Research advances in thermal ablation for lung cancer / 中国胸心血管外科临床杂志

@#Although surgical resection remains to be the best treatment strategy for stageⅠnon-small cell lung cancer (NSCLC), percutaneous thermal ablation offers an important option for patients who are unable to undergo surgical resection. Currently, there are three main thermal ablation methods used in the treatment of lung cancer, including radiofrequency ablation (RFA), microwave ablation (MWA) and argon-helium cryoablation (AHC). With the improvement of technique and the accumulation of experience in the treatment of lung cancer, some limitations are disclosed in the initial application of RFA, such as heat sink effect, skin burns and rapid carbonization. These shortcomings have been overcome in the development of MWA and AHC. The feasibility and safety of thermal ablation for the treatment of lung cancer has been demonstrated and its efficacy has been significantly improved (especially for the tumour diameter≤3 cm). This article will focus on the application and recent research developments of these ablation techniques in the treatment of lung cancer.

"Leverage pry-off method" for effective prevention of thermal injury during microwave ablation of benign thyroid nodules / 南方医科大学学报

OBJECTIVE@#To assess the safety and efficacy of"leverage pry-off method"for preventing thermal injury during microwave ablation of benign thyroid nodules.@*METHODS@#From July, 2017 to September, 2019, a total of 348 patients with benign thyroid nodules underwent ultrasound-guided microwave ablation. For protecting from thermal injury during the ablation, "hydrodissection technique" was used in 174 of the patients (admitted from July, 2017 to August, 2018) and "leverage pry-off method" in the other 174 patients (admitted from September, 2018 to September, 2019). All the patients were followed up for 1 to 12 months after the operation for observation of severe complications and nodular residues.@*RESULTS@#Ultrasound-guided microwave ablation was completed in all the 348 patients. The most common severe complication associated with the ablation was voice change, occurring in 3 cases (1.7%) in "hydrodissection technique" group and in 4 (2.3%) in the "leverage pry-off method" group, showing no significant difference between the two groups (P>0.05). During the follow-up, no significant difference was found in the rate of nodular residues between the "hydrodissection technique" group and "hydrodissection technique" group (9.8% vs 10.9% (P>0.05).@*CONCLUSIONS@#The "leverage pry-off method" is simple and effective for preventing thermal injury during microwave ablation of benign thyroid nodules.

Mechanism of the therapeutic effect of Tetrandrine on striatum injury caused by microwave radiation / 中华放射医学与防护杂志

Objective:To study the therapeutic effect Tetrandrine (TET) on striatal injury caused by microwave radiation and underlying mechanism.Methods:C57BL/6N mice were randomly divided into blank control group (C), radiation control group (R), TET group (TET) and TET combined with radiation group (TET+ R). The mice of radiation group were exposed to 2.856 GHz 8 mW/cm2 microwave on whole-body for 15 min. TET (60 mg/kg) was injected intraperitoneally once a day for 3 consecutive days. The TET structure was verified by ultraviolet spectrophotometry. The open field experiment was used to detect the change of anxiety in mice. Histopathological and ultrastructural changes of the striatum were observed by light microscopy and transmission electron microscopy (TMT). Quantitative real-time PCR (qPCR) was used to detect gene expression changes of voltage-gated calcium channel (VGCC) subtype in the striatum.Results:The open field experiments showed that the time and distance of mice to explore the central region after microwave radiation were significantly lower than that before radiation ( t=4.60, 5.18, P<0.01), and the TET administration significantly improved these changes ( F=1.43, 4.37, P < 0.05). 7 d after microwave radiation, some neuronal nuclei in the striatum of mice contracted and could be stained deeply, which was more obvious in the globus pallidus area. The partial neuronal apoptosis, swelling and cavitation of glial cell mitochondria, blurring of synaptic gaps, and widening of perivascular gaps in the striatum were observed by TMT. The above lesions were significantly rescued after TET administration. But both microwave radiation and TET administration had no significant effect on the gene expressions of striatal VGCC ( P > 0.05). Conclusions:TET has a therapeutic effect on anxiety-like behavior and structural damage of striatum caused by microwave radiation, which is independent of the expression of striatal VGCC genes.

Efficacy of microwave ablation versus radiofrequency ablation in the treatment of colon cancer liver metastases: a meta-analysis / 中华肝胆外科杂志

Objective:To explore the best treatment for local ablation of colon cancer liver metastases (CRLM) by meta-analysis.Methods:The electronic databases of PubMed, Web of Science, Embase, CNKI and the Cochrane Library were searched from the establishment to August 22, 2022, and studies that report outcomes with comparison between microwave ablation (WMA) and radiofrequency ablation (RFA) in CRLM treatment were selected by inclusion and exclusion criteria. Furthermore, the perioperative and survival data were statistically summarized and analyzed by Review Manager 5.3 software.Results:A total of 5 retrospective studies were included with a total sample size of 648 cases, including 316 cases (48.8%) in the WMA group and 332 cases (51.2%) in the RFA group. The results of meta-analysis showed that locoregional recurrence rate in WMA group was significantly lower than that in RFA group. The 1-year and 2-year disease-free survival (DFS) of the WMA group was significantly better than that of the RFA group with HR of 1.77 ( P=0.04, 95% CI: 1.04-3.02) and 1.60 ( P=0.02, 95% CI: 1.09-2.35), respectively. Conclusion:The local control rate and 1-year and 2-year DFS of WMA were superior to RFA.

“Liquid seal to detoxification – drying and puffing” of two stage processing technology design and pharmacodynamic study of aconite (Aconiti Lateralis Radix Praeparata) processed by microwave / 药学学报

Establish a production line with controllable process and high intelligence, contribute to improve the quality and production efficiency of aconite processed by microwave, and promote the transformation and application of aconite processed by microwave. According to the principle of aconite detoxification and the characteristics of industrial microwave equipment, an industrial production line of aconite processed by microwave was established with diester alkaloids and monoester alkaloids as indicators, and pilot production was carried out. At the same time, the content of active constituents and efficacy were compared with that of the main processed products, such as Shengfupian, Baifupian and Heishunpian. The results showed that the industrial production of aconite processed by microwave can be divided into two stages: "Liquid seal to detoxification - drying and puffing". The content of monoester alkaloids in 10 batches of aconite processed by microwave was 0.071%-0.166% and the content of diester alkaloids was 0.004%-0.016%, which met the relevant requirements of the Chinese Pharmacopoeia in 2020. Compared with Heishunpian and Baifupian, the retention rate of the effective components of aconite processed by microwave was higher. Pharmacological experiments showed that aconite processed by microwave not only retained the anti-inflammatory and analgesic activities of Heishunpian and Baifupian, but also significantly increased the levels of leukocytes and lymphocytes in mice with liver cancer chemotherapy, enhanced the CD4/CD8 ratio in spleen cells of mice (P < 0.05), thus regulating the body's immunity. However, this effect of Baifupian was weak, while Heishunpian and Shengfupian had no such effect. Through the above research, this study established microwave processing line with controllable process and high intelligence, as well produced the aconite processed by microwave with low toxicity and stable quality. It laid a foundation for the industrialized continuous production and clinical positioning of aconite by microwave processed, and provided scientific support for the development and application of microwave technology in the field of traditional Chinese medicine. All animal experiments in this study were reviewed and approved by the Experimental Animal Ethics Committee of Chengdu University of Traditional Chinese Medicine before being carried out (Approval No. 2020-28).

Application of DynaCT combined with 3D iGuide puncture technique to microwave ablation of lung cancer / 中国胸心血管外科临床杂志

@#Objective    To investigate the feasibility and safety of DynaCT microwave ablation (MWA) guided by 3D iGuide puncture technology for lung cancer. Methods    The clinical data of 19 patients with primary or metastatic lung cancer who underwent DynaCT MWA from June 2019 to December 2020 in our hospital were retrospectively analyzed, including 15 males and 4 females with an average age of 64.9±11.7 years. The technical success rates, adverse reactions and complications, postoperative hospital stay, and local therapeutic efficacy were recorded. Results    Technical success rate was 100.0%. The mean time required to target and place the needle was 15.7±3.7 min and the mean ablation time was 5.7±1.6 min. Thirteen patients underwent biopsy synchronously before the ablation, and 10 (76.9%) patients had positive pathological results. The main adverse reactions were pain (7/19, 36.8%), post-ablation syndrome (4/19, 21.1%) and cough (2/19, 10.5%). The minor complications were pneumothorax (6/19, 31.6%), hemorrhage (5/19, 26.3%), pleural effusion (2/19, 10.5%) and cavity (1/19, 5.3%). Three patients had moderate pneumothorax and received closed thoracic drainage. The median hospitalization time after ablation was 2.0 (2.0, 3.0) d, and no patient died during the perioperative period. The initial complete ablation rate was 89.5% (17 patients) and the incomplete ablation rate was 10.5% (2 patients) at 1-month follow-up, and no local progression was observed. Conclusion    DynaCT MWA of lung cancer under the guidance of 3D iGuide system is safe and feasible with a high short-term local control rate, but the long-term efficacy remains to be further observed.

Effects of microwave radiation on learning and memory and neurotransmitters in the hippocampus / 中国辐射卫生

@#The central nervous system is one of the most sensitive targets of microwave radiation. Microwave radiation can affect spatial learning and memory and neural information transmission. The effects of microwave radiation on neurotransmitters in the hippocampus and the underlying mechanisms are still unclear. This paper reviews the effects of microwave radiation on learning/memory and neurotransmitters as well as the mechanisms of action on neurotransmitters. This paper aims to provide a scientific basis for future research in this area.

Anti-PD-L1 antibody enhances curative effect of cryoablation via antibody-dependent cell-mediated cytotoxicity mediating PD-L1highCD11b+ cells elimination in hepatocellular carcinoma

Cryoablation (CRA) and microwave ablation (MWA) are two main local treatments for hepatocellular carcinoma (HCC). However, which one is more curative and suitable for combining with immunotherapy is still controversial. Herein, CRA induced higher tumoral PD-L1 expression and more T cells infiltration, but less PD-L1highCD11b+ myeloid cells infiltration than MWA in HCC. Furthermore, CRA had better curative effect than MWA for anti-PD-L1 combination therapy in mouse models. Mechanistically, anti-PD-L1 antibody facilitated infiltration of CD8+ T cells by enhancing the secretion of CXCL9 from cDC1 cells after CRA therapy. On the other hand, anti-PD-L1 antibody promoted the infiltration of NK cells to eliminate PD-L1highCD11b+ myeloid cells by antibody-dependent cell-mediated cytotoxicity (ADCC) effect after CRA therapy. Both aspects relieved the immunosuppressive microenvironment after CRA therapy. Notably, the wild-type PD-L1 Avelumab (Bavencio), compared to the mutant PD-L1 atezolizumab (Tecentriq), was better at inducing the ADCC effect to target PD-L1highCD11b+ myeloid cells. Collectively, our study uncovered the novel insights that CRA showed superior curative effect than MWA in combining with anti-PD-L1 antibody by strengthening CTL/NK cell immune responses, which provided a strong rationale for combining CRA and PD-L1 blockade in the clinical treatment for HCC.

One case report of recurrent primary hyperparathyroidism caused by iatrogenic implant ectopic parathyroid adenoma / 中华内分泌外科杂志

Parathyroid adenoma (PTA) is an important cause of hyperparathyroidism (HPT) . The author reported a case of HPT caused by proliferation of parathyroid cells caused by implantation during surgery, and the formation of adenoma in sternocleidomastoid muscle was detected. The understanding of primary hyperparathyroidism (PHPT) caused by ectopic PTA was analyzed from clinical symptoms, laboratory examination, the neck Doppler ultrasound, imaging ( 99TC m-MIBI SPECT/CT fusion imaging, CT) and pathological examination results, combined with the parathyroidism of the patient during the first operation.

Research progress in antenna technology for microwave imaging of stroke / 国际生物医学工程杂志

The diagnostic technology of acute stroke by microwave imaging has the advantages of being non-ionizing, fast, small, and low-cost. Therefore, this technology is expected to become an auxiliary or alternative means to CT and MRI technology. As the signal transmitting and receiving device of the microwave imaging system, the antenna has an important influence on the performance of the imaging system. At present, there are many antennas with different performances used in imaging systems, but there is a lack of clear evaluation criteria for them. In this paper, several typical antennas were introduced, their advantages and disadvantages from the perspective of bandwidth and near-field were analyzed, and the common requirements of imaging systems for antennas and the performance indicators of various types of imaging systems were summarized. Moreover, the development trend of antenna technology for microwave imaging was pointed out to provide a reference for the study of stroke microwave imaging technology.

Ultrasound-guided anhydrous ethanol and microwave ablation for functional parathyroid cyst: a case report / 南方医科大学学报

We report a case of functional parathyroid cyst treated by ultrasound-guided anhydrous ethanol sclerotherapy and microwave ablation. The 63-year-old female patient was diagnosed to have functional parathyroid cyst with hypercalcemia, high PTH and cystic space-occupying lesions in the neck by ultrasound, radionuclide scanning and PTH measurement of the cystic fluid. The patient refused to receive cyst resection, and anhydrous ethanol sclerotherapy with microwave ablation was performed under ultrasound guidance. The procedure was completed smoothly without any complications either during or after the operation. Follow-up examination of the patient at 18 months after the operation showed a significant reduction of the mass and normal blood calcium and iPTH levels, demonstrating a clinical cure of the patient. Ablative treatment of functional parathyroid cyst has not been documented so far. This approach provides a minimally invasive treatment modality for such cases where surgical resection is not an option, but its efficacy and safety need to be evaluated in more cases with longer follow-up time.

Expression of PD-L1 in Primary Colorectal Cancer and Its Predictive Value for Recurrence After Microwave Ablation of Liver Metastases / 肿瘤防治研究

Objective To investigate the expression of programmed death ligand 1(PD-L1) in primary tumor cells(TCs) and tumor-infiltrating immune cells(TICs) in patients with liver metastases from colorectal cancer(CRC) and determine its predictive value for recurrence after microwave ablation(MWA) of liver metastases. Methods The paraffin-embedded specimens of 28 patients with CRC liver metastasis were collected retrospectively. The expression of PD-L1 in the primary lesions was detected by immunohistochemistry, and the relationship between PD-L1 and clinical features was analyzed. Recurrence-free survival(RFS) was analyzed by Kaplan-Meier method and Log rank test. Cox proportional hazards regression model was used to analyze the factors influencing recurrence. Results The positive rates of PD-L1 in TCs and TICs in primary CRC were 14.3%(4/28) and 46.4%(13/28), respectively. PD-L1 expression in primary TICs of CRC patients with liver metastases was significantly correlated with the largest hepatic tumor diameter (P < 0.05). PD-L1 expression in primary TICs of CRC patients with liver metastasis was correlated with poor RFS after MWA (P < 0.05). PD-L1 expression in primary TICs and the largest hepatic tumor diameter > 3 cm in CRC patients with liver metastases were the risk factors for recurrence after MWA (P < 0.05). Conclusion PD-L1 expression in primary TICs of CRC patients with liver metastasis may increase the risk of recurrence after MWA for liver metastasis.

Microwave sensor for recognition of abnormal nodule tissue on body surface / 生物医学工程学杂志

For the detection and identification of abnormal nodular tissues on the body surface, a microwave sensor structure loaded with a spiral resonator is proposed in this paper, a sensor simulation model is established using HFSS software, the structural parameters are optimized, and the actual sensor is fabricated. The S21 parameters of the tissue were obtained when nodules appeared by simulation, and the characteristic relationship between the difference of S21 parameters with position was analyzed and tested experimentally. The results showed that when nodules were present in normal tissues, the curve of S21 parameter difference with position change had obvious inverted bimodal characteristics, and the extreme value of S21 parameter difference appeared when the sensor was directly above the nodules, which was easy to identify the position of nodules. It provides an objective detection tool for the identification of abnormal nodular tissues on the body surface.

A Comparative Study on Microwave Tissue Processing and Conventional Tissue Processing

Introduction: The field of medical technology is ever evolving which necessitates traditional techniques replaced by newer technologies. Contrary to this histotechniques in histopathology has remained static with hardly any changes where tissue preparation for microscopic examination still remains time consuming. However recent emergence of automatic tissue processor and microwaves has successfully reduced the time from several days to 1-2 days. Materials and Methods: 133 different tissue blocks from the department of Oral and Maxillofacial Pathology were used in the current study. Each tissue received was fixed in 10% formalin overnight, sectioned into approximately two halves. One tissue was sent for routine processing whereas the other was sent for microwave processing. After processing the sections were embedded, section and stained with H and E. A pathologist evaluated the stained slides and the results so obtained were analyzed statistically. Results: Microwave processing considerably cut down the processing time from days to merely hours. Microwave stained slides showed no loss of cellular and nuclear details, uniform-staining characteristics and was of excellent quality. Conclusion: The cellular details, nuclear details and staining characteristics of microwave stained sections were better than or equal to the routine stained sections. The overall quality of microwave-stained sections was found to be better than the routine stained sections in majority of cases

Comparison of Application of MD-VF-Auto SEM Method and Plankton Gene Multiplex PCR System in the Diagnosis of Drowning / 法医学杂志

OBJECTIVES@#To compare the application effect of microwave digestion - vacuum filtration - automated scanning electron microscopy (MD-VF-Auto SEM) method and plankton gene multiplex PCR system in the diagnosis of drowning.@*METHODS@#Lung, liver and kidney tissue of 10 non-drowning cases and 50 drowning cases were prepared for further MD-VF-Auto SEM method analysis and plankton gene multiplex PCR system analysis. The positive detection rate of the two methods in each tissue was calculated.@*RESULTS@#The positive rate of the MD-VF-Auto SEM method detecting diatoms in drowning cases was 100%, and few diatoms were detected in the liver and kidney tissues of 6 non-drowning cases. By using the plankton gene multiplex PCR system, the diatom positive rate of drowning cases was 84%, and all the non-drowning cases were negative. There were significant differences in the positive rate of the liver, kidney tissues between MD-VF-Auto SEM method and plankton gene multiplex PCR system (P<0.05), as well as the total positive rate of cases. However, no significant differences were found in the positive rates of lung tissues (P>0.05).@*CONCLUSIONS@#MD-VF-Auto SEM method is more sensitive than plankton gene multiplex PCR system in diatom test. But the plankton gene multiplex PCR system can also detect plankton other than diatoms. Combination of the two methods can provide a more reliable basis for the diagnosis of drowning.

Application of Diatoms Quantitative Analysis in the Diagnosis of Drowning / 法医学杂志

OBJECTIVES@#To retrospectively analyze diatom test cases of corpses in water and discuss the value of quantitative analysis of diatoms in the diagnosis of drowning.@*METHODS@#A total of 490 cases of water-related death were collected. They were divided into drowning group and postmortem immersion group according to the cause of death. Diatoms in lung, liver, kidney tissue and water sample were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy (MD-VF-Auto SEM) method. The ratios of content of diatoms in lung tissue and water sample (CL/CD) were calculated.@*RESULTS@#The results of diatom test for three organs (lung, liver and kidney) were all positive in 400 cases (85.5%); the content of diatom in lung, liver, kidney tissues, and water samples of drowning group were (113 235.9±317 868.1), (26.7±75.6), (23.3±52.2) and (12 113.3±21 760.0) cells/10 g, respectively; the species of diatom were (7.5±2.8), (2.6±1.9), (2.9±2.1) and (8.9±3.0) types, respectively; the CL/CD of drowning group and postmortem immersion group were (100.6±830.7) and (0.3±0.4), respectively.@*CONCLUSIONS@#Quantitative analysis of diatoms can provide supportive evidence for the diagnosis of drowning, and the parameter CL/CD can be introduced into the analysis to make a more accurate diagnosis of drowning.

Determination of six heavy metals in peanuts using microwave-assisted digestion-inductively coupled plasma mass spectrometry with an octopole reaction system / 预防医学

Objective @#To establish a microwave-assisted digestion-inductively coupled plasma mass spectrometry (ICP-MS) with an octopole reaction system for simultaneous determination of six heavy metals in peanuts, including Cr, Ni, As, Cd, Pb, Hg. @*Methods @#Peanut samples were shelled and crushed evenly, and 0.350 0 g was accurately weighed and digested with 5 mL nitric acid and 1 mL hydrogen peroxide in a digestion tank. Following microwave-assisted digestion, pure water was used to quantify the samples, and internal standards and an octopole reaction system were used to remove the interference. Then, the contents of six heavy metals were determined in peanuts by ICP-MS. The accuracy and precision of ICP-MS were evaluated using national criteria ( GBW 10013 and GBW 10044 ) and spike-and-recovery testing. @*Results @#The six heavy metals showed good linearity at the selected linear range ( r≥0.999 8 ). The detection limits of ICP-MS ranged from 0.001 4 to 0.023 8 ng/mL, and the spike-and-recovery rates ranged from 94.7% to 98.8%, with the relative standard deviations ranging from 0.7% to 3.6%. In addition, the determination results of the standard reference materials were all within the normal reference range. The detection of six heavy metals was 100.0% in 60 peanut samples, and the contents of six heavy metals were all low.@*Conclusion @#The established ICP-MS assay is feasible for simultaneous determination of multiple heavy metals in peanuts.

Determination of 17 elements in placenta by microwave digestion-inductively coupled plasma mass spectrometry / 预防医学

Objective@#To establish a microwave digestion-inductively coupled plasma mass spectrometry assay for simultaneous determination of multiple elements in placenta.@*Methods@#Fresh placental tissues were dried at 60 ℃ for 15 h and ground into power. Then, 0.3 g homogenized samples were digested in a microwave digestion system. The interference from mass spectrometry was removed using the kinetic energy discrimination model in the inductively coupled plasma mass spectrometry, and the baseline interference was removed by online internal standards. The contents of 17 elements were determined in placental specimens using the established microwave digestion -inductively coupled plasma mass spectrometry assay, including V, Ni, Co, Fe, Cr, Cu, Zn, Mn, As, Sn, Sb, Ba, Se, Cd, Pb, Hg and Tl.@*Results@#Good linearity was shown for V, Ni, Co, Cr, As, Se, Cd, Pb and Tl at 1 to 50 µg/L, Fe at 100 to 5 000 µg/L, Zn, Cu, Mn and Ba at 10 to 500 µg/L, Sn and Sb at 0.1 to 5 µg/L, and Hg at 0.2 to 2 µg/L, with all correlation coefficients of 0.999 8 and higher. The detection limits of these 17 elements ranged from 0.5 to 100 μg/kg, with relative standard deviations of 2.1% to 6.5%, and recovery rates of 83.3% to 110.0%. The determination results of 17 elements were all within the normal reference range defined in the certified reference materials of chicken (GBW10018). @*Conclusions@#The microwave digestion-inductively coupled plasma mass spectrometry established based on optimized pretreatments and mass spectrometry detection conditions, is feasible for simultaneous determination of multiple elements in placenta.

Risk factors of residual tumor in single small hepatocellular carcinoma after thermal ablation treatment / 中华内科杂志

Objective:To evaluate the risk factors of residual tumor after thermal ablation in patients with small hepatocellular carcinoma.Methods:This was a retrospective study recruiting 107 patients diagnosed as single hepatocellular carcinoma with maximum diameter ≤3 cm from December 2009 to August 2015 in National Cancer Center. The cohort enrolled 81 males and 26 females, including 83 patients younger than 70 years old. All patients were treated with radiofrequency ablation or microwave ablation, and evaluated by CT or MRI after 4-6 weeks compared with baseline data. Potentially related factors were analyzed such as patients′ characteristics, tumor location and adjacent, ablation pattern, hepatitis B/C infection. A multivariate logistic regression analysis was conducted for the independence of risk factors.Results:Six patients (5.6%) with residual tumor was detected in the whole population of 101 cases. Univariate analysis suggested that tumor adjacent to vascular structure, poor differentiation, AFP≥200 μg/L were the risk factors of residue disease (all P<0.05). Multivariate logistic regression suggested that pathological type of poorly differentiated tumor was the only independent risk factor ( HR=2.26,95% CI 0.25-20.50, P=0.030). Conclusions:Poorly differentiated pathology is an independent predictive factor for residual disease in small hepatocellular carcinoma after thermal ablation. Such patients should be routinely followed up after operation.

Microwave ablation of early-stage hepatocellular carcinoma affects survival prognostic factors / 中华超声影像学杂志

Objective:To identify the risk factors for survival prognosis of patients with early-stage hepatocellular carcinoma (HCC) after ultrasound-guided percutaneous microwave ablation (US-PMMA), and to compare the overall survival (OS), cancer specific survival (CSS) and disease-free survival (DFS) between different early-stage HCC patients.Methods:A total of 1 563 patients with early-stage hepatocellular carcinoma (HCC) who underwent MWA in the interventional ultrasound department of the Chiese PLA General Hospital from January 2002 to December 2017 were retrospectively analyzed. Propensity score matching (PSM) balanced the baseline parameters between the elderly group (≥60 years) and the young group (<60 years). Multivariate Cox regression analysis was used to identify the risk factors of OS, CSS and DFS. OS, CSS and DFS probabilities for different patients stratified by respective predictors were calculated with Kaplan-Meier method and compared using the Log-Rank test.Results:All parameters were balanced except for age after PSM.Tumor diameter(95% CI=1.1-1.4, P<0.001), number of tumors(95% CI=1.2-1.9, P<0.001), γ-GT (95% CI=1.0-1.0, P<0.001) and AFP (HR=1.5, 95% CI=1.2-1.8, P<0.001) were shared predictors for OS, CSS and DFS. Age (95% CI=1.2-1.8, P<0.001) and neutrophile to lymphocyte ratio (NLR) (95% CI=1.0-1.0, P=0.043) were another two predictors for both OS and CSS. Albumin predicted OS only, and sex and cirrhosis just predicted DFS. Over the follow-up period (12-156 months), log-rank tests showed that all predictors significantly affected the corresponding OS, CSS or DFS(all P<0.01). Among them, multiple tumors had the greatest impact on OS, CSS and DFS. Compared with patients with single lesion, OS, CSS and DFS in patients with multiple lesions decreased by 9.2%, 2.5% and 4.1% respectively at the 12 years of follow-up, and the median survival time was shortened by 12.3 months, 25.0 months and 11.3 months, respectively (log-rank P=0.049 for OS; P=0.007 for CSS; P<0.001 for DFS). Conclusions:The prognostic benefits from MWA treating early-stage HCC in patients with different survival risk factors are different. Clinically feasible correction of hypoproteinemia and liver disfunction are of great significance to improve the prognosis of early-stage HCC patients after US-PMMA.