Radiofrequency Ablation to Improve Survival After Conversion Chemotherapy for Colorectal 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.

Neoadjuvant Chemotherapy Followed by Radiofrequency Ablation May Be a New Treatment Modality for Colorectal Liver Metastasis: A Propensity Score Matching Comparative Study

Background: Most colorectal liver metastases (CRLM) are not candidates for liver resection. Radiofrequency ablation (RFA) plays a key role in selected CRLM patients. Neoadjuvant chemotherapy (NAC) followed by liver resection has been widely used for resectable CRLM. Whether NAC followed by radiofrequency ablation (RFA) can achieve a similar prognosis to NAC followed by hepatectomy remains is unclear. The present study aimed to provide a new treatment modality for CRLM patients. Methods: This comparative retrospective research selected CRLM patients from 2009 to 2022. They were divided into NAC + RFA group and NAC + hepatectomy group. The propensity score matching (PSM) was used to reduce bias. We used multivariate cox proportional hazards regression analysis to explore independent factors affecting prognosis. The primary study endpoint was the difference in the progression-free survival (PFS) between the two groups. Results: A total of 190 locally curable CRLM patients were in line with the inclusion criteria. A slight bias was detected in the comparison of basic clinical characteristics between the two groups. RFA showed a significant advantage in the length of hospital stay (median; 2 days vs. 7 days; p < 0.001). The 1- and 3-year PFS in the liver resection and the RFA groups was 57.4% vs. 86.9% (p < 0.001) and 38.8% vs. 55.3% (p = 0.035), respectively. The 1-year and 3-year OS in the liver resection and RFA groups was 100% vs. 96.7% (p = 0.191) and 73.8% vs. 73.6% (p = 0.660), respectively. Conclusions: NAC followed by RFA has rapid postoperative recovery, fewer complications, and better prognosis.

Neoadjuvant Chemotherapy Followed by Radiofrequency Ablation Prolongs Survival for Ablatable Colorectal Liver Metastasis: A Propensity Score Matching Comparative Study

Background

Typically, colorectal liver metastasis (CRLM) is not a candidate for hepatectomy. Radiofrequency ablation (RFA) plays a critical role in unresectable CRLM patients. Nevertheless, high local tumor progression (LTP) and distant metastasis limit the development and further adoption and use of RFA. Neoadjuvant chemotherapy (NAC) has been widely used in resectable CRLM and is recommended by the guidelines. There are no studies on whether NAC can improve the prognosis in ablatable CRLM patients. The present study aimed to determine the feasibility and effectiveness of RFA plus NAC.

Methods

This retrospective cohort included CRLM patients from Zhejiang Cancer Hospital records, who received RFA from January 2009 to June 2020 and were divided into two groups according to the presence or absence of NAC. The Kaplan–Meier method was used to evaluate the 3-year local tumor progression-free survival (LTPFS), progression-free survival (PFS), and overall survival (OS) of the two groups. The propensity score matching was used to reduce bias when assessing survival. Multivariate Cox proportional hazards regression analysis was used to study the independent factors affecting LTPFS, PFS, and OS.

Results

A total of 149 CRLM patients (88 in the RFA alone group and 61 in the plus NAC group) fulfilled the inclusion criteria. Post-RFA complications were 3.4% in the RFA alone group and 16.4% in the plus NAC group. The 3-year LTPFS, PFS, and OS of the RFA only group were 60.9%, 17.7%, and 46.2%, respectively. The 3-year LTPF, PFS, and OS of the plus NAC group were 84.9%, 46.0%, and 73.6%, respectively. In the 29 pairs of propensity score matching cohorts, the 3-year LTPFS, PFS, and OS in the plus NAC group were longer than those in the RFA group (P < 0.05). NAC was an independent protective factor for LTPFS, PFS, and OS (P < 0.05).

Conclusions

For ablatable CRLM patients, RFA plus NAC obtained a better prognosis than RFA alone. Based on the current results, the application of NAC before RFA may become the standard treatment.

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.

Ultrasound-guided secondary radiofrequency ablation combined with chemotherapy in gastric cancer with recurrent liver metastasis

Background

The incidence and mortality of gastric cancer are in the second and third place of malignant tumor in China, respectively. Liver metastasis is an important cause of death of these patients. This study is to explore whether the secondary radiofrequency ablation (RFA) treatment can prolong the survival period and improve the life quality of patients with gastric cancer and recurrent liver metastases.

Methods

A total of 87 patients with gastric cancer and recurrent liver metastases were retrospective analyzed, 46 cases were assigned into study group and 41 cases in control group. The efficacy of the two groups was observed, and the prognostic factors were analyzed.

Results

The median survival time in the study group was significantly longer than that in the control group (P<0.05). The survival rate of the study group was significantly higher than that of the control group (both P<0.05). The life quality scores of the study group were significantly higher than the control group (both P<0.05).

Conclusions

Ultrasound-mediated secondary RFA combined with chemotherapy is superior to chemotherapy alone in the treatment of gastric cancer with recurrent liver metastases.

Non-response to preoperative chemotherapy is a contraindication to hepatectomy plus radiofrequency ablation in patients with colorectal liver metastases

The long-term outcome of 228 patients with colorectal liver metastases (CRLM) who underwent preoperative chemotherapy followed by hepatectomy ± RFA were retrospectively analyzed. Stratified by chemotherapy response, patients were divided into responding (n=129) and non-responding groups (n=99). Patients who underwent hepatectomy-RFA had a greater number of metastases (median of 4 vs. 2, p=0.000), a higher incidence of bilobar involvement (66.7% vs. 49.1%, p=0.014) and longer chemotherapy cycles (median of 6 vs. 4, p=0.000). In the responding group, the median overall survival (OS) and recurrence free survival (RFS) of hepatectomy-RFA and the hepatectomy alone subgroups were comparable (38.6 months vs. 43.2 months, p=0.824; 8.2 months vs. 11.4 months, p=0.623). In the non-responding group, the median OS and RFS of patients treated with hepatectomy-RFA were significantly shorter (18.5 months vs. 34.2 months, p=0.000; 5.1 months vs. 5.9 months, p=0.002). RFA was identified as the unfavorable independent factor for both OS (HR=3.60, 95%CI=1.81-7.16, p=0.039) and RFS (HR=1.70, 95%CI=1.00-2.86, p=0.048) in non-responsive patients. Local recurrence rate after hepatectomy-RFA was higher in the non-responding group (48.1% vs. 23.6%, p=0.018). Non-response to preoperative chemotherapy may be a contraindication to hepatectomy-RFA in patients with CRLM.

Microwave ablation of liver malignancies: comparison of effects and early outcomes of percutaneous and intraoperative approaches with different liver conditions : New advances in interventional oncology: state of the art

Liver thermal ablation is an alternative treatment for hepatocellular carcinoma (HCC) and secondary liver malignancies. Microwave ablation (MWA) produces large ablation zones (AZ) in short time; however, AZ prediction is based on preclinical ex vivo models, rising concerns about reproducibility and safety in humans. We aimed to investigate the effects produced by a new-generation MWA system on human liver in vivo with different approaches (percutaneous or intraoperative) and liver conditions (cirrhosis or previous chemotherapy treatment), in comparison with manufacturer-provided predictions based on ex vivo animal models. Complete tumor ablation (CA) and early clinical outcomes were also assessed. From October 2014, 60 consecutive patients (cirrhotic = 31; non-cirrhotic = 10; chemotherapy-treated = 19) with 81 liver nodules (HCC = 31; mets = 50) underwent MWA procedures (percutaneous = 30; laparotomic = 18; laparoscopic = 12), with a 2450 MHz/100 W generator with Thermosphere™ Technology (Emprint™, Medtronic). A contrast-enhanced CT or MR was performed after one month to assess CA and measure AZ. A linear correlation between AZ volumes and ablation times was observed in vivo, without differences from manufacturer-provided ex vivo predictions in all operative approaches and liver conditions. Other independent variables (sex, age, nodule location) showed no relationship when added to the model. Median (IQR) longitudinal and transverse roundness-indexes of the AZs were, respectively, 0.77(0.13) and 0.93(0.11). CA at 1 month was 93% for percutaneous and 100% for intraoperative procedures (p = 0.175). Thirty-day morbidity and mortality were 3% and 0%. MWA with Thermosphere™ Technology produces predictable AZs on human liver in vivo, according to manufacturer-provided ex vivo predictions. In our experience, this new-generation MWA system is effective and safe to treat liver malignancies in different operative and clinical settings.

Comparison of overall survival in patients with unresectable hepatic metastases with or without transarterial chemoembolization: A Propensity Score Matching Study

Transarterial chemoembolization (TACE) has mostly been used in hypervascular tumours such as hepatocellular carcinoma, and may be an effective palliative treatment in patients with metastatic liver cancer. Our goal is to determine whether TACE increases overall survival (OS) of in patients with liver metastases. The retrospective cohort study included 171 patients with liver metastases diagnosed between 2001 and 2015. OS was compared between the TACE and non-TACE groups after propensity score matching to reduce the effects of selection bias and potential confounders. Multivariate analysis was conducted to confirm the confounding factors with OS. After excluding 43 patients, 128 patients were analysed and among thses 64 patients (50%) were included in the TACE group. In the propensity score matched cohort (42 pairs), the OS was non-significantly longer in the TACE group than in the non-TACE group (p = 0.789). Multivariate analysis revealed that international normalized ratio (INR) (HR 0.058, 95%CI: [0.005, 0.681]; p = 0.023) and Radiofrequency ablation (RFA) (HR 3.054, 95%CI: [1.418, 6.579]; p = 0.004) were independent risk factors for OS in patients with unresectable liver metastases. There were no significant differences in patients with unresectable liver metastases with or without TACE. INR and RFA can significantly affect OS in patients with unresectable liver metastases.