention on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic locoregional strategies drawn from the current literature and consensus conferences. The different percutaneous therapies (radiofrequency ablation, microwave ablation, irreversible electroporation) as well as trans-arterial approaches (chemoembolization and radioembolization) are discussed. Ablation margins, the choice of the imaging guidance as well as characteristics of the different ablation techniques and other technical aspects are analyzed. A specific attention is then paid to the increasing role of biomarkers (in particular molecular profiling) and their role in the selection of the proper treatment for the right patient. In conclusion, in this review an up-to-date state of the art of the application of locoregional treatments on CRLM is provided, highlighting both technical aspects and the role of biomarkers, two sides of the same coin.

Long-term results of percutaneous microwave ablation for colorectal liver metastases

BACKGROUND

Radiofrequency ablation (RFA) has been used for therapy of colorectal liver metastases (CRLMs) several years, with considerable data confirming its safety and efficacy. However, there are few studies focusing on the long-term results of percrtaneous microwave ablation (PMWA) for CRLMs. The aim of this study was to evaluate the long-term survival and prognostic factors in patients with CRLMs undergoing PMWA.

METHODS

We retrospectively analyzed treatment and survival parameters of 210 patients with CRLMs who had received PMWA in a single center from January 2010 to December 2017. Prognostic factors for survival were evaluated by means of univariate and multivariate analyses.

RESULTS

The median follow-up time after PMWA was 48 months. The median overall survival (OS) time were 40.0 months (95% CI, 31.4 to 48.5 months), with 1-, 2, 3-, 4, and 5-year cumulative survival rates of 98.6%, 73.3%, 53.3%, 42.2%, and 32.9%, respectively. Tumor number (P = 0.004; HR: 1.838; CI: 1.213- 2.784), main tumor size (P = 0.017; HR: 1.631; CI: 1.093- 2.436), and serum CEA level (P = 0.032; HR: 1.559; CI: 1.039-2.340) were found as independent predictors of OS. The median OS time for patients with resectable lesions was 60.91 months (95% CI, 51.36 to 70.47 months), with 5-year cumulative survival rates of 53.5%.

CONCLUSION

PMWA is a safe and effective treatment for CRLMs, with a favorable long-term outcome. Multiple lesions, main tumor diameter>3 cm, and serum CEA >30 ng/ml have a significant negative effect on OS.

Comparison between ultrasound-guided percutaneous radiofrequency and microwave ablation in benign thyroid nodules

Objective

The purpose of this study was to compare the efficacy and safety of radiofrequency ablation (RFA) and microwave ablation (MWA) for the treatment of benign thyroid nodules (BTNs).

Methods

Patients with BTNs were treated in our hospital, including 72 patients treated with RFA and 100 patients treated with MWA from June 2016 to March 2019. The volume reduction rates (VRRs), thyroid function, clinical status, and complications were compared at each postoperative duration to evaluate the efficacy and safety of the two modalities.

Results

The mean VRRs of the RFA group vs. the MWA group at 1, 3, 6, and 12 months were 22.7±13.4% vs. 24.0±16.1% (P = 0.681), 56.1±19.5% vs. 54.8±22.8% (P = 0.788), 77.9±21.0% vs. 68.7±19.1% (P = 0.038), and 85.4±18.9% vs. 75.8±19.4% (P = 0.029), respectively. There was no significant difference in the VRRs between the two treatments at 1 and 3 months and the RFA group achieved higher VRRs than MWA group at 6 and 12 months. Moreover, the symptom and cosmetic scores decreased significantly in both groups and all patients succeeded in preserving thyroid function. Of the total patients, 2.8% in the RFA group and 4% in the MWA group experienced voice changes after undergoing thyroid ablation, and one patient in the RFA group had intraoperative hemorrhage of about 10 mL.

Conclusions

RFA and MWA are both effective and safe techniques for treating BTNs. Higher VRRs were observed at the 6- and 12-month follow-ups in the RFA group.

Systematic review and meta-analysis of local ablative therapies for resectable colorectal liver metastases

INTRODUCTION

Local ablative therapies (LAT) have shown positive but heterogenous outcomes in the treatment of colorectal liver metastases (CRLM). The aim of this systematic review is to evaluate LAT and compare them with surgical resection.

METHODS

In accordance with PRISMA guidelines, Medline, EMBASE, Cochrane and Web of Science databases were searched for reports published before January 2019. We included papers assessing radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA) and electroporation (IRE) treating resectable CRLM with curative intention. We evaluated LAT related complications and oncological outcomes as tumour progression (LTP), disease-free survival (DFS) and overall survival (OS).

RESULTS

The literature search yielded 6767 records; 20 papers (860 patients) were included. No included studies related mortality with LAT. Median adverse events percentage was 7%: (8% RFA;7% MWA). Median 3y-DFS was 32% (24% RFA; 60% MWA); 5y-DFS was 27%: (18% RFA; 38.5% MWA). Median 3y-OS was 59% (60% RFA; 70% MWA; 34% CA), 5y-OS was 44.5% (43% RFA; 55% MWA; 20% CA). Surgical resection showed decreased LTP, improved DFS and OS than those reported with LAT, with RFA accounting for reduced 1y-DFS (RR 0.83, 95%CI 0.71-0.98), 3y-DFS (RR 0.5, 95%CI 0.33-0.76), 5y-DFS (RR 0.53, 95%CI 0.28-0.98) and 5y-OS (RR 0.76, 95%CI 0.58-0.98) in comparison with surgical resection.

CONCLUSIONS

Low quality evidence suggests that both RFA and MWA seem superior to CA. MWA presents similar adverse events when compared to RFA with a possible increase in DFS and OS. Surgical resection still seems to provide superior DFS and OS in comparison with LAT.

The efficacy of microwave ablation versus liver resection in the treatment of hepatocellular carcinoma and liver metastases: A systematic review and meta-analysis

BACKGROUND

Microwave ablation (MWA) is an important method in the treatment of liver cancer. This systematic review compared MWA with liver resection (LR) for liver cancer treatment. In recent years, the MWA has been also reported to play an important role. Studies comparing MWA and LR are lacking. This study aims to compare the efficacy of MWA and LR in the treatment of hepatocellular carcinoma (HCC).

METHODS

A systematic search of PubMed, Embase, Cochrane Library and Web of Science up to April 1, 2019 was conducted for relevant studies that compared the efficacy of MWA and LR in the treatment of HCC. The primary outcomes were local tumor recurrence (LTR) and overall survival (OS) of patients. The secondary outcomes included disease free survival (DFS), extrahepatic metastasis, intrahepatic de novo lesions, length of stay, complications, intraoperative blood loss and operative time.

RESULTS

A total of 16 studies including 2622 patients were identified. Incidence of LTR was significantly higher in patients with MWA than LR, with a pooled OR of 2.69 (95% CI 1.33-5.41; P = 0.006). No significant difference in 1-year OS was found. However, patients with MWA experienced higher 3- and 5-year OS, with pooled ORs of 1.40 (95% CI 1.07-1.84; P = 0.01) and 1.41 (95% CI 1.10-1.80; P = 0.007) respectively. In secondary measures, the 1- and 3-year DFS were significantly higher in patients with MWA. However, no significant difference of 5-year DFS was observed. In addition, lower incidence of complications, less intraoperative blood loss and shorter operative time and shorter length of stay were observed in MWA.

CONCLUSIONS

Though MWA may lead to higher incidence of recurrence, it may be an effective and safe alternative in patients with HCC or liver metastases. MWA may have benefits in patients' survival and safety. Randomized studies should be performed to determine the target population that benefits most from MWA in the future.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

How to increase the resectability of initially unresectable colorectal liver metastases: A surgical perspective

Although surgical resection is the only treatment of choice that can offer prolonged survival and a chance of cure in patients with colorectal liver metastases (CRLM), nearly 80% of patients are deemed to be unresectable at the time of diagnosis. Considerable efforts have been made to overcome this initial unresectability, including expanding the indication of surgery, the advent of conversion chemotherapy, and development and modification of specific surgical techniques, regulated under multidisciplinary approaches. In terms of specific surgical techniques, portal vein ligation/embolization can increase the volume of future liver remnant and thereby reduce the risk of hepatic insufficiency and death after major hepatectomy. For multiple bilobar CRLM that were traditionally considered unresectable even with preoperative chemotherapy and portal vein embolization, two-stage hepatectomy was introduced and has been adopted worldwide with acceptable short- and long-term outcomes. Recently, ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) was reported as a novel variant of two-stage hepatectomy. Although issues regarding safety remain unresolved, rapid future liver remnant hypertrophy and subsequent shorter intervals between the two stages lead to a higher feasibility rate, reaching 98%. In addition, adding radiofrequency ablation and vascular resection and reconstruction techniques can allow expansion of the pool of patients with CRLM who are candidates for liver resection and thus a cure. In this review, we discuss specific techniques that may expand the criteria for resectability in patients with initially unresectable CRLM.

Late Gadolinium Hyperintensity of Suspected Colorectal Liver Metastases on Gadofosveset-Enhanced Magnetic Resonance Imaging: A Predictor of Benignity and a Potential Problem-Solving Tool

PURPOSE

Late gadolinium hyperintensity (LGH) is sometimes seen in colorectal liver metastasis (CRLM) and represents a significant diagnostic pitfall due to overlap with LGH in benign hemangiomas; therefore, the objective of this study was to determine the prevalence of LGH and the ability of LGH to differentiate between CRLM and benign lesions with intravascular (gadofosveset) vs extracellular contrast agents (gadobutrol).

METHODS

Patients with known colorectal cancer and suspected liver lesions were prospectively recruited into this institutional review board-approved, single institution study and received magnetic resonance imaging of the liver with gadofosveset and gadobutrol. The prevalence of LGH for CRLMs and solid benign lesions was determined. Receiver operating characteristics curves were determined for the presence of LGH as a predictor of benignity. The utility of LGH to differentiate between CRLM and solid benign lesions using gadofosveset vs gadobutrol was compared using the generalized estimating equation.

RESULTS

Twenty-five patients with 131 solid focal liver lesions were recruited. The prevalence of LGH of CRLMs was 11.2% (95% confidence interval [CI]: 0.5%-21.8%) with gadofosveset vs 63.7% (95% CI: 45.7%-81.7%) with gadobutrol. The area under the receiver operating characteristic curve for the presence of LGH as a predictor of benignity was 0.86 using gadofosveset vs 0.75 using gadobutrol. Both LGH (P = .003) and the interaction of contrast agent and LGH (P = .003) statistically significantly differentiated CRLM from benign lesions.

CONCLUSION

LGH is more common with extracellular than with intravascular contrast agents and is statistically significantly associated with benign lesions rather than metastases.

Microwave ablation compared with hepatic resection for the treatment of hepatocellular carcinoma and liver metastases: a systematic review and meta-analysis

Background

Hepatic resection (HR) is the gold standard liver cancer treatment, but few patients are eligible due to comorbidities or tumor location. Microwave ablation (MWA) is an important complementary liver cancer treatment to HR. This systematic review compared MWA with HR for liver cancer treatment.

Methods

A systematic search of MEDLINE, EMBASE, and CENTRAL was conducted for randomized and observational studies published from 2006 onwards. The primary outcome was local tumor recurrence (LTR), and a random effects model was used for meta-analyses.

Results

Of the 1845 studies identified, 1 randomized and 15 observational studies met the inclusion criteria. LTR was significantly increased with MWA versus HR (risk ratio (RR) = 2.49; P = 0.016). In secondary measures, HR provided significantly higher 3- and 5-year overall survival (RR = 0.94; P = 0.03 and RR = 0.88; P = 0.01, respectively) and 3-year disease-free survival (RR = 0.78; P = 0.009). MWA exhibited significantly shorter length of stay (weighted mean difference (WMD) = − 6.16 days; P < 0.001) and operative time (WMD = − 58.69 min; P < 0.001), less intraoperative blood loss (WMD = − 189.09 mL; P = 0.006), and fewer complications than HR (RR = 0.31; P < 0.001). When MWA was combined with HR and compared with either modality alone, complications and blood loss were significantly lower with the combination treatment; however, there were no differences in other outcomes. Subgroup and sensitivity analyses were generally aligned with the main results.

Conclusions

MWA can be an effective and safe alternative to HR in patients/tumors that are not amenable to resection. More randomized and economic studies should be performed that compare the two treatments, especially to determine the target population that benefits most from MWA.

Electronic supplementary material

The online version of this article (10.1186/s12957-019-1632-6) contains supplementary material, which is available to authorized users.

Long-term survival after percutaneous irreversible electroporation of inoperable colorectal liver metastases

Background

For colorectal liver metastases (CRLM) that are not amenable to surgery or thermal ablation, irreversible electroporation (IRE) is a novel local treatment modality and additional option.

Methods

This study is a retrospective long-term follow-up of patients with CRLM who underwent IRE as salvage treatment.

Results

Of the 24 included patients, 18 (75.0%) were male, and the median age was 57 (range: 28-75) years. The mean time elapsed from diagnosis to IRE was 37.9±37.3 months. Mean overall survival was 26.5 months after IRE (range: 2.5-69.2 months) and 58.1 months after diagnosis (range: 14.8-180.1 months). One-, three-, and five-year survival rates after initial diagnosis were 100.0%, 79.2%, and 41.2%; after IRE, the respective survival rates were 79.1%, 25.0%, and 8.3%. There were no statistically significant differences detected in survival after IRE with respect to gender, age, T- or N-stage at the time of diagnosis, size of metastases subject to IRE, number of hepatic lesions, or time elapsed between IRE and diagnosis.

Conclusion

For nonresectable CRLM, long-term survival data emphasize the value of IRE as a new minimally invasive local therapeutic approach in multimodal palliative treatment, which is currently limited to systemic or regional therapies in this setting.

CT-guided navigated microwave ablation (MWA) of an unfavorable located breast cancer metastasis in liver segment I

For percutaneous minimally-invasive local ablation therapies of malignant lesions within the liver computed tomography (CT) fluoroscopy or ultrasound (US) can be applied for the positioning of ablation probes. However, lesions in liver segment I and in the upper part of liver segment VIII are difficult to reach with CT fluoroscopy and US guidance even for experienced interventionalists as steep and transcostal access paths may be needed. In addition, there is always the risk to lacerate crucial vessels near the liver hilus. We report on the use of a CT-based stereotactic navigation system (CAS-One, CAScination AG, Bern, Switzerland) for the precise positioning of the ablation probe to perform a percutaneous stereotactic image-guided microwave ablation of a breast cancer liver metastasis in liver segment I that was unreachable with conventional CT or US guidance. Based on the initial planning scan and image-to-patient registration a precise positioning of the probe was possible sparing vital structures like the directly adjacent vulnerable vessels. The ablation was performed without complications fully covering the metastatic lesion with the ablation zone. To this day, there was no recurring tumor 18 months after the intervention.