Combination therapy of three-dimensional (3D) visualisation operative treatment planning system and US-guided percutaneous microwave ablation in larger renal cell carcinomas (D ≥ 4 cm): preliminary results

Value of the three-dimensional visualization ablation planning system in ultrasound-guided percutaneous microwave ablation for malignant adrenal tumors: A clinical comparative study

OBJECTIVE

We aimed to assess the efficacy and safety of the three-dimensional visualization ablation planning system (3DVAPS) in ultrasound-guided percutaneous microwave ablation (US-PMWA) for malignant adrenal tumors (MATs).

METHODS

A retrospective analysis was conducted on a cohort of 62 unilateral MAT cases from March 2011 to November 2022. There were a total of 62 lesions, with a mean maximum diameter of 5.4 ± 2.7 cm (range, 1.4-15.7 cm). The patients were categorized into the following, based on the pre-operative planning method: 3D planning (n = 32) and 2D planning (n = 30) groups. A comparative analysis was performed on various parameters, including ablation techniques, tumor-related prognosis, and incidence of complications. This analysis encompassed indicators, such as overall survival (OS) rate and local tumor progression (LTP), among others.

RESULTS

The median follow-up period was 30 months (range, 3-84 months). Notably, compared with the 2D planning group, the 3D planning group exhibited significant disparities in the number of punctures (P = 0.035) and incidence of complications (P = 0.029) and had no significant difference in the OS ( P > 0.05) but had a significantly lower LTP rate (6.2% vs. 23.3%, P = 0.033). In the 3D planning group, the sub-group with a tumor diameter of < 5 cm exhibited a significantly less number of punctures ( P = 0.039), lower input energy ( P = 0.002), and a shorter ablation time ( P = 0.001), compared with the sub-group with a tumor diameter of ≥ 5 cm, but there was no significant difference in the LTP and OS rates between the two sub-groups ( P > 0.05).

CONCLUSIONS

The use of 3DVAPS in US-PMWA of MATs was advantageous, especially in lesions with a diameter of ≥ 5 cm. It can help in developing more rational surgical plans, reducing the incidence of complications, and extending the local recurrence-free survival time of patients and can add a certain value for precise treatment and expand the indications for ablation.

Microwave ablation of 105 T1 renal tumors: technique efficacy with a mean follow-up of two years

BACKGROUND

Thermal ablation (TA) with radiofrequency (RFA) or cryoablation (CA) are established treatments for small renal masses (≤4 cm). Microwave ablation (MWA) has several potential benefits (decreased ablation time, less susceptibility to heat-sink, higher lesion temperatures than RFA) but is still considered experimental considering the available small-sample studies with short follow-up.

PURPOSE

To evaluate technique efficacy and complications of our initial experience of renal tumors treated using percutaneous MWA with a curative intent.

MATERIAL AND METHODS

A total of 105 renal tumors (in 93 patients) were treated between April 2014 and August 2017. MWA was performed percutaneously with computed tomography (CT) guidance under conscious sedation (n=82) or full anesthesia. Patients were followed with contrast-enhanced CT scans at six months and yearly thereafter for a minimum of five years. The mean follow-up time was 2.1 years. The percentage of tumors completely ablated in a single session (primary efficacy rate) and those successfully treated after repeat ablation (secondary efficacy rate) were recorded. Patient and tumor characteristics as well as complications were collected retrospectively.

RESULTS

The median patient age was 70 years and median tumor size was 25 mm. Primary efficacy rate was 96.2% (101/105 tumors). After including two residual tumors for a second ablation session, secondary efficacy was 97.1% (102/105). Periprocedural complications were found in 5.2% (5/95) sessions: four Clavien-Dindo I and one Clavien-Dindo IIIa. One postprocedural Clavien-Dindo II complication was found.

CONCLUSION

MWA has high efficacy rates and few complications compared to other TA methods at a mean follow-up of two years.

Dynamic changes in liver volume calculated using a three-dimensional visualization system after microwave ablation of hepatocellular carcinomas

OBJECTIVES

To investigate the changes in liver volume and function after microwave ablation (MWA) of hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

We retrospectively analyzed 76 patients with 106 nodules who underwent MWA for HCCs ≤5 cm between January 2015 and September 2017. Liver and ablation volumes were calculated using a three-dimensional visualization system on MRI. Multiple regression analysis was used to estimate the association between the ablation volume and liver volume changes. Deformable image registration (DIR) was performed to confirm the influence of liver volume changes on curative effect evaluation after ablation.

RESULTS

The initial liver and tumor volumes were 1262.1±259.91 cm³ (range: 864.9∼1966.8) and 2.5 cm³ (interquartile range [IQR]: 1.3∼8.8), respectively. Compared to the initial liver volumes, the entire live volume (ELV) increased by 10.1%±8.93% (range: -4.9%∼46.68%) on the 3rd day after ablation. Subsequently, it recovered to initial level at the 3rd month and maintained its level during the 1-year follow-up. The median total ablation volume was 34.9 cm³ (IQR: 20.4∼65.4) on the 3rd day after ablation, which decreased by 71.2% (IQR: 57.4%∼78.1%) one year after ablation. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (T-Bil) peaked within 3 days after MWA and recovered to normal within 1 month. The ablation volume proportion of the ELV was an independent risk factor for the increase in the ELV and AST, ALT, and T-Bil levels within 3 days after ablation. When DIR was conducted to fuse ablation zone and tumor, the reshaped tumor volumes were enlarged by 40% because of the increase in ELV.

CONCLUSIONS

MWA of HCCs based on the Milan criteria could induce temporary increases in ELV and RLV within 3 days after ablation, but both parameters recovered to initial levels 3 months after ablation. This indicates that MWA of early-stage HCCs would not lead to liver volume loss and could potentially protect liver function. The liver cannot be treated as an incompressible organ after ablation, and the appropriate deformation constraint should be designed for DIR to evaluate ablation margin accurately. This article is protected by copyright. All rights reserved.

Percutaneous microwave ablation of renal cell carcinoma: practice guidelines of the ultrasound committee of Chinese medical association, interventional oncology committee of Chinese research hospital association

Imaging-guided percutaneous microwave ablation (MWA) with high thermal efficiency comprises rapid, successful management of small renal cell carcinomas (RCCs) in selected patients. Ultrasound Committee of Chinese Medical Association, Interventional Oncology Committee of Chinese Research Hospital Association developed evidence-based guidelines for MWA of RCCs after systematically reviewing the 1969-2019 literature. Systematic reviews, meta-analyses, randomized controlled trials, cohort, and case-control studies reporting MWA of RCCs were included and levels of evidence assessed. Altogether, 146 articles were identified, of which 35 reported percutaneous MWA for T1a RCCs and 5 articles for T1b RCCs. Guidelines were established based on indications, techniques, safety, and effectiveness of MWA for RCCs, with the goal of standardizing imaging-guided percutaneous MWA treatment of RCCs. Key points Microwave ablation is recommended for managing small renal cell carcinoma in selected patients. Imaging protocols are tailored based on the procedural plan, guidance, and evaluation. Patient's selection evaluation, updated technique information, clinical efficacy, and complications are recommended to standardize management. A joint task force (multidisciplinary team) summarized the key elements of the standardized report.

Microwave ablation assisted by three-dimensional visualization system as local therapy for relapsed hepatoblastoma: a small pilot study

PURPOSE

We aimed to explore the feasibility of microwave ablation (MWA) assisted by three-dimensional visualization system for relapsed HB in children.

METHODS

From August 2014 to February 2017, five patients with relapsed HB were enrolled. A total of 12 liver tumors were treated with MWA assisted by a three-dimensional visualization system. Follow-up data were obtained in all patients. The residual liver volume, local tumor progression, new intrahepatic tumors, survival outcome, and complications were analyzed.

RESULTS

All tumors were completely ablated in a single session. The mean ablation time per tumor was 9.7 ± 8.6 min, and the median ablation/liver volume ratio was 2.37%. No local tumor progression was observed during a follow-up period of 9-39 months. All patients were still alive at the end of the follow-up. The median progression-free survival time after ablation was 9 months, and the median survival time after ablation was 12 months. No other complications were observed except for fever.

CONCLUSIONS

MWA assisted by three-dimensional visualization system appears to be a safe and feasible local treatment for recurrent HB in pediatric patients.

The value of 3D visualization operative planning system in ultrasound-guided percutaneous microwave ablation for large hepatic hemangiomas: a clinical comparative study

Background

To evaluate the value of a three dimension (3D)visualization operative planning system in ultrasound-guided percutaneous microwave ablation (US-PMWA) for large hepatic hemangiomas (LHHs).

Methods

Fifty-eight patients with LHHs were divided into 3D and 2D groups. The therapeutic efficacy was assessed by contrast-enhanced imaging during follow-up. Hepatic and renal function were examined. The complete ablation, tumor volume shrinkage, and complication rates were analyzed.

Results

The ablation time and energy of the 3D group were lower than those of the 2D group (1152.0 ± 403.9 s vs. 1379.7 ± 375.8 s and 87,407.2.9 ± 50,387.0 J vs. 117,775.8 ± 46,245.6 J, P = 0.031 and 0.021, respectively). The 3D group had a higher complete ablation rate than the 2D group (97.7 ± 2.4% vs. 94.5 ± 3.7%, P < 0.001). The incidence of hemoglobinuria after ablation in the 3D group was lower than that in the 2D group (32.0% vs. 57.6%, P = 0.047). The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and creatinine (Cre) after ablation in the 3D group were lower than those in the 2D group (126.7 ± 56.4 U/L vs. 210.9 ± 96.2 U/L, P < 0.001; 141.0 ± 60.8 U/L vs. 211.4 ± 90.0 U/L, P = 0.001; 57.3 ± 17.6 U/L vs. 80.8 ± 41.9 U/L, P = 0.010; and 66.6 ± 16.6 mmol/L vs. 84.5 ± 39.6 mmol/L, P = 0.037, respectively). There were no significant differences in antenna insertion and the volume reduction rate between the groups. One patient developed acute kidney injury shortly after ablation in the 2D group and recovered after hemodialysis. No other severe complications occurred during the follow-up period.

Conclusions

The 3D visualization operative planning system has a relatively high clinical application value in providing scientific, reasonable, quantifiable, and individualized therapy for LHHs by US-PMWA.

The clinical efficacy of ultrasound-guided percutaneous microwave ablation for rib metastases with severe intractable pain: a preliminary clinical study

Purpose: To retrospectively evaluate the clinical efficacy of ultrasound-guided percutaneous microwave ablation (US-PMWA) for patients with rib metastases that caused severe intractable pain.

Materials and methods: From Jan 2016 to Apr 2018, 9 rib metastases from 7 solid tumor patients were treated with US-PMWA. The visual analogue scale (VAS), daily opiate intake doses, local tumor control and complications were recorded and analyzed.

Results: The follow-up period ranged from 6 to 33 months (median: 16 months). The procedures were successfully performed in all of the patients by one ablation. The ablation power ranged from 30 to 60 W, and the ablation time was 610.0±317.5 s. The mean preablation VAS pain score was 8.1±0.7, whereas the mean VAS pain score at 72 h postablation was 3.3±0.5 (P<0.001). All of the patients needed to apply oral and/or intravenous injection opiates to relieve severe intractable pain before ablation, with daily opiate intake doses of 61.4±30.8 mg. After ablation, five patients did not need to apply any opiate treatments 72 h after ablation, and only two patients needed oral opiates (daily opiate intake doses: 30 mg and 20 mg). Recurrence was detected in three lesions at 6, 11 and 9 months after ablation, with the maximum diameter observed being more than 4 cm. All of the patients were alive during the follow-up period. No minor or major complications occurred.

Conclusion: US-PMWA appears to be feasible, convenient, safe and effective in the palliative management of refractory pain caused by rib metastases. This treatment can improve the quality of life of patients and may also achieve promising local control of tumors.

Efficacy and Safety of Microwave Ablation for Malignant Renal Tumors: An Updated Systematic Review and Meta-Analysis of the Literature Since 2012

Objective

To systematically determine the treatment outcomes of percutaneous microwave ablation (MWA) in patients with malignant renal tumor.

Materials and Methods

Original studies that reported the clinical outcomes of MWA in patients with malignant renal tumors were identified in MEDLINE and EMBASE from 2012 to June 30, 2017. Inverse variance and random-effects models were used to evaluate and acquire meta-analytic summary estimates of various clinical outcomes, including technical outcomes (technical success rate [TSR] and technical efficacy rate [TER]), oncologic outcomes (local tumor recurrence rate [LRR], cancer-specific survival rate [CSSR], and overall survival rate [OSR]), and complications.

Results

Among the 145 articles screened, 13 articles including 567 patients carrying 616 malignant renal tumors were included in the meta-analysis. The meta-analytic pooled TSR and TER were 97.3% (95% confidence interval, 94.3-99.4%; I² = 0.0%) and 97.6% (95.0-99.4%, I² = 48.5%), respectively. The meta-analytic pooled LRR was 2.1% (0.3-4.7%, I² = 54.1%). At 1-, 2-, 3-, and 5-year follow-up time points, the meta-analytic pooled CSSRs were 99.1% (97.2-100.0%; I² = 0.0%), 98.4% (95.1-100.0%; I² = 31.2%), 97.6% (93.4-99.9%; I² = 52.3%), and 96.9% (93.3-99.2%; I² = 0.0%) respectively, while the OSRs were 98.3% (96.1-99.8%; I² = 0.0%), 94.9% (91.7-97.5%; I² = 0.0%), 86.8% (81.9-91.1%; I² = 22.1%), and 81.9% (75.4-87.6%; I² = 0.0%). In terms of major complications, a 1.8% (0.6-3.3%; I² = 0.0%) rate of meta-analytic pooled incidence was found.

Conclusion

Microwave ablation showed favorable technical and oncologic outcomes with a low incidence of major complications. Hence, image-guided percutaneous MWA can be considered as a safe and effective treatment for malignant renal tumors.