Status and advancement of microwave ablation in China

Development and validation of a prognostic nomogram for early hepatocellular carcinoma treated with microwave ablation

Objective

An effective model for risk stratification and prognostic assessment of early hepatocellular carcinoma (HCC) patients following microwave ablation (MWA) is lacking in clinical practice. The aim of this study is to develop and validate a prognostic model specifically for these patients.

Methods

Between January 2008 and December 2018, 345 treatment-naïve patients with HCC conforming to the Milan criteria who underwent MWA were enrolled and randomly assigned to the training (n=209) and validation (n=136) cohorts. The nomogram model was constructed based on the predictors assessed by the multivariate Cox proportional hazards model and validated. Predictive accuracy and discriminative ability were further evaluated and compared with other prognostic models.

Results

After a median follow-up of 59.0 months, 52.5% (187/356) of the patients had died. Prognostic factors for overall survival (OS) were α-fetoprotein (AFP), albumin-bilirubin (ALBI) score, platelets, and ablation margins, which generated the nomograms. The nomogram model consistently achieved good calibration and discriminatory ability with a concordance index of 0.64 (95% confidence interval (CI): 0.59-0.69) and 0.69 (95% CI: 0.63-0.75) in both the training and validation cohorts. The performance of the nomogram model also outperformed other prognostic models. By using the nomogram model, the patient population could be correctly divided into low- and high-risk strata presenting significantly different median OS of 105.0 (95% CI: 84.1-125.9) months, and 45.0 (95% CI: 28.0-62.0) months, respectively.

Conclusion

The nomogram model based on AFP, PLT, ablation margins, and ALBI score was a simple visualization model that could stratify patients with early-stage HCC after MWA and predict individualized long-term survival with favorable performance.

Computed tomography-guided microwave ablation therapy for pediatric adrenal neuroblastoma with lung nodule a case report

BACKGROUND

Solid lung lesions are common in clinical practice, and percutaneous thermal ablation has been shown to be an effective treatment for these lesions. While computed tomography (CT)-guided microwave ablation (MWA) therapy is frequently used for adult solid lesions, it is rarely considered for pediatric cases.

CASE PRESENTATION

A case of an 8-year-old child with adrenal neuroblastoma and a left upper lung mass. The child successfully underwent lung mass ablation and experienced a long-term progression-free period with good recovery and no recurrence.

CONCLUSIONS

This case suggests that MWA could be a valuable addition to existing treatment options for solid lesions in children.

Cryoablation versus microwave ablation in the treatment of hepatocellular carcinoma: A Systematic Review and meta-analysis

To evaluate the efficacy and safety of cryoablation (CRA) versus microwave ablation (MWA) for hepatocellular carcinoma (HCC). The PubMed, Embase, Cochrane Library, CNKI, Wan Fang and VIP databases were searched to obtain all related studies on CRA and MWA from the inception dates to July 2022. The Meta-analysis was performed by the RevMan5.3 software. Five studies comparing CRA with MWA were eligible and 470 HCC patients were included in the analysis. No statistically significant differences in complete ablation rate (OR = 1.17, 95 % CI: 0.36-3.79, P > 0.05), local recurrence rate (OR = 0.25, 95 % CI: 0.05-1.29, P = 0.10), 1-year survival rate (OR = 2.07, 95 % CI: 0.89-4.79, P > 0.05) and postoperative decreased value of AFP (MD = -1.63, 95 % CI: -83.13-79.87, P > 0.05) were observed; however, CRA was associated with a significantly lower major complication rate (OR = 0.06, 95 % CI: 0.01-0.31, P < 0.05) compared with MWA. CRA had comparable outcomes to MWA in terms of complete ablation, local recurrence, 1-year survival and postoperative reduced AFP, meanwhile, CRA demonstrated favorable safety, and CRA may be a recommended ablation treatment for HCC.

Combined preoperative denosumab and adjuvant microwave ablation for high-risk giant cell tumor of bone: a retrospective study in a single center

BACKGROUND

Giant cell tumor of bone (GCTB) is a locally aggressive neoplasm with a high propensity for recurrence following intralesional curettage. The introduction of denosumab, a RANKL inhibitor, has shown potential in facilitating joint-sparing surgery. However, concerns exist regarding its impact on local recurrence rates. This study aimed to evaluate the efficacy and safety of combined preoperative denosumab with adjuvant microwave ablation (MWA) for the treatment of high-risk GCTB.

METHODS

We conducted a retrospective review of 19 patients with high-risk GCTB who underwent preoperative denosumab treatment followed by curettage and adjuvant MWA. The primary outcome measure was the local recurrence rate, with secondary outcomes including functional status assessed by the Musculoskeletal Tumor Society (MSTS) score and safety profile of the treatment.

RESULTS

In this retrospective analysis, we evaluated the outcomes of 19 patients with high-risk GCTB treated with preoperative denosumab and adjuvant MWA. The median follow-up duration was 33.1 months, 3 patients (15.8%) experienced local recurrence at a median of 21.6 months postoperatively and the local recurrence-free survival was 81.2% at two years. Notably, no patient developed lung metastasis, and all recurrences were successfully managed with repeat curettage and MWA, with a mean MSTS score of 27.3. No patient required joint replacement due to tumor recurrence, resulting in a 100% joint preservation rate.

CONCLUSION

The combination of preoperative denosumab and adjuvant MWA is a feasible and effective strategy for the management of high-risk GCTB, providing effective local control with preserved joint function. This approach may offer a surgical alternative for young patients where joint preservation is paramount.

Early versus Late Recurrence of Hepatocellular Carcinoma after Microwave Ablation: Patterns, Treatments, and Post-Recurrence Survival

INTRODUCTION

Recurrence after microwave ablation (MWA) has not been extensively studied. We aimed to investigate the patterns, treatments, and survival of patients with hepatocellular carcinoma (HCC) who experienced early and late recurrence after MWA.

METHODS

This retrospective study included patients with HCC recurrence after MWA as the initial treatment from January 2008 to December 2021. Recurrence patterns, treatments, and outcomes between patients with early and late HCC recurrence were compared. Prognostic factors of post-recurrence survival (PRS) were identified by multivariable Cox regression analyses.

RESULTS

Among 222 patients, 128 developed early recurrence (≤2 years after MWA) and 94 had late recurrence (>2 years). Majority of the recurrent HCC were intrahepatic-only recurrence, within the Milan criteria, and received potentially curative treatment. No significant differences in the recurrence patterns, vascular invasion, tumor staging, post-recurrence treatments, or median PRS (35.0 vs. 33.0 months, p = 0.523) were identified between patients with early and late recurrence. Multivariable analyses suggested that multiple tumor number (hazard ratio [HR]: 1.54; 95% CI: 1.03-2.30, p = 0.038), extrahepatic recurrence (HR: 2.14, 95% CI: 1.16-3.92, p = 0.015), vascular invasion (HR: 2.37, 95% CI: 1.18-4.76, p = 0.038), and higher ALBI grade (HR: 2.18, 95% CI: 1.54-3.08, p < 0.001) were independent risk factors of worse PRS, while curative treatment after recurrence (HR: 0.59, 95% CI: 0.38-0.92, p = 0.020) was associated with better PRS.

CONCLUSIONS

No differences in recurrence patterns, post-recurrence treatments, or PRS were found between HCC patients with early and late recurrence following MWA. Tumor burden and patients' liver function reserve should be considered to decide the optimal post-recurrence treatment after MWA.

Prediction of local tumor progression after microwave ablation for early-stage hepatocellular carcinoma with machine learning

Objectives

Local tumor progression (LTP) is a major constraint for achieving technical success in microwave ablation (MWA) for the treatment of early-stage hepatocellular carcinoma (EHCC). This study aims to develop machine learning (ML)-based predictive models for LTP after initial MWA in EHCC.

Materials and Methods

A total of 607 treatment-naïve EHCC patients (mean ± standard deviation [SD] age, 57.4 ± 10.8 years) with 934 tumors according to the Milan criteria who subsequently underwent MWA between August 2009 and January 2016 were enrolled. During the same period, 299 patients were assigned to the external validation datasets. To identify risk factors of LTP after MWA, clinicopathological data and ablation parameters were collected. Predictive models were developed according to 21 variables using four ML algorithms and evaluated based on the area under the receiver operating characteristic curve (AUC) with 95% confidence intervals (CIs).

Results

After a median follow-up time of 28.7 months (range, 7.6-110.5 months), 6.9% (42/607) of patients had confirmed LTP in the training dataset. The tumor size and number were significantly related to LTP. The AUCs of the four models ranged from 0.791 to 0.898. The best performance (AUC: 0.898, 95% CI: [0.842 0.954]; SD: 0.028) occurred when nine variables were introduced to the CatBoost algorithm. According to the feature selection algorithms, the top six predictors were tumor number, albumin and alpha-fetoprotein, tumor size, age, and international normalized ratio.

Conclusions

Out of the four ML models, the CatBoost model performed best, and reasonable and precise ablation protocols will significantly reduce LTP.

Microwave in situ inactivation in the treatment of bone giant cell tumor: a mid-term descriptive study

AIM

To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB).

METHODS

This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results.

RESULTS

All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis.

CONCLUSIONS

The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone.

LEVEL OF EVIDENCE

IV: case series.

Ultrasound-guided microwave ablation of soft tissue venous malformations

OBJECTIVE

To assess the feasibility, safety, and effectiveness of microwave ablation (MWA) for soft tissue venous malformations (VMs).

METHODS

We retrospectively analyzed 20 patients with symptomatic VMs in the lower extremities and trunk. MWA was performed in all 20 patients. Contrast-enhanced ultrasound (CEUS) was performed immediately and 1 month after ablation. The data on the complete ablation rate, symptom improvement, and patient satisfaction were collected. Follow-up examinations began 1 month after ablation and continued for 2 to 19 months.

RESULTS

MWA was performed on 20 patients. The overall complete ablation rate was 75% (15/20). The complete ablation rate for the 11 patients with lesions <5 cm and the 9 patients with lesions >5 cm were 100% (11/11) and 44% (4/9), respectively. The complete ablation rate for the 14 patients with localized and 6 patients with extensive lesions was 93% (13/14) and 33% (2/6), respectively. Five patients had experienced incomplete ablation; 1 had a lesion >5 cm with ectopic drainage vessels, one had multiple lesions adherent to blood vessels and nerves, and three had large and extensive lesions. Thirteen patients had experienced significant improvements in clinical symptoms; 6 showed slight improvement; and 1 showed no change in symptoms. No complications or recurrences were observed. All 20 patients were satisfied with the therapeutic effect (100%). Twelve patients were significantly satisfied and 8 were slightly satisfied.

CONCLUSIONS

MWA with ultrasound guidance is a safe, effective, and minimally invasive therapy for symptomatic soft tissue VMs and may be a promising approach in the future.

Role of interventional oncology for treatment of liver metastases: evidence based best practice

The presence of liver metastases is associated with a poor prognosis in many cancer diseases. Multiple studies during the last decades aimed to find out the best multimodal therapy to achieve an ideal, safe and highly effective treatment. In addition to established therapies such as systemic therapy, surgery and radiation therapy, interventional oncology with thermal ablation, transarterial chemoembolisation and radioembolisation, is becoming the fourth pillar of cancer therapies and is part of a personalised treatments' strategy. This review informs about the most popular currently performed interventional oncological treatments in patients with liver metastases.

Study on the Microwave Ablation Effect of Inflated Porcine Lung

(1) Background: Microwave ablation (MWA) has an efficient killing effect on primary and metastatic lung cancer. However, the treatment effect will be affected by the air in the lung, which makes it very difficult to accurately predict and control the ablation area; (2) Methods: In this paper, in vitro experiments combined with simulations are used to study the microwave ablation area of inflated porcine lung. The in vitro experiment is divided into inflated group and deflated group, combined with different ablation power (40 W, 50 W, 60 W) and ablation time (100 s, 200 s, 300 s) for experiment, each power and time combination are repeated five times. A total of 90 ablation experiments were performed. The simulation experiment uses COMSOL Multiphysics software to simulate the microwave ablation area of the inflated lung; (3) Results and Conclusions: When the ablation power is 40 W, 50 W, and 60 W, the average long diameter of the deflated group are 20.8–30.9%, 7.6–22.6%, 10.4–19.8% larger than those of the inflated group, respectively; the average short diameter of the deflated group is 24.5–41.4%, 31.6–45.7%, 27.3–42.9% larger than that of the inflated group. The results show that the ablation area of inflated lung is smaller than deflated lung, which is mainly due to the smaller ablation short diameter.

Robotic laser position versus freehand in CT-guided percutaneous microwave ablation for single hepatocellular carcinoma (diameter < 3 cm): a preliminary study

PURPOSE

To compare the accuracy and safety of robotic laser position (RLP) versus freehand for antenna CT-guided microwave ablation (MWA) of single hepatocellular carcinoma (HCC) (diameter < 3 cm).

MATERIALS AND METHODS

This retrospective study was conducted between May 2020 and June 2021. A total of 40 patients with early HCC who underwent CT-guided MWA were divided into two groups: a freehand group (n = 20) and a RLP group (n = 20). Based on in-plane and out-of-plane data, the actual puncture point error (APPE), number of repositioning procedures, and operative duration were compared using the Mann-Whitney U test. Ablation-related complications were compared using the Chi-squared test.

RESULTS

The mean diameter of HCC patients who received MWA was 2.4 ± 0.5 cm. For in-plane APPE, APPE was comparable between the two groups (p = 0.299). However, for the out-of-plane position, the APPE in the freehand group was higher than that in the RLP group (p = 0.027). The number of repositioning procedures was 0 (range, 0-0) for RLP-guided procedures and 3 (range, 2-5) for freehand procedures, showing a statistically significant difference between the two groups (p < 0.001). The mean operative duration for freehand procedures was 39 min, compared with 26 min for RLP-guided procedures, showing a significant difference (p = 0.013). No deaths or major complications were directly related to MWA. Minor complications in the freehand group were comparable with those in the RLP group (p = 0.313).

CONCLUSION

RLP guidance significantly reduces the number of antenna repositioning procedures in MWA and improves puncture accuracy for target HCC out-of-plane. In addition, the operative duration of robotic guidance was shorter than that of freehand guidance.

Hyperthermia ablation combined with transarterial chemoembolization versus monotherapy for hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIMS

The existing evidence has indicated that hyperthermia ablation (HA) and HA combined with transarterial chemoembolization (HATACE) are the optimal alternative to surgical resection for patients with hepatocellular carcinoma (HCC) in the COVID-19 crisis. However, the evidence for decision-making is lacking in terms of comparison between HA and HATACE. Herein, a comprehensive evaluation was performed to compare the efficacy and safety of HATACE with monotherapy.

MATERIALS AND METHODS

Worldwide studies were collected to evaluate the HATACE regimen for HCC due to the practical need for global extrapolation of applicative population. Meta-analyses were performed using the RevMan 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

Thirty-six studies involving a large sample of 5036 patients were included finally. Compared with HA alone, HATACE produced the advantage of 5-year overall survival (OS) rate (OR:1.90; 95%CI:1.46,2.46; p < 0.05) without increasing toxicity (p ≥ 0.05). Compared with TACE alone, HATACE was associated with superior 5-year OS rate (OR:3.54; 95%CI:1.96,6.37; p < 0.05) and significantly reduced the incidences of severe liver damage (OR:0.32; 95%CI:0.11,0.96; p < 0.05) and ascites (OR:0.42; 95%CI:0.20,0.88; p < 0.05). Subgroup analysis results of small (≤3 cm) HCC revealed that there were no significant differences between the HATACE group and HA monotherapy group in regard to the OS rates (p ≥ 0.05).

CONCLUSIONS

Compared with TACE alone, HATACE was more effective and safe for HCC. Compared with HA alone, HATACE was more effective for non-small-sized (>3 cm) HCC with comparable safety. However, the survival benefit of adjuvant TACE in HATACE regimen was not found for the patients with small (≤3 cm) HCC.

Nomograms to predict survival outcomes after microwave ablation in elderly patients (>65 years old) with early-stage hepatocellular carcinoma

Objectives: To develop and validate the nomograms to predict survival outcomes after microwave ablation (MWA) in elderly patients(>65 years old) with early-stage hepatocellular carcinoma (EHCC).Methods: This retrospective study was approved by the institutional review board. A total of 265 EHCC patients (76 females, 189 males; average age 71.4 years ± 5.4 [standard deviation]) with 345 nodules subsequently underwent MWA from April 2006 to October 2019. Baseline characteristics were collected to identify the risk factors for the determination of survival outcomes after MWA. The nomograms were based on prognostic factors for overall survival (OS) and recurrence-free survival (RFS) from the multivariate Cox proportional hazards model and validated in external cohorts from another two institutions (n = 130). The nomograms were assessed for their predictive accuracy using Harrell's concordance index (C-index).Results: After a median follow-up time of 28.6 months, 29.8% (79/265) of the patients died, and 54.3% (144/265) of the patients experienced recurrence in the training set. The OS nomogram was developed based on the hepatitis B virus (HBV) presence, α-fetoprotein (AFP), and albumin, with a C-index of 0.757 (95% confidence interval [CI]: 0.645, 0.789).The scores of the nomogram ranged from 0 to 24. The RFS nomogram was developed based on tumor number, abutting major vessels and platelets, with a C-index of 0.733 (CI: 0.672, 0.774). The likelihood of 3- and 5-year OS and RFS were consistent between clinical observations and nomogram predictions in external cohorts.Conclusions: The nomogram models can be useful in determining the risk of OS and RFS in elderly patients with EHCC after MWA, which can guide individual patient management.Key pointsMWA is an effective and feasible treatment for elderly patients with EHCC and can improve survival outcomes.A calibrated and objective nomogram model for the prediction of survival outcomes in elderly patients (>65 years old) may guide patient selection and MWA treatment.Older age was not deemed to be a risk factor for survival outcomes when the elderly patients with EHCC underwent MWA.

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.

Applications of Microwave Energy in Medicine

Microwaves are a highly utilized electromagnetic wave, used across a range of industries including food processing, communications, in the development of novel medical treatments and biosensor diagnostics. Microwaves have known thermal interactions and theorized non-thermal interactions with living matter; however, there is significant debate as to the mechanisms of action behind these interactions and the potential benefits and limitations of their use. This review summarizes the current knowledge surrounding the implementation of microwave technologies within the medical industry.

Toward a clinical real time tissue ablation technology: combining electroporation and electrolysis (E2)

Background

Percutaneous image-guided tissue ablation (IGA) plays a growing role in the clinical management of solid malignancies. Electroporation is used for IGA in several modalities: irreversible electroporation (IRE), and reversible electroporation with chemotoxic drugs, called electrochemotherapy (ECT). It was shown that the combination of electrolysis and electroporation—E2—affords tissue ablation with greater efficiency, that is, lower voltages, lower energy and shorter procedure times than IRE and without the need for chemotoxic additives as in ECT.

Methods

A new E2 waveform was designed that delivers optimal doses of electroporation and electrolysis in a single waveform. A series of experiments were performed in the liver of pigs to evaluate E2 in the context of clinical applications. The goal was to find initial parameter boundaries in terms of electrical field, pulse duration and charge as well as tissue behavior to enable real time tissue ablation of clinically relevant volumes.

Results

Histological results show that a single several hundred millisecond long E2 waveform can ablate large volume of tissue at relatively low voltages while preserving the integrity of large blood vessels and lumen structures in the ablation zone without the use of chemotoxic drugs or paralyzing drugs during anesthesia. This could translate clinically into much shorter treatment times and ease of use compared to other techniques that are currently applied.

Percutaneous Microwave Ablation versus Laparoscopic Partial Nephrectomy for cT1a Renal Cell Carcinoma: A Propensity-matched Cohort Study of 1955 Patients

Background Percutaneous microwave ablation (MWA) and laparoscopic partial nephrectomy (LPN) are two modalities indicated for early-stage renal cell carcinoma (RCC) with low extent of invasion. Purpose To compare the long-term results of percutaneous MWA and LPN in the treatment of cT1a RCC. Materials and Methods This retrospective study included 1955 patients with cT1a RCC treated with percutaneous MWA or LPN between April 2006 and November 2017. Propensity score matching was used. Oncologic outcomes were analyzed by using the Fine-and-Gray competing risk models. Results A total of 185 patients underwent percutaneous MWA (mean age, 63.2 years ± 15.2 [standard deviation]) and 1770 underwent LPN (mean age, 50.9 years ± 13.2). During the follow-up (median, 40.6 months), after propensity score matching, no difference was observed between local tumor progression (3.2% vs 0.5%, P = .10), cancer-specific survival (2.2% vs 3.8%, P = .24), and distant metastases (4.3% vs 4.3%, P = .76). Patients who underwent percutaneous MWA had worse overall survival (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.7; P = .049 vs LPN) and disease-free survival (82.9% vs 91.4%, P = .003). Percutaneous MWA led to smaller drop in estimated glomerular filtration rate at discharge (6.2% vs 16.4%, P < .001), smaller estimated blood loss (4.5 mL ± 1.3 vs 54.2 mL ± 69.2), lower cost ($3150 ± 2970 vs $6045 ± 1860 U.S. dollars), shorter operative time (0.5 minute ± 0.1 vs 1.8 minutes ± 0.6), and shorter postoperative hospitalization time (5.1 days ± 2.6 vs 6.9 days ± 2.8) (all P < .001 vs LPN). There were fewer cases of fever in the percutaneous MWA group (16.2% vs 73.0%, P < .001). Conclusion There were no significant differences regarding oncologic outcomes and complications between percutaneous microwave ablation and laparoscopic partial nephrectomy for patients with cT1a renal cell carcinoma. Percutaneous microwave ablation led to smaller renal function change and lower blood loss. For patients who cannot be subjected to the risks of more invasive laparoscopic partial nephrectomy, percutaneous microwave ablation could be an alternative less invasive treatment option. © RSNA, 2020 Online supplemental material is available for this article.

Image-Guided Percutaneous ‎Microwave Ablation Versus Cryoablation For Hepatocellular Carcinoma In High-Risk Locations: Intermediate-Term Results

Objective

The aims of this study were to compare the clinical outcomes between image-guided percutaneous microwave ablation (MWA) and cryoablation (CRA) in patients with hepatocellular carcinoma (HCC) in high-risk locations and to identify the prognostic factors associated with the two treatment methods.

Methods

This retrospective study was institutional review board approved. A total of 120 patients (88 men and 32 women) with one hundred and thirty-four HCC lesions in high-risk locations from April 2014 to March 2018 were reviewed. Sixty-four patients underwent MWA and 56 patients underwent CRA. Survival, recurrence and complications were compared between the two groups. Effect of changes in key outcomes (i.e., overall survival (OS), recurrence-free survival (RFS) and local tumor progression (LTP)) was statistically analyzed with the log rank test. Univariate and multivariate analysis were performed on clinicopathological variables to identify factors affecting intermediate-term outcomes.

Results

The OS and RFS after MWA were comparable to those of CRA (P =0.141, and P=0.469, respectively). The LTP and major complication in MWA group was higher than those in CRA group (P=0.003, and P=0.039). Univariate analysis showed that age (P=0.007), tumor size (P=0.001), and Child-Turcotte-Pugh (CTP) grade (P=0.003) were risk factors for OS, and multivariate analysis results showed that older age (≥65 years) (P=0.002, HR:3.338, 95% CI:1.928–5.281), 3.0–5.0 cm in size (P<0.001, HR: 3.312, 95% CI: 1.872–4.489) and CTP grade B (P=0.001, HR:3.382, 95% CI: 1.882–5.902) were independently associated with poor OS.

Conclusion

CRA had comparable oncologic outcomes with MWA and could be a safe and effective treatment for HCC in high-risk locations.

A novel nomogram to predict the local tumor progression after microwave ablation in patients with early-stage hepatocellular carcinoma: A tool in prediction of successful ablation

OBJECTIVES

To develop a nomogram for the local tumor progression (LTP) in patients with early-stage hepatocellular carcinoma (HCC) after computed tomography-guided percutaneous microwave ablation (CT-PMWA) and to assess clinical-pathologic risk factors for individual LTP estimation. Furthermore, we compared the prognostic predictive ability for LTP between the nomogram and the traditional staging systems.

METHODS

This retrospective study was approved by the institutional review board. Five hundred and forty treatment-naïve patients with HCC according to the Milan criteria, who subsequently underwent CT-PMWA were reviewed from 2009 to 2019. Baseline characteristics were collected to identify the risk factors for the determination of LTP after CT-PMWA. The multivariate Cox proportional-hazards model based on significant prognostic factors of LTP was used to construct the nomogram, which was then assessed for its predictive accuracy using mainly the Harrell's C-index and time-dependent area under the curve (tAUC).

RESULTS

After a median follow-up time of 28.7 months, 6.5% (35/540) patients had LTP. The nomogram was developed based on the tumor size, tumor number, Child-Turcotte-Pugh (CTP) grade, platelet, and alanine aminotransferase (ALT). The nomogram had good calibration and discriminatory abilities in the training set, with C-indexes of 0.799 (95% confidence interval (CI): 0.738, 0.860), and tAUCs of 0.844 (CI: 0.728, 0.895), that were greater than those of traditional staging systems. Internal validation with 1000 bootstrap resamples had a good C-index of 0.735 (CI: 0.648, 0.816).

CONCLUSIONS

The nomogram model can be used to predict accurately LTP after CT-PMWA for early-stage HCC, as well as to assist physicians during the therapeutic decision-making process.

Local treatment of oligometastatic disease: current role

The presence of distant metastases has long been a predictor of poor outcome in solid cancer. However, in an oncologic situation called oligometastatic disease (OMD), multiple studies have revealed a survival benefit with aggressive treatment of these metastases. Besides surgery and radiation therapy, local thermal therapies have developed into a treatment option for OMD. Most studies concerning local therapy of OMD are available for colorectal cancer, which is therefore the focus of this article. Furthermore, this review gives a basic overview of the most popular ablation techniques for treatment of OMD.

Efficacy and safety of cooled and uncooled microwave ablation for the treatment of benign thyroid nodules: a systematic review and meta-analysis

PURPOSE

To evaluate the effectiveness and safety of microwave ablation (MWA), including cooled MWA (cMWA) and uncooled MWA (uMWA), for the treatment of benign thyroid nodules (BTNs).

METHODS

The databases of MEDLINE, EMBASE and Cochrane library were searched up to 3 Jun, 2018. In this meta-analysis, data of volume reduction rates (VRRs) at the 3-, 6- and 12-month follow-up, and complications are obtained to evaluate the effectiveness and safety of cMWA and uMWA for the treatment of BTNs.

RESULTS

Nine studies involving 1461 patients with 1845 BTNs were included. The pooled VRR at the 3-month follow-up after MWA therapy reached 54.3% (95% CI: 45.3-63.3%, I2 = 97.6%), 73.5% (95% CI: 66.7-80.3%, I2 = 94.9%) at the 6-month follow-up, and 88.6% (95% CI: 84.9-92.4%, I2 = 92.7%) at the 12-month follow-up. The pooled proportions of overall, major and minor complications were 52.4% (95% CI: 29.8-74.9%; I2 = 99.5%), 4.8% (95% CI: 2.7-7.0%; I2 = 55.9%) and 48.3% (95% CI: 31.2-65.4%; I2 = 99.7%). Both cMWA and uMWA achieved similar pooled VRR at the 3-month follow-up (58.4 vs 45.3%, P = 0.07) and pooled proportion of major complications (4.9 vs 5.0%, P = 0.49), while uMWA had higher pooled proportions of overall and minor complications than cMWA (97.8 vs 29.7%, P < 0.01; 97.8 vs 21.0%, P < 0.01), with more patients suffering pain and skin burn after uMWA (100 vs 5.5%, P < 0.01; 47.2 vs 0.2%, P < 0.01).

CONCLUSION

MWA is an effective treatment modality for BTNs. When considering the patient's comfort, cMWA would be a more preferable procedure with less complications.

Ultrasound-guided percutaneous microwave ablation vs. surgical resection for thoracoabdominal wall implants from hepatocellular carcinoma: intermediate-term results

OBJECTIVE

The aims of this study were to compare the clinical outcomes between ultrasound (US)-guided percutaneous microwave ablation (MWA) and surgical resection (SR) in patients with thoracoabdominal wall implants from hepatocellular carcinom (HCC) and to identify the prognostic factors associated with the two treatment methods.

MATERIALS AND METHODS

A total of 47 patients (mean age, 56.7 ± 15.9 years, range, 18-78 years; 34 men and 13 women) with 61 thoracoabdominal wall HCC seeding were included from April 2007 to May 2017. Twenty-five patients underwent US-guided MWA and 22 patients underwent SR. Survival, recurrence and liver function were compared between the two groups. Effect of changes in key parameters (i.e. overall survival (OS), disease-free survival (DFS) and local tumour reoccurrence-free (LTRF)) was statistically analysed with the log-rank test. Univariate and multivariate analyses were performed on several clinicopathological variables to identify factors affecting long-term outcome and recurrence.

RESULTS

The OS, DFS and LTRF after MWA were comparable to those of SR (p =0.493, p = 0.578 and p =0.270, respectively). Estimated 5-year overall survival rates were 63% after MWA and 48.1% after SR; for disease-free survival, estimated 5-year rates were 67.5% after MWA and 48.8% after SR; estimated 24-month LTRF rates were 71.3% after MWA and 87.8% after SR. The MWA group had less surgical time (p = <0.001), estimated blood loss (p = <0.001) and post-operative hospitalisation (p = 0.032) and cost (p = 0.015). Multivariate analysis showed remnant intrahepatic tumour (p =0.007), Child Pugh grade (p = 0.009) and metastasis (p= <0.001), were predictors for survival rate.

CONCLUSIONS

Ultrasound-guided percutaneous MWA is a safe and effective treatment method for metastatic HCC on the thoracoabdominal wall with similar outcomes to SR. Residual intrahepatic HCC, Child Pugh grade and distant metastasis are predictors for survival.