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

Optimal treatment strategies for borderline resectable liver metastases from colorectal cancer

BACKGROUND

Traditionally, colorectal liver metastases (CRLMs) are divided into "initially resectable" and "initially unresectable." The terminology "borderline resectable" continues to be elusive without any common consensus or definition. This narrative review aims to decode the conundrum of "borderline resectable CRLM (BR-CRLM)" and to discuss optimal treatment strategies.

METHODS

A comprehensive review was performed using Medline/PubMed and Web of Science databases with a search period ending on January 1, 2024. Using PubMed, the terms "CRLM," "BR-CRLM," and "management of BR-CRLM" were searched.

RESULTS

The 2016 European Society for Medical Oncology guidelines defined the term "resectability" in CRLM using the "technical (surgical) criteria" and the "oncologically criteria." These 2 criteria form the basis of defining BR-CRLM. Thus, BR-CRLM can be either technically easy but with unfavorable oncologically criteria or technically difficult with favorable oncologically criteria. Although defining BR-CRLM by incorporating both these criteria seems to be the most logical way forward, there is currently a lot of heterogeneity in the literature. It is generally agreed upon that some form of chemotherapy needs to be administered in BR-CRLM before embarking on surgery. Conversion chemotherapy is used in patients with BR-CRLM in which there is a possibility of resection after effective downsizing. Along with improved effective chemotherapy, great strides have been made in pushing the limits of surgery to achieve resectability in this subset of patients.

CONCLUSION

Advanced surgical techniques and locoregional liver-directed therapies coupled with perioperative chemotherapy with or without targeted therapy have made long-term survival benefit, a reality in patients with BR-CRLM. Thus, the time has come to recognize "BR-CRLM" as a distinct entity.

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Debulking Hepatectomy for Colorectal Liver Metastasis Conveys Survival Benefit

(1) Background: Despite advances in surgical technique and systemic chemotherapy, some patients with multifocal, bilobar colorectal liver metastases (CRLM) remain unresectable. These patients may benefit from surgical debulking of liver tumors in combination with chemotherapy compared to chemotherapy alone. (2) Methods: A retrospective study including patients evaluated for curative intent resection of CRLM was performed. Patients were divided into three groups: those who underwent liver resection with recurrence within 6 months (subtotal debulked, SD), those who had the first stage only of a two-stage hepatectomy (partially debulked, PD), and those never debulked (ND). Kaplan-Meier survival curves and log-rank test were performed to assess the median survival of each group. (3) Results: 174 patients underwent liver resection, and 34 patients recurred within 6 months. Of the patients planned for two-stage hepatectomy, 35 underwent the first stage only. Thirty-two patients were never resected. Median survival of the SD, PD, and ND groups was 31 months, 31 months, and 19.5 months, respectively (p = 0.012); (4) Conclusions: Patients who underwent a debulking of CRLM demonstrated a survival benefit compared to patients who did not undergo any surgical resection. This study provides support for the evaluation of intentional debulking versus palliative chemotherapy alone in a randomized trial.

Trends and overall survival after combined liver resection and thermal ablation of colorectal liver metastases: a nationwide population-based propensity score-matched study

BACKGROUND

In colorectal liver metastases (CRLM) patients, combination of liver resection and ablation permit a more parenchymal-sparing approach. This study assessed trends in use of combined resection and ablation, outcomes, and overall survival (OS).

METHODS

This population-based study included all CRLM patients who underwent liver resection between 2014 and 2022. To assess OS, data was linked to two databases containing date of death for patients treated between 2014 and 2018. Hospital variation in the use of combined minor liver resection and ablation versus major liver resection alone in patients with 2-3 CRLM and ≤3 cm was assessed. Propensity score matching (PSM) was applied to evaluate outcomes.

RESULTS

This study included 3593 patients, of whom 1336 (37.2%) underwent combined resection and ablation. Combined resection increased from 31.7% in 2014 to 47.9% in 2022. Significant hospital variation (range 5.9-53.8%) was observed in the use of combined minor liver resection and ablation. PSM resulted in 1005 patients in each group. Major morbidity was not different (11.6% vs. 5%, P = 1.00). Liver failure occurred less often after combined resection and ablation (1.9% vs. 0.6%, P = 0.017). Five-year OS rates were not different (39.3% vs. 33.9%, P = 0.145).

CONCLUSION

Combined resection and ablation should be available and considered as an alternative to resection alone in any patient with multiple metastases.

Combined ablation and resection (CARe) for resectable colorectal cancer liver Metastases-A propensity score matching study

BACKGROUND

The efficacy of combining ablation and resection (CARe) in treating unresectable colorectal cancer liver metastases (CRLM) was well established. This study aimed to investigate the surgical and oncological outcomes of CARe strategy focusing on initially resectable CRLM.

PATIENTS AND METHODS

A total of 971 patients with resectable CRLM from a retrospective database of 1414 CRLM patients were enrolled, including 120 in the CARe group and 851 in the hepatectomy alone group. Short- and long-term outcomes were compared between groups using propensity score matching analysis.

RESULTS

After propensity score matching, 96 matched pairs of patients from each group were included. General characteristics of primary tumour and liver metastases were not statistically different between the CARe group and hepatectomy alone group. Disease-free survival (p = 0.257), intrahepatic recurrence-free survival (p = 0.329), and overall survival (p = 0.358) were similar between the two groups. Patients in CARe group had significantly reduced rate of major hepatectomy (5.2% vs. 21.9%, p = 0.001), lower incidence of postoperative hepatic insufficiency (0.0% vs. 5.2%, p = 0.023), and shortened postoperative hospital stay (7 d vs. 8 d, p = 0.019). Multivariate analysis showed that surgical approach did not affect oncologic outcome; liver metastasis with diameter >3 cm was an independent prognostic factor for hepatic recurrence-free and disease-free survival, and RAS status and lymph node metastasis at the primary site were independent prognostic factors for overall survival.

CONCLUSION

For patients with resectable CRLM, CARe may be a better treatment strategy than hepatectomy alone, as it could avoid major hepatectomy and get better surgical outcomes, while providing the similar oncologic results.

Combining Radiofrequency Ablation with Hepatic Resection for Liver-Only Colorectal Metastases: A Propensity-Score Based Analysis of Long-Term Outcomes

BACKGROUND

Combining liver resection (LR) with radiofrequency ablation (RFA) is nowadays an accepted option for treating colorectal liver metastases (CRLMs), but the number of lesions ablated is regularly described as a recurrence risk factor. In this study, we report our experience and determine the impact of RFA on long-term outcomes.

METHOD

This is a retrospective study including patients undergoing LR with or without RFA for CRLM. All variables influencing disease-free survival (DFS) and disease-specific survival (DSS) were examined through a Cox regression analysis before and after propensity-score matching (PSM).

RESULTS

Among the 128 patients included, 71 (55.5%) underwent LR alone and 57 (44.5%) underwent LR+RFA. With univariate analysis, LR+RFA showed a significantly worse DFS than LR alone (p = 0.028), which was not confirmed after PSM (p = 0.064). Thermal ablation did not influence DSS before or after matching (p = 0.282 and p = 0.189). When analyzing the subgroups of patients according to number of RFAs performed, no difference in long-term outcomes was observed (after PSM: p = 0.192 for DFS and p = 0.624 for DSS). Analysis of site of recurrence revealed that neither performing an RFA (p = 0.893) nor the number of lesions ablated (p = 0.093, p = 0.550, and p = 0.087 for 1, 2, and ≥ 2 RFAs) were associated with an increased risk of liver-only relapse.

DISCUSSION

In the setting of a parenchymal sparing strategy, combining RFA with LR is safe in terms of oncological outcomes. Tumor burden, rather than RFA performed, independently influences risk of recurrence and patient survival.

Multiple colorectal liver metastases resection can offer long-term survival: The concept of a chronic neoplastic disease

BACKGROUND

Resection for colorectal liver metastases has evolved significantly and, currently, there are no limits to the number of resected nodules. This study aimed to evaluate the outcomes and prognostic factors after liver resection for patients with ≥4 colorectal liver metastases, emphasizing long-term survival.

METHODS

The study population consisted of 137 patients with ≥4 colorectal liver metastases out of a total of 597 patients with colorectal liver metastases who underwent curative intent liver resection from January 2010 to July 2019 in a single hepatobiliary center.

RESULTS

The probability of overall and disease-free survival at 1, 3, and 5 years was 90.8%, 64.5%, 40.6%, and 37.7%, 19.3%, 18.1%, respectively. In a multivariate analysis for overall survival, the size of the largest metastatic nodule was the only unfavorable factor (P = .001). For disease-free survival, complete pathological response was a favorable factor (P = .04), and the following were negative factors: number of nodules ≥7 (P = .034), radiofrequency ablation during surgery (P = .04), positive primary tumor lymph nodes (P = .034), R1 resection (P = .011), and preoperative carcinoembryonic antigen >20 ng/mL (P = .015). After the first and second years of follow-up, 59 patients (45.3%) and 45 patients (34.6%), respectively, were not receiving chemotherapy. After 5 years of follow-up, 21 (16.1%) multimetastatic patients were chemotherapy-free.

CONCLUSION

A significant number of patients with multiple colorectal liver metastases will present long-term survival and should not be denied surgery. The long-term survival rates, even in the presence of recurrence, characterize a chronic neoplastic disease.

Optimizing the selection of technically unresectable colorectal liver metastases

BACKGROUND

The prediction of conversion surgery in patients with technically unresectable colorectal liver metastases has not been generalized or well-established. We developed a predictive model for conversion surgery and assessed the long-term outcomes of patients with technically unresectable colorectal liver metastases.

METHODS

In this single-center, retrospective study, we analyzed the perioperative parameters and outcomes of 892 consecutive patients (2014-2021). Conversion surgery was indicated when the chemotherapy response allowed the complete resection of colorectal liver metastases with negative margins and adequate remnant liver volume.

RESULTS

Of the 892 patients, 122 had technically unresectable colorectal liver metastases; 61 underwent conversion surgery (conversion surgery group) and 61 did not (nonconversion surgery group). The median overall survival was significantly higher in the conversion surgery group than in the nonconversion surgery group (5.6 vs 1.8 years, P < .001). After univariate and multivariate analyses, the predictive model for conversion surgery was constructed using 4 predictive factors: Rat sarcoma viral oncogene homolog status (mutant, +2 points), tumor number (≥15, +1), hepatic vein contact (≥2 hepatic veins, +1), and the presence of preservable sections (absence of preservable sections, +2). The area under the curve for conversion surgery was 0.889. Patients were graded according to the scores (A [0-2], B [3-4], and C [5-6]), and the conversion rates were 91.5% (A), 32.6% (B), and 10.3% (C) (P < .001). Grade A patients (median survival time, 5.7 years) had significantly better overall survival than grade B and C patients (median survival time, 2.2 and 1.6 years, respectively; P < .001).

CONCLUSION

Patients who underwent conversion surgery for technically unresectable colorectal liver metastases had better prognoses, and our novel predictive model was useful in predicting conversion surgery and prognosis.

Radiofrequency ablation in treatment of hepatic metastases of colorectal cancer

Radiofrequency ablation in treatment of hepatic metastases of colorectal cancer

Clinical strategy of conversion therapy and surgical treatment for liver metastases from colorectal cancer

Colorectal cancer is one of the common malignant tumors of the digestive system in clinical practice. Due to the anatomical characteristics of the colorectum itself, colorectal cancer is prone to liver metastasis. Approximately 15%-25% of colorectal cancer cases are complicated with liver metastasis at diagnosis, 15%-25% are complicated with liver metastasis after radical resection of colorectal cancer, and 80%-90% with liver metastasis cannot undergo radical resection initially. The 5-year survival rate is less than 5%, and liver metastasis is the main cause of death in patients with colorectal cancer. In recent years, with the clinical application of effective chemotherapy and molecular targeted drugs, as well as the rapid development of surgical techniques, an individualized safe, efficient, fast, treatment plan can be formulated according to patients' age, primary colorectal tumor location, degree of differentiation, Ras and B-Raf gene status, tumor size, number and distribution of metastases in the liver. By shrinking the tumor volume in the liver and increasing the residual liver volume, liver metastatic tumors can undergo surgical resection or disease-free status can be achieved in patients with liver metastasis. As a result, patients with colorectal liver metastases can achieve a 5-year survival rate of 30%-57%, which greatly improves the prognosis after operation. According to the postoperative adverse factors, individualized preventive measures are worked out to reduce the impact of adverse factors and improve the prognosis of patients with colorectal liver metastases. In this paper, we systematically discuss the clinical strategy of conversion therapy and surgical treatment for unresectable colorectal cancer liver metastases by reviewing the relevant domestic and foreign literature, so as to provide a theoretical reference for the selection of clinical treatment and program for patients with unresectable colorectal cancer liver metastases.

Current trends in regenerative liver surgery: Novel clinical strategies and experimental approaches

Liver resections are performed to cure patients with hepatobiliary malignancies and metastases to the liver. However, only a small proportion of patients is resectable, largely because only up to 70% of liver tissue is expendable in a resection. If larger resections are performed, there is a risk of post-hepatectomy liver failure. Regenerative liver surgery addresses this limitation by increasing the future liver remnant to an appropriate size before resection. Since the 1980s, this surgery has evolved from portal vein embolization (PVE) to a multiplicity of methods. This review presents an overview of the available methods and their advantages and disadvantages. The first use of PVE was in patients with large hepatocellular carcinomas. The increase in liver volume induced by PVE equals that of portal vein ligation, but both result only in a moderate volume increase. While awaiting sufficient liver growth, 20%–40% of patients fail to achieve resection, mostly due to the progression of disease. The MD Anderson Cancer Centre group improved the PVE methodology by adding segment 4 embolization (“high-quality PVE”) and demonstrated that oncological results were better than non-surgical approaches in this previously unresectable patient population. In 2012, a novel method of liver regeneration was proposed and called Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS). ALPPS accelerated liver regeneration by a factor of 2–3 and increased the resection rate to 95%–100%. However, ALPPS fell short of expectations due to a high mortality rate and a limited utility only in highly selected patients. Accelerated liver regeneration, however, was there to stay. This is evident in the multiplicity of ALPPS modifications like radiofrequency or partial ALPPS. Overall, rapid liver regeneration allowed an expansion of resectability with increased perioperative risk. But, a standardized low-risk approach to rapid hypertrophy has been missing and the techniques used and in use depend on local expertise and preference. Recently, however, simultaneous portal and hepatic vein embolization (PVE/HVE) appears to offer both rapid hypertrophy and no increased clinical risk. While prospective randomized comparisons are underway, PVE/HVE has the potential to become the future gold standard.

Thermal ablation versus hepatic resection for colorectal cancer with synchronous liver metastases: a propensity score matching study

OBJECTIVES

Several studies have compared the efficacy of hepatic resection (HR) and thermal ablation (TA) for unresectable tumors; however, results remain inconsistent. Most cohorts in previous studies were heterogeneous groups of synchronous colorectal liver metastases (CRLM) and extrahepatic metastases. This retrospective study aimed to compare the therapeutic efficacy between TA and HR in synchronous CRLM without extrahepatic metastases.

METHODS

Cases with initially synchronous CRLM without extrahepatic metastases between January 2007 and December 2018 were enrolled. Of the 448 cases, 346 received HR and 102 TA. Propensity score matching with a 1:1 ratio was used to improve the comparability between the HR and TA groups. Technical success, complications, disease-free survival (DFS), and overall survival (OS) were compared before and after matching.

RESULTS

All patients achieved technical success. Major complication rates in the HR and TA groups were, respectively, 36.7% and 8.8% (p < 0.001). Before matching, the 5-year OS and DFS (p = 0.004 and p = 0.020, respectively) were significantly higher in the HR group than in the TA group. After matching, no significant difference in the 5-year OS and DFS was found between the groups (p = 0.770 and p = 0.939, respectively). Local tumor progression rate was significantly higher in the TA group both before (p = 0.027) and after (p = 0.029) matching.

CONCLUSIONS

For patients with CRC with synchronous CRLM, TA and HR provide comparable OS and DFS. TA is preferable if complete ablation is predicted.

KEY POINTS

• Thermal ablation and hepatic resection provide comparable overall survival and disease-free survival. • Thermal ablation is a safe and effective treatment for patients with colorectal cancer with synchronous liver metastases and has a lower major complication rate and higher repeatability than hepatic resection. • Thermal ablation is preferable if complete ablation is predicted.

Radiofrequency ablation in the treatment of hepatocellular carcinoma

OBJECTIVE

The purpose of this article is to discuss the use, comparative efficacy, and research progress of radiofrequency ablation (RFA), alone or in combination with other therapies, for the treatment of hepatocellular carcinoma (HCC).

METHOD

To search and summarize the basic and clinical studies of RFA in recent years.

RESULTS

RFA is one of the radical treatment methods listed in the guidelines for the diagnosis and treatment of HCC. It has the characteristics of being minimally invasive and safe and can obtain good local tumor control, and it can improve the local immune ability, improve the tumor microenvironment and enhance the efficacy of chemotherapy drugs. It is commonly used for HCC treatment before liver transplantation and combined ALPPS and hepatectomy for HCC. In addition, the technology of RFA is constantly developing. The birth of noninvasive, no-touch RFA technology and equipment and the precise RFA concept have improved the therapeutic effect of RFA.

CONCLUSION

RFA has good local tumor control ability, is minimally invasive, is safe and has other beneficial characteristics. It plays an increasingly important role in the comprehensive treatment strategy of HCC. Whether RFA alone or combined with other technologies expands the surgical indications of patients with HCC and provides more benefits for HCC patients needs to be determined.

Parenchymsparende Operationen oder anatomische Resektionen bei Lebermetastasen des kolorektalen Karzinoms?

Darmkrebs ist eine der häufigsten Todesursachen in der westlichen Welt. Die Hälfte der Patienten entwickelt kolorektale Lebermetastasen (CRLM), dabei weisen weniger als 30% der Patienten zum Zeitpunkt der Diagnose eine chirurgisch resektable Metastasierung auf. Im Falle einer Resektabilität bietet die klassische anatomische (Major-)Hepatektomie eine hohe R0-Resektionsrate, allerdings bei gleichzeitig erhöhter Morbidität und Mortalität. In den letzten 2 Jahrzehnten wurden die potenziellen Vorteile der parenchymsparenden Hepatektomie (PSH) in Bezug auf die onkologischen Gesamtergebnisse, das Überleben und die Re-Resektion im Falle eines Rezidivs („Salvageability“) nachgewiesen. Der Beitrag fasst die aktuellen Erkenntnisse zur PSH als chirurgische Therapieoption zusammen und diskutiert den aktuellen „state of the art“ in verschiedenen Szenarien.

Salvage 125I brachytherapy for liver metastases of colorectal cancer in anatomically challenging locations after failure of systemic chemotherapy-A retrospective study

PURPSOE

Colorectal cancer liver metastasis (CCLM) in anatomically challenging locations is difficult to treat. This retrospective study aimed to evaluate the effectiveness and safety of permanent ¹²⁵I seeds implantation (ISI) for treatment of CCLM in anatomically challenging locations after failure of systemic chemotherapy.

METHODS AND MATERIALS

A total of 31 liver metastases (in 25 patients) were treated by ISI under computerized tomography guidance from January 2011 to December 2017. Post-treatment follow-up was for 40 months. Adverse events were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Tumor response was evaluated by the mRECIST criteria. Objective response rate, overall survival rate, and complications were retrospectively analyzed.

RESULTS

All ISI procedures were performed successfully. Most patients only complained of fatigue and mild pain after ISI. Only one patient had liver rupture during the procedure. Serum alanine aminotransferase and aspartate aminotransferase levels at 1 month after ISI were not significantly different from pre-procedure levels (p > 0.05). Computed tomography at 6 months after ISI treatment showed completed response in 11 (11/31, 35.5%) lesions, partial response in 14 (14/31, 45.2%) lesions, stable disease in 4 (4/31, 12.9%) lesions, and disease progression in 2 (2/31, 6.5%) lesions; thus, the objective response rate was 80.6%. Median survival was for 12 months. The 1 and 2 year overall survival rates were 52.0% and 20.0%, respectively.

CONCLUSIONS

¹²⁵I seeds implantation for CCLM in anatomically challenging locations is safe and effective. Survival benefit is limited in the salvage setting where patients have high intrahepatic tumor load after failed systemic chemotherapy.

Improved Outcomes of Thermal Ablation for Colorectal Liver Metastases: A 10-Year Analysis from the Prospective Amsterdam CORE Registry (AmCORE)

Background

To analyze long-term oncological outcomes of open and percutaneous thermal ablation in the treatment of patients with colorectal liver metastases (CRLM).

Methods

This assessment from a prospective, longitudinal tumor registry included 329 patients who underwent 541 procedures for 1350 CRLM from January 2010 to February 2021. Three cohorts were formed: 2010–2013 (129 procedures [53 percutaneous]), 2014–2017 (206 procedures [121 percutaneous]) and 2018–2021 (206 procedures [135 percutaneous]). Local tumor progression-free survival (LTPFS) and overall survival (OS) data were estimated using the Kaplan–Meier method. Potential confounding factors were analyzed with uni- and multivariable Cox regression analyses.

Results

LTPFS improved significantly over time for percutaneous ablations (2-year LTPFS 37.7% vs. 69.0% vs. 86.3%, respectively, P < .0001), while LTPFS for open ablations remained reasonably stable (2-year LTPFS 87.1% [2010–2013], vs. 92.7% [2014–2017] vs. 90.2% [2018–2021], P = .12). In the latter cohort (2018–2021), the open approach was no longer superior regarding LTPFS (P = .125). No differences between the three cohorts were found regarding OS (P = .088), length of hospital stay (open approach, P = .065; percutaneous approach, P = .054), and rate and severity of complications (P = .404). The rate and severity of complications favored the percutaneous approach in all three cohorts (P = .002).

Conclusion

Over the last 10 years efficacy of percutaneous ablations has improved remarkably for the treatment of CRLM. Oncological outcomes seem to have reached results following open ablation. Given its minimal invasive character and shorter length of hospital stay, whenever feasible, percutaneous procedures may be favored over an open approach.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-022-03152-9.

Minimizing the risk of small-for-size syndrome after liver surgery

BACKGROUND

Primary and secondary liver tumors are not always amenable to resection due to location and size. Inadequate future liver remnant (FLR) may prevent patients from having a curative resection or may result in increased postoperative morbidity and mortality from complications related to small-for-size syndrome (SFSS).

DATA SOURCES

This comprehensive review analyzed the principles, mechanism and risk factors associated with SFSS and presented current available options in the evaluation of FLR when planning liver surgery. In addition, it provided a detailed description of specific modalities that can be used before, during or after surgery, in order to optimize the conditions for a safe resection and minimize the risk of SFSS.

RESULTS

Several methods which aim to reduce tumor burden, preserve healthy liver parenchyma, induce hypertrophy of FLR or prevent postoperative complications help minimize the risk of SFSS.

CONCLUSIONS

With those techniques the indications of radical treatment for patients with liver tumors have significantly expanded. The successful outcome depends on appropriate patient selection, the individualization and modification of interventions and the right timing of surgery.

A visualization method for a wide range of rising temperature induced by high-intensity focused ultrasound using a tissue-mimicking phantom

PURPOSE

High-intensity focused ultrasound (HIFU) treatment requires prior evaluation of the HIFU transducer output. A method using micro-capsulated thermochromic liquid crystal (MTLC) to evaluate the temperature distribution in the media during HIFU exposure has been previously developed. However, the color-coded temperature range of commercial MTLC is approximately 10 °C, which is insufficient for temperature measurement for HIFU exposure. We created two layers of tissue-mimicking phantoms with different color-coded temperature ranges, and a new visualization method was developed by utilizing the axisymmetric pressure distribution of a HIFU focus.

METHODS

A two-layer phantom with two sensitivity ranges was created. The HIFU transducer was set to align the focal point to the boundary between the two layers. Images of the upper and lower layers were flipped along the boundary between the two layers such that they overlapped with each other, assuming the pressure distribution of HIFU to be axisymmetric.

RESULTS

The experimental and simulation results were compared to evaluate the accuracy of the phantom temperature measurement. The experimental time profile of the temperature and spatial distribution around the HIFU focus matched well with that of the simulation. However, there is room for improvement in the accuracy in the axial direction of HIFU focus.

CONCLUSION

Users can apply our proposed method in clinical practice to promptly assess the output of the HIFU transducer before treatment.

[Multimodal, interdisciplinary therapeutic concepts for liver metastasized colorectal cancer]

About half of all patients with colorectal carcinoma (CRC) develop metastases mainly in the liver during the course of their disease. Metastatic disease is associated with a low 5-year overall survival rate of only 5-7 %, particularly when there is no possibility of local treatment. However, if there is an opportunity to resect the metastases, especially isolated liver metastases, the chance of long-term survival is approximately 15-27 % after both primary resection or secondary resection after neoadjuvant pretreatment. Overall, long-term survival of patients with metastatic CRC has improved significantly in recent years due to a combination of modern systemic therapies, advanced liver surgery and local ablative procedures.Of note, for the vast majority of patients, metastatic resection does not mean cure, but a significant prolongation of overall survival with a good quality of life. Chemotherapy-free intervals after metastasis resection maintain quality of life and can help to reduce toxicity.In this review, we would like to present the "toolbox" for the multidisciplinary treatment of metastatic CRC and give recommendations how the individual modalities should be optimally used, considering tumor-specific characteristics and patient preferences.

Comparison of intrahepatic progression patterns of hepatocellular carcinoma and colorectal liver metastases following CT-guided high dose-rate brachytherapy

Introduction:

Given the metachronous and multifocal occurrence of hepatocellular carcinoma (HCC) and colorectal cancer metastases in the liver (CRLM), this study aimed to compare intrahepatic progression patterns after computed tomography (CT)-guided high dose-rate brachytherapy.

Patients and methods:

This retrospective analysis included 164 patients (114 HCC, 50 CRLM) treated with brachytherapy between January 2016 and January 2018. Patients received multiparametric magnetic resonance imaging (MRI) before, and about 8 weeks after brachytherapy, then every 3 months for the first, and every 6 months for the following years, until progression or death. MRI scans were assessed for local or distant intrahepatic tumor progression according to RECIST 1.1 and electronic medical records were reviewed prior to therapy. The primary endpoint was progression-free survival (PFS). Specifically, local and distant intra-hepatic PFS were assessed to determine differences between the intrahepatic progression patterns of HCC and CRLM. Secondary endpoints included the identification of predictors of PFS, time to progression (TTP), and overall survival (OS). Statistics included Kaplan–Meier analysis and univariate and multivariate Cox regression modeling.

Results:

PFS was longer in HCC [11.30 (1.33–35.37) months] than in CRLM patients [8.03 (0.73–19.80) months, p = 0.048], respectively. Specifically, local recurrence occurred later in HCC [PFS: 36.83 (1.33–40.27) months] than CRLM patients [PFS: 12.43 (0.73–21.90) months, p = 0.001]. In contrast, distant intrahepatic progression occurred earlier in HCC [PFS: 13.50 (1.33–27.80) months] than in CRLM patients [PFS: 19.80 (1.43–19.80) months, p = 0.456] but without statistical significance. Multivariate Cox regression confirmed tumor type and patient age as independent predictors for PFS.

Conclusion:

Brachytherapy proved to achieve better local tumor control and overall PFS in patients with unresectable HCC as compared to those with CRLM. However, distant progression preceded local recurrence in HCC. As a result, these findings may help design disease-specific surveillance strategies and personalized treatment planning that highlights the strengths of brachytherapy. They may also help elucidate the potential benefits of combinations with other loco-regional or systemic therapies.

Borderline resectable for colorectal liver metastases: Present status and future perspective

Surgical resection for colorectal liver metastases (CRLM) may offer the best opportunity to improve prognosis. However, only about 20% of CRLM cases are indicated for resection at the time of diagnosis (initially resectable), and the remaining cases are treated as unresectable (initially unresectable). Thanks to recent remarkable developments in chemotherapy, interventional radiology, and surgical techniques, the resectability of CRLM is expanding. However, some metastases are technically resectable but oncologically questionable for upfront surgery. In pancreatic cancer, such cases are categorized as “borderline resectable”, and their definition and treatment strategies are explicit. However, in CRLM, although various poor prognosis factors have been identified in previous reports, no clear definition or treatment strategy for borderline resectable has yet been established. Since the efficacy of hepatectomy for CRLM was reported in the 1970s, multidisciplinary treatment for unresectable cases has improved resectability and prognosis, and clarifying the definition and treatment strategy of borderline resectable CRLM should yield further improvement in prognosis. This review outlines the present status and the future perspective for borderline resectable CRLM, based on previous studies.

Image-Guided Ablation for Colorectal Liver Metastasis: Principles, Current Evidence, and the Path Forward

Image-guided ablation can provide effective local tumor control in selected patients with CLM. A randomized controlled trial suggested that radiofrequency ablation combined with systemic chemotherapy resulted in a survival benefit for patients with unresectable CLM, compared to systemic chemotherapy alone. For small tumors, ablation with adequate margins can be considered as an alternative to resection. The improvement of ablation technologies can allow the treatment of tumors close to major vascular structures or bile ducts, on which the applicability of thermal ablation modalities is challenging. Several factors affect the outcomes of ablation, including but not limited to tumor size, number, location, minimal ablation margin, RAS mutation status, prior hepatectomy, and extrahepatic disease. Further understanding of the impact of tumor biology and advanced imaging guidance on overall patient outcomes might help to tailor its application, and improve outcomes of image-guided ablation.

HIFU for the treatment of gastric cancer with liver metastases with unsuitable indications for hepatectomy and radiofrequency ablation: a prospective and propensity score-matched study

Background

The purpose of this study was to explore the efficacy and safety of high intensity focused ultrasound (HIFU) in gastric cancer with liver metastasis (GCLM) patients who were contraindicated for either hepatectomy or radiofrequency ablation (RFA).

Methods

This is a prospective, observational study on GCLM patients with 1–3 liver metastases. The primary gastric lesions were thoroughly resected and any case that exhibited extra-hepatic metastasis was excluded. A 1:2:2 propensity score-matching analysis was performed using a logistic regression model on the HIFU group, best supportive care (BSC) group, and palliative chemotherapy (PC) group. The primary endpoints include progression-free survival (PFS) and overall survival (OS).

Results

Forty patients were finally included, there were 8 cases in HIFU group, 16 cases in BSC group, and 16 cases in PC group. The median follow-up time for the entire cohort was 10 months. The median PFS was 16.5 months in HIFU group, 2 months in BSC group, and 5 months in PC group. The median OS was 27.5 months in the HIFU group, 7 months in the BSC group, and 11.5 months in the PC group. Additionally, no grade 3 or higher adverse events occurred in the HIFU group.

Conclusion

The results of this study showed that HIFU treatment could improve the long-term prognosis of GCLM patients without a significant increase in the occurrence of adverse events. Compared with PC and BSC, HIFU is the preferred treatment option when GCLM patients without extra-hepatic metastasis are unable to undergo either surgery or RFA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01307-y.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Two-Stage Hepatectomy for Bilateral Colorectal Liver Metastases: A Multi-institutional Analysis

BACKGROUND

Two-stage hepatectomy (TSH) is an important tool in the management of bilateral colorectal liver metastases (CRLM). This study sought to examine the presentation, management, and outcomes of patients completing TSH in major hepatobiliary centers in the United States (US).

METHODS

A retrospective review from five liver centers in the US identified patients who completed a TSH procedure for bilateral CRLM.

RESULTS

From December 2000 to March 2016, a total of 196 patients were identified. The majority of procedures were performed using an open technique (n = 194, 99.5%). The median number of tumors was 7 (range 2-33). One-hundred and twenty-eight (65.3%) patients underwent portal vein embolization. More patients received chemotherapy prior to the first stage than chemotherapy administration preceding the second stage (92% vs. 60%, p = 0.308). Median overall survival (OS) was 50 months, with a median follow-up of 28 months (range 2-143). Hepatic artery infusion chemotherapy was administered to 64 (32.7%) patients with similar OS as those managed without an infusion pump (p = 0.848). Postoperative morbidity following the second-stage resection was 47.4%. Chemotherapy prior to the second stage did not demonstrate an increased complication rate (p = 0.202). Readmission following the second stage was 10.3% and was associated with a decrease in disease-free survival (p = 0.003). OS was significantly decreased by positive resection margins and increased estimated blood loss (EBL; p = 0.036 and p = 0.05, respectively).

CONCLUSION

This is the largest TSH series in the US and demonstrates evidence of safety and feasibility in the management of bilateral CRLM. Outcomes are influenced by margin status and operative EBL.

Clinical practice guidelines for the management of liver metastases from extrahepatic primary cancers 2021

BACKGROUND

Hepatectomy is standard treatment for colorectal liver metastases; however, it is unclear whether liver metastases from other primary cancers should be resected or not. The Japanese Society of Hepato-Biliary-Pancreatic Surgery therefore created clinical practice guidelines for the management of metastatic liver tumors.

METHODS

Eight primary diseases were selected based on the number of hepatectomies performed for each malignancy per year. Clinical questions were structured in the population, intervention, comparison, and outcomes (PICO) format. Systematic reviews were performed, and the strength of recommendations and the level of quality of evidence for each clinical question were discussed and determined. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The eight primary sites were grouped into five categories based on suggested indications for hepatectomy and consensus of the guidelines committee. Fourteen clinical questions were devised, covering five topics: (1) diagnosis, (2) operative treatment, (3) ablation therapy, (4) the eight primary diseases, and (5) systemic therapies. The grade of recommendation was strong for one clinical question and weak for the other 13 clinical questions. The quality of the evidence was moderate for two questions, low for 10, and very low for two. A flowchart was made to summarize the outcomes of the guidelines for the indications of hepatectomy and systemic therapy.

CONCLUSIONS

These guidelines were developed to provide useful information based on evidence in the published literature for the clinical management of liver metastases, and they could be helpful for conducting future clinical trials to provide higher-quality evidence.

Outcomes following potentially curative therapies for older patients with metastatic colorectal cancer

Older age represents a major risk factor for developing colorectal cancer and the disease disproportionately affects patients older than 60 years of age. However, knowledge regarding the optimal management of older patients with metastatic colorectal cancer (mCRC) remains limited. The challenge of treating older patients arises in tailoring treatments to a heterogeneous cohort whilst adjusting for individuals with a wide variation of physiological reserve, a reduced tolerance to treatment side-effects and morbidity, and often different priorities as compared with younger patients. Data from the published literature supports the premise that older age alone is not an acceptable determinant of treatment options. In particular, patients aged 65-70 years with mCRC ought to be considered similarly to younger patients and patients aged 70-74 also stand to benefit from both hepatic resection and systemic therapy notwithstanding the higher rates of morbidity and mortality. Patients aged 75-79, and with sufficient physiological reserve ought to be considered for curative treatment options which are proportional to the extent of metastatic disease. Meanwhile, in patients aged ≥80 years, life-extending or life-enhancing benefit ought to be demonstrable prior to embarking upon major surgery as a curative treatment option. Older patients who meet the physiological eligibility criteria to enter clinical trials of systemic chemotherapy appear to gain similar benefit as younger patients and should not be excluded on the basis of age alone. Clinical trials that are specifically designed for older patients are feasible and could yield valuable information to guide clinical practice.

Limitations in resectability of colorectal liver metastases 2020 - A systematic approach for clinicians and patients

Colorectal liver metastases (CRLM) affect over 50 % of all patients with colorectal cancer, which is the second leading cause of cancer in the western world. Resection of CRLM may provide cure and improves survival over chemotherapy alone. However, resectability of CLRM has to be decided in multidisciplinary tumor boards and is based on oncological factors, technical factors and patient factors. The advances of chemotherapy lead to the abolition of contraindications to resection in favor of technical resectability, but somatic mutations and molecular subtyping may improve selection of patients for resection in the future. Technical factors center around anatomy of the lesions, volume of the remnant liver and quality of the liver parenchymal. Multiple strategies have been developed to overcome volume limitations and they are reviewed here. The least investigated topic is how to select the right patients among an elderly and frail patient population for the large variety of technical options specifically for bi-lobar CRLM to keep 90-day mortality as low as possible. The review is an overview over the current state-of-the art and a systematic guide to the topic of resectability of CRLM for both clinicians and patients.

The actual management of colorectal liver metastases

Colorectal cancer is one of the most frequent cancers in the world and between 50% and 60% of patients will develop colorectal liver metastases (CRLM) during the disease. There have been great improvements in the management of CRLM during the last decades. The combination of modern chemotherapeutic and biological systemic treatments with aggressive surgical resection strategies is currently the base for the treatment of patients considered unresectable until few years ago. Furthermore, several new treatments for the local control of CRLM have been developed and are now part of the arsenal of multidisciplinary teams for the treatment of these complex patients. The aim of this review was to summarize and update the management of CRLM, its controversies and relevant evidence.

What's New in Percutaneous Ablative Strategies for Hepatocellular Carcinoma and Colorectal Hepatic Metastases? 2020 Update

PURPOSE OF REVIEW

Ablation techniques are now well-established treatment options available for the management of primary and secondary hepatic malignancies. Currently available ablative techniques include radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, and irreversible electroporation (IRE). Along with advances in navigational devices and targeting technologies, ablation combined with other therapies may be the next therapeutic option in thermal ablation. The purpose of this review is to evaluate the current status of ablative technologies in interventional and medical oncology for management of liver malignancies.

RECENT FINDINGS

With the use of combination techniques (i.e., ablation and transarterial embolization procedures), thermal ablation is now moving toward treating tumors larger than 3 cm in size or tumors with macrovascular invasion. Ongoing trials are examining the optimum timing of combination therapies. Thermal ablation combined with hepatic resection may increase the number of patients with metastatic colorectal carcinoma to the liver who qualify for curative surgery. Combination therapies of thermal ablation and transarterial embolization allow for promising treatment responses for larger HCC. Surgery combined with thermal ablation can potentially increase the number of patients with metastatic colon cancer to the liver who qualify for curative surgery.

Predicting liver metastases growth patterns: Current status and future possibilities

Colorectal cancer is highly incident worldwide and presents a health burden with elevated mortality rate despite prevention, detection, and treatment, mainly due to metastatic liver disease. Histological growth patterns of colorectal cancer liver metastases have emerged as a reproducible prognostic factor, with biological implications and therapeutic windows. Nonetheless, the histological growth patterns of colorectal cancer liver metastases are only known after pathological examination of a liver resection specimen, thus limiting the possibilities of pre-surgical decision. Predicting the histological growth pattern of colorectal cancer liver metastases would provide valuable information for patient-tailored medicine. In this article, we perform a review of the histological growth patterns and their implications, with a focus on the possibilities for their prediction.

MRI-guided percutaneous thermoablation in combination with hepatic resection as parenchyma-sparing approach in patients with primary and secondary hepatic malignancies: single center long-term experience

BACKGROUND

Combination therapy using hepatic resection (HR) and intra-operative thermal ablation is a treatment approach for patients with technically unresectable liver malignancies. The aim of this study was to investigate safety, survival and local recurrence rates for patients with technically unresectable liver tumors undergoing HR and separate percutaneous MR-guided thermoablation procedure as an alternative approach.

METHODS

Data from all patients with primary or secondary hepatic malignancies treated at a single institution between 2004 and 2018 with combined HR and MR-guided percutaneous thermoablation was collected and retrospectively analyzed. Complications, procedure related information and patient characteristics were collected from institutional records. Overall survival and disease-free survival were estimated using the Kaplan-Meier method.

RESULTS

A total of 31 patients (age: 62.8 ± 9.1 years; 10 female) with hepatocellular carcinoma (HCC; n = 7) or hepatic metastases (n = 24) were treated for 98 hepatic tumors. Fifty-six tumors (mean diameter 28.7 ± 23.0 mm) were resected. Forty-two tumors (15.1 ± 7.6 mm) were treated with MR-guided percutaneous ablation with a technical success rate of 100%. Local recurrence at the ablation site occurred in 7 cases (22.6%); none of these was an isolated local recurrence. Six of 17 patients (35.3%) treated for colorectal liver metastases developed local recurrence. Five patients developed recurrence at the resection site (16.1%). Non-local hepatic recurrence was observed in 18 cases (58.1%) and extrahepatic recurrence in 11 cases (35.5%) during follow-up (43.1 ± 26.4 months). Ten patients (32.3%) developed complications after HR requiring pharmacological or interventional treatment. No complication requiring therapy was observed after ablation. Median survival time was 44.0 ± 7.5 months with 1-,3-, 5-year overall survival rates of 93.5, 68.7 and 31.9%, respectively. The 1-, 3- and 5-year disease-free survival rates were 38.7, 19.4 and 9.7%, respectively.

CONCLUSION

The combination of HR and MR-guided thermoablation is a safe and effective approach in the treatment of technically unresectable hepatic tumors and can achieve long-term survival.

HIFU for the treatment of difficult colorectal liver metastases with unsuitable indications for resection and radiofrequency ablation: a phase I clinical trial

BACKGROUND

The goal of this study is to evaluate the safety and efficacy of high intensity focused ultrasound (HIFU) for patients with colorectal liver metastases (CRLM) but were contraindicated for resection and radiofrequency ablation.

METHODS

Patients between 20 and 80 years of age with 1-3 liver metastases from colorectal cancer were selected. Included patients have had their primary lesions removed with no evidence of extrahepatic metastasis prior to the study. Ultrasound-guided HIFU was employed and target regions' ablation was achieved with repeated sonications from the deep to shallow regions of the tumors section by section.

RESULTS

Thirteen patients were enrolled. The most common adverse events (AEs) were pain (n = 8), followed by fatigue (n = 7), increased aspartate aminotransferase (AST) (n = 7), increased alanine aminotransferase (ALT) (n = 5), and skin edema (n = 4). No grade ≥ 3 AEs occurred and while most patients (76.9%) achieved a complete response, three patients achieved a partial response. The objective response rate was 100% after the first HIFU treatment. Nine patients relapsed but the tumors were mostly isolated to the liver (8/9). The median follow-up period was 25 months. The 2-year progression-free survival (PFS) was 16.7%, and the median PFS was 9 months. Notably, the 2-year overall survival (OS) was 77.8%, and the median OS was 25 months.

CONCLUSION

This study indicates that the HIFU treatment is safe, is able to achieve a good tumor response rate and long-term prognosis even when the foci were in high-risk locations, and should be considered for patients who were considered unsuitable for other local treatments.

Clinical outcomes of patients with duodenal adenocarcinoma and intestinal-type papilla of Vater adenocarcinoma

BACKGROUND

Duodenal adenocarcinoma (DA) and intestinal-type papilla of Vater adenocarcinoma (it-PVA) are rare malignancies of the gastrointestinal tract. Current therapeutic options are translated nowadays from treatment strategies for patients with colorectal cancer due to histopathological similarities.

AIM

To retrospectively investigate the clinical outcome of patients with DA and it-PVA.

METHODS

All patients with DA and it-PVA diagnosed between 2000 and 2017 were included at two academic centers in the Netherlands. All patients with histopathologically-confirmed DA or it-PVA were eligible for inclusion. Clinical outcome was compared between DA and it-PVA per disease stage. In the subgroup of stage IV disease, survival after local treatment of oligometastases was compared with systemic therapy or supportive care.

RESULTS

In total, 155 patients with DA and it-PVA were included. Patients with it-PVA more often presented with stage I disease, while DA was more often diagnosed at stage IV (P < 0.001). Of all patients, 79% were treated with curative intent. The median survival was 39 mo, and no difference in survival was found for patients with DA and it-PVA after stratification for disease stage. Seven (23%) of 31 patients with synchronous stage IV disease underwent resection of the primary tumor, combined with local treatment of oligometastases. Local treatment of metastases was associated with an overall survival of 37 mo, compared to 14 and 6 mo for systemic therapy and supportive care, respectively.

CONCLUSION

Survival of patients with DA and it-PVA is comparable per disease stage. These results suggest a potential benefit for local treatment strategies in selected patients with oligometastases, although additional prospective studies are needed.

Laparoscopic Versus Open Thermal Ablation of Colorectal Liver Metastases: A Propensity Score-Based Analysis of Local Control of the Ablated Tumors

BACKGROUND

Laparoscopic ablation (LA) of colorectal liver metastases (CRLMs) is frequently performed in combination with laparoscopic liver resection or as a stand-alone procedure. However, LA is technically demanding and whether the results are comparable with those of open ablation (OA) has not been determined to date. This study compared the effectiveness of LA and OA in achieving local tumor control of CRLMs.

METHODS

Patients undergoing LA or OA of CRLMs at Ghent University Hospital between June 2007 and February 2018 were identified from a prospective database. Lesions treated by LA and OA were matched 1:1 using a propensity score based on lesions (liver segment, size, deepness, proximity to a vessel), patients, and procedural characteristics. Ablation sites were followed up with computed-tomography or magnetic resonance imaging to assess the completeness of the ablation and ablation-site recurrence (ASR). Analysis of ASR was performed with the Kaplan-Meier method and Cox regression.

RESULTS

In this study, 163 patients underwent the surgical ablation (78 LA, 85 OA) of 333 CRLMs (143 LA, 190 OA). After matching, 220 lesions (110 LA, 110 OA) were analyzed. Ablation was complete in 93.7% (LA) and 97.3% (OA) of the sites (p = 0.195). No difference in ASR was observed (p = 0.351), with a cumulative risk of ASR at 12 months of 9.1% (LA) and 8.2% (OA). After multivariable analysis, ASR was confirmed to be independent of the surgical approach.

CONCLUSION

The findings showed that LA and OA achieve a comparable local control of CRLMs. This result further supports the adoption of a laparoscopic approach for the treatment of CRLMs.

Radiofrequency ablation with four electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling. Influence of electric and activation mode on coagulation size and geometry

PURPOSE

Radiofrequency ablation (RFA) is increasingly being used to treat unresectable liver tumors. Complete ablation of the tumor and a safety margin is necessary to prevent local recurrence. With current electrodes, size and shape of the ablation zone are highly variable leading to unsatisfactory local recurrence rates, especially for tumors >3 cm. In order to improve predictability, we recently developed a system with four simple electrodes with complete ablation in between the electrodes. This rather small but reliable ablation zone is considered as a building block for matrix radiofrequency ablation (MRFA). In the current study we explored the influence of the electric mode (monopolar or bipolar) and the activation mode (consecutive, simultaneous or switching) on the size and geometry of the ablation zone.

MATERIALS AND METHODS

The four electrode system was applied in ex vivo bovine liver. The electric and the activation mode were changed one by one, using constant power of 50 W in all experiments. Size and geometry of the ablation zone were measured. Finite element method (FEM) modelling of the experiment was performed.

RESULTS

In ex vivo liver, a complete and predictable coagulation zone of a 3 × 2 × 2 cm block was obtained most efficiently in the bipolar simultaneous mode due to the combination of the higher heating efficacy of the bipolar mode and the lower impedance by the simultaneous activation of four electrodes, as supported by the FEM simulation.

CONCLUSIONS

In ex vivo liver, the four electrode system used in a bipolar simultaneous mode offers the best perspectives as building block for MRFA. These results should be confirmed by in vivo experiments.

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.

Hepatic metastasis from colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in the world. About two third of patients with CRC will develop distant recurrence at some point in time. Liver is the most common site where distant metastasis takes place. While the overall survival (OS) of patients with metastatic CRC was poor about 3 decades ago, there has been tremendous improvement in this area in the recent years. With the advent of effective systemic chemotherapy and biologic agents and better understanding of the biological behaviour of the tumour, aggressive treatment strategies such as metastatectomy of the liver metastases (or lung metastases) are now acceptable. More importantly, it has transformed the way how stage IV CRCs are being managed. From predominantly palliative as the primary aim, a comprehensive multidisciplinary approach is now the mainstay of treatment with very successful outcomes. Combination of systemic therapies with liver resection has been shown to be effective in providing promising survival benefits. In addition, other adjunctive modalities in targeting the liver metastases such as ablation, combining resection and ablation, transarterial chemoembolization, stereotactic body radiotherapy (SBRT), hepatic artery perfusion, etc. have also been demonstrated variable outcome in treating colorectal liver metastasis (CRLM). Very recently, transplant oncologists have also explored using liver transplantation as a treatment modality for unresectable CRLM, which has demonstrated very good long-term survival in well selected cases. The new paradigm in the treatment of metastatic CRC has dawned.

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.

Fibrinogen-Albumin Ratio Index (FARI): A More Promising Inflammation-Based Prognostic Marker for Patients Undergoing Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Systemic inflammation response is involved in the development and progression of cancers. This study aimed to evaluate the prognostic value of a preoperative Fibrinogen-Albumin Ratio Index (FARI) in patients undergoing hepatectomy for colorectal liver metastases (CRLM) and compare it with established systemic inflammation markers, including the neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammation index.

METHODS

Patients who underwent hepatectomy for CRLM between November 2002 and December 2016 were considered for inclusion. Time-dependent receiver operating characteristic (ROC) curve analysis was conducted to evaluate the ability of markers in predicting survival. Multivariable Cox regression analysis was used to identify independent predictors for overall survival (OS) or disease-free survival (DFS).

RESULTS

A total of 452 consecutive patients were enrolled. The areas under the ROC curve of the FARI in predicting OS and DFS were superior to other inflammatory markers and carcinoembryonic antigen (CEA). The optimal cut-off value of the FARI was 7.6%. Patients with a high FARI (> 7.6%) showed significantly decreased OS and DFS (all p < 0.001). In multivariable analysis, the FARI was the only inflammatory marker that independently predicted OS and DFS. Additionally, regardless of patients having a high or low CEA, the FARI further stratified these patients into subgroups with significantly distinct OS and DFS (all p < 0.05). The FARI also showed good clinical utility in patients with different clinical characteristics.

CONCLUSIONS

A preoperative FARI is an independent predictor of OS and DFS for patients undergoing hepatectomy for CRLM, superior to the established systemic inflammation markers and CEA.

The impact of resection margin on overall survival for patients with colon cancer liver metastasis varied according to the primary cancer location

INTRODUCTION

Investigation into right and left-sided primary colon liver metastasis (CLM) has revealed differences in the tumor biology and prognosis. This indicates that preoperative and operative factors may affect outcomes of right-sided primary CLM differently than left. This retrospective analysis investigated the effects of resection margin stratified by left and right-sided primary CLM on overall survival (OS) for patients undergoing hepatectomy.

METHODS

A total of 732 patients undergoing hepatic resection for CLM at the Cleveland Clinic and Johns Hopkins were identified between 2002 and 2016. Clinically significant variables were analyzed using Cox proportional hazard regression. The cohort was then divided into patients with right and left-sided CLM and analyzed separately using Kaplan Meier analysis and Cox proportional hazard regression.

RESULTS

Cox proportional hazard regression showed that left-sided CLM with an R0 margin was a statistically significant predictor of OS even after controlling for other important factors (HR = 0.629, P = 0.024) but right-sided CLM with R0 margin was not (HR = 0.788, P = 0.245). Kaplan-Meier analysis demonstrated that patients with a left-sided CLM and R0 margin had the best prognosis (P = 0.037).

CONCLUSION

Surgical margin is an important prognostic factor for left-sided primary CLM but tumor biology may override surgical technique for right-sided CLM.