Short term treatment results of local ablation with water-cooled microwave antenna for liver cancer: Comparison with radiofrequency ablation

Outcomes of microwave versus radiofrequency ablation for hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

Studies to date comparing outcomes of microwave ablation (MWA) with radiofrequency ablation (RFA) on patients with hepatocellular carcinoma have yielded conflicting results, with no clear superiority of one technique over the other. The aim of this systematic review and meta-analysis was to compare the efficacy and safety of MWA with RFA.

AIM

To perform a systematic review and meta-analysis comparing the efficacy and safety of MWA with RFA.

METHODS

A systematic literature search was performed using Ovid Medline, Embase, PubMed, Reference Citation Analysis, Cochrane Central and Cochrane Systematic Review databases, and Web of Science. Abstracts and full manuscripts were screened for inclusion utilising predefined inclusion and exclusion criteria comparing outcomes of MWA and RFA. A random-effects model was used for each outcome. Meta-regression analysis was performed to adjust for the difference in follow-up period between the studies. Primary outcome measures included complete ablation (CA) rate, local recurrence rate (LRR), survival [local recurrence-free survival (LRFS), overall survival (OS)] and adverse events.

RESULTS

A total of 42 published studies [34 cohort and 8 randomised controlled trials (RCT)] with 6719 patients fulfilled the selection criteria. There was no significant difference in tumour size between the treatment groups. CA rates between MWA and RFA groups were similar in prospective cohort studies [odds ratio (OR) 0.95, 95% confidence interval (CI) 0.28–3.23] and RCTs (OR 1.18, 95%CI 0.64–2.18). However, retrospective studies reported higher rates with MWA (OR 1.29, 95%CI 1.06–1.57). Retrospective cohort studies reported higher OS (OR 1.54, 95%CI 1.15–2.05 and lower LRR (OR 0.67, 95%CI 0.51–0.87). No difference in terms of LRFS or 30-d mortality was observed between both arms. MWA had an increased rate of adverse respiratory events when compared to RFA (OR 1.99, 95%CI 1.07–3.71, P = 0.03).

CONCLUSION

MWA achieves similar CA rates and as good or better longer-term outcomes in relation to LRR and OS compared to RFA. Apart from an increased rate of respiratory events post procedure, MWA is as safe as RFA.

Evaluation of 3D-CEUS in the Recurrence of Liver Cancer after Radiofrequency Ablation

Background

Radiofrequency ablation (RFA) has the similar curative effects to surgery, but RFA will lead to higher postoperative local recurrence rate. 3D-CEUS is a minimally invasive examination method, which is used to analyze the sensitivity to postoperative recurrence in this study.

Methods

The clinical data of 60 patients with liver cancer admitted to our hospital (February 2018-February 2020) were retrospectively analyzed. All patients were treated with RFA and were followed up with 3D-CEUS, MRI, and enhanced CT examination after surgery. The ROC curve was used to analyze the differences of different examination methods in judging postoperative recurrence.

Results

For the 60 patients, 52 patients (86.7%) had a single lesion and 8 patients (13.3%) had multiple lesions, with a total of 72 lesions. After RFA, 56 lesions (77.8%) were completely inactivated and 16 lesions (22.2%) remained. Totally inactivated lesions were detected as follows: 51 (91.1%) by 3D-CEUS, 42 (75.0%) by MRI, and 50 (89.3%) by enhanced CT. During a 2-year follow-up, a total of 26 recurrent lesions were detected, 24 (92.3%) by 3D-CEUS, 12 (46.2%) by MRI, and 25 (96.2%) by enhanced CT, indicating that the sensitivity of 3D-CEUS and enhanced CT was obviously higher than that of MRI (P < 0.001), without conspicuous difference between sensitivity of 3D-CEUS and enhanced CT (P > 0.05).

Conclusion

As a new imaging examination method based on artificial intelligence, 3D-CEUS has a high sensitivity in patients with liver cancer who underwent RFA, which can effectively judge the recurrence after surgery and should be widely used in practice.

New next-generation microwave thermosphere ablation for small hepatocellular carcinoma

Background/Aims

In July 2017, the EmprintTM next-generation microwave ablation system using thermosphere technology (Covidien, Boulder, CO, USA) was approved for use in Japan. This system can produce a predictable spherical ablation zone at higher temperatures than radiofrequency ablation (RFA). The aim of the present study was to elucidate whether this new microwave thermosphere ablation (MTA) could safely improve outcome compared to RFA, which is the standard of care for small hepatocellular carcinoma (HCC).

Methods

This retrospective study analyzed 513 patients with 630 HCCs (≤3 cm) who were performed by percutaneous RFA (174 patients, 214 HCCs) or MTA (339 patients, 416 HCCs) between January 2016 and March 2020.

Results

Median ablation time was significantly shorter for MTA (240 s) than for RFA (721 s; p<0.001). A significant difference in 3-year local tumor progression rate was evident between the RFA group (22%) and MTA group (8%; p<0.001) Multivariate analysis revealed ablation procedure and tumor diameter as independent factors contributing to local tumor progression (MTA, p<0.001, hazard ratio 0.565, 95% confidence interval 0.437-0.731). In patients with primary HCC, a significant difference in overall survival was evident (RFA vs MTA, 3-year, 77% vs 95%, p=0.029). Ablation procedure and Child-Pugh score were independent factors contributing to survival. The total complication rate was significantly lower for MTA (8%) than for RFA (14%, p<0.05), particularly for bile duct injury (3% vs 9%, respectively; p<0.05).

Conclusions

Next-generation MTA for small HCC could provide safer, more curative treatment in a shorter ablation time than RFA.

Efficacy of microwave ablation versus radiofrequency ablation for hepatocellular carcinoma: a propensity score analysis

Purpose

To evaluate the efficacy and safety of radiofrequency ablation (RFA) and new-generation microwave ablation (MWA) for the treatment of hepatocellular carcinoma (HCC).

Methods

The propensity score matching method was applied to patients with HCC treated with MWA (93 patients) or RFA (156 patients) at a single institution from January 2014 to April 2020. The local tumor progression (LTP), intrahepatic distant recurrence (IDR), and recurrence-free survival (RFS) of the two matched therapies were analyzed using the Kaplan–Meier method. Cox proportional hazard models were used to identify risk factors for LTP and RFS. The therapeutic effects and complications of the two treatments were also compared.

Results

The LTP, IDR, and RFS of MWA and RFA were equivalent (LTP: hazard ratio [HR] = 0.87; 95% confidence interval [95% CI] 0.36- 2.07; P = 0.746, IDR: HR = 1.03; 95% CI 0.61–1.73; P = 0.890, RFS: HR = 1.15; 95% CI 0.69–1.91; P = 0.566). Para-vessel lesions was the only risk factor for LTP, whereas age, previous treatment, Albumin-Bilirubin score, and tumor diameter were risk factors for RFS. On the other hand, the ablation time per nodule (6.79 ± 2.73 and 9.21 ± 4.90 min; P = 0.008) and number of sessions per nodule required to achieve technical success (1.16 ± 0.39 and 1.34 ± 0.57; P = 0.009) were significantly lower in MWA than in RFA. The major complication rate of MWA and RFA was also equivalent.

Conclusion

MWA and RFA have similar therapeutic effects and safety, although MWA has advantages over RFA regarding efficacy, including shorter ablation time and fewer sessions required.

Comparing the Safety and Efficacy of Microwave Ablation Using ThermosphereTM Technology versus Radiofrequency Ablation for Hepatocellular Carcinoma: A Propensity Score-Matched Analysis

Simple Summary

Microwave ablation using Thermosphere^TM technology is a novel locoregional treatment for hepatocellular carcinoma. This study compared the safety and efficacy outcomes of this microwave ablation strategy versus radiofrequency ablation using propensity score-matched analysis. Microwave ablation led to a high rate of curative ablation (94.7%) and a low rate of local recurrence (3.3%), with an overall survival rate of 99.3% at 1 year (recurrence-free survival: 81.1%) and 88.4% at 2 years (recurrence-free survival: 60.5%). There were no significant differences in survival outcomes after microwave and radiofrequency ablation. However, microwave ablation required significantly fewer insertions (1.22 ± 0.49 vs. 1.59 ± 0.94; p < 0.0001). Based on the similar survival outcomes, we recommend microwave ablation using Thermosphere^TM technology for hepatocellular carcinoma with a diameter of >2 cm because of the lower number of insertions.

Abstract

There is limited information regarding the oncological benefits of microwave ablation using Thermosphere^TM technology for hepatocellular carcinoma. This study compared the overall survival and recurrence-free survival outcomes among patients with hepatocellular carcinoma after microwave ablation using Thermosphere^TM technology and after radiofrequency ablation. Between December 2017 and August 2020, 410 patients with hepatocellular carcinoma (a single lesion that was ≤5 cm or ≤3 lesions that were ≤3 cm) underwent ablation at our institution. Propensity score matching identified 150 matched pairs of patients with well-balanced characteristics. The microwave ablation and radiofrequency ablation groups had similar overall survival rates at 1 year (99.3% vs. 98.2%) and at 2 years (88.4% vs. 87.5%) (p = 0.728), as well as similar recurrence-free survival rates at 1 year (81.1% vs. 76.2%) and at 2 years (60.5% vs. 62.1%) (p = 0.492). However, the microwave ablation group had a significantly lower mean number of total insertions (1.22 ± 0.49 vs. 1.59 ± 0.94; p < 0.0001). This retrospective study revealed no significant differences in the overall survival and recurrence-free survival outcomes after microwave ablation or radiofrequency ablation. However, we recommend microwave ablation for hepatocellular carcinoma tumors with a diameter of >2 cm based on the lower number of insertions.

Combination therapy by transarterial injection of miriplatin-iodized oil suspension with radiofrequency ablation (RFA) versus microwave ablation (MWA) for small hepatocellular carcinoma: a comparison of therapeutic efficacy

PURPOSE

To compare the technical efficacy and complications of the transarterial injection of a miriplatin-iodized oil suspension combined with radiofrequency ablation (RFA) or microwave ablation (MWA) in the treatment of small hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

This retrospective study included 123 HCCs in 101 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and RFA (MPT-RFA) (maximum diameter: 1.5 [Formula: see text] 0.5 cm, range: 0.6-3.0 cm) and 68 HCCs in 49 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and MWA (MPT-MWA) (maximum diameter: 1.6 [Formula: see text] 0.7 cm, range: 0.5-3.0 cm). Technical success was defined as the achievement of an ablative margin of at least 5 mm for each tumor. Technical success, complications, and local tumor progression were compared between the two groups.

RESULTS

The initial technical success rate was significantly higher with MPT-MWA (94.1%) than with MPT-RFA (76.4%; P = 0.003). The number of treatment sessions per nodule was significantly lower with MPT-MWA (1.1) than with MPT-RFA (1.3) (P = 0.004). The major complication rates were similar with MPT-RFA (5.8%) and MPT-MWA (2.7%) (P = 0.391). The one-year local tumor progression rate was similar between MPT-RFA (0%) and MPT-MWA (0%) (P = 0.73).

CONCLUSION

MPT-MWA may have improved therapeutic efficiency in the treatment of small HCCs.

Microwave ablation of liver cancer: An updated review

The treatment methods for early liver cancer include surgical resection, liver transplantation, and local ablation. Among them, microwave ablation (MWA) is widely used in clinical practice because of its outstanding advantages, such as minimal invasiveness, radical curative effect, short treatment time, few complications, and no heat-sink effect, especially for the treatment of tumors adjacent to major vessels and hepatic metastases. However, MWA also has limitations such as unpredictable size and shape of the ablation area. This review systematically illustrates the effectiveness and safety of MWA in the treatment of liver cancer. Meanwhile, the relative superiority of the new generation of MWA is discussed, with an aim to provide reference for MWA of liver cancer.