Experimental study on monitoring microwave ablation efficacy by real-time shear wave elastography in ex vivo porcine brain.

Objective: Glioma constitutes the most common primary malignant tumor in the central nervous system. In recent years, microwave ablation (MWA) was expected to be applied in the minimally invasive treatment of brain tumors. This study aims to evaluate the feasibility and accuracy of microwave ablation in ex vivo brain tissue by Shear Wave Elastography (SWE) to explore the application value of real-time SWE in monitoring the process of MWA of brain tissue.Methods: Thirty ex vivo brain tissues were treated with different microwave power and ablation duration. The morphologic and microscopic changes of MWA tissues were observed, and the diameter of the ablation areas was measured. In this experiment, SWE is used to quantitatively evaluate brain tissue's degree of thermal injury immediately after ablation.Results: This study It is found that the ablation range measured by SWE after ablation is in good consistency with the pathological range [ICCSWEL1-L1 = 0.975(95% CI:0.959 - 0.985), ICCSWEL2-L2 = 0.887(95% CI:0.779 - 0.938)]. At the same time, the SWE value after ablation is significantly higher than before (mean ± SD,9.88 ± 2.64 kPa vs.23.6 ± 13.75 kPa; p < 0.001). In this study, the SWE value of tissues in different pathological states was further analyzed by the ROC curve (AUC = 0.86), and the threshold for distinguishing normal tissue from tissue after ablation was 13.7 kPa. The accuracy of evaluating ablation tissue using SWE can reach 84.72%, providing data support for real-time quantitative observation of the ablation range.Conclusion: In conclusion the accurate visualization and real-time evaluation of the organizational change range of the MWA process can be realized by real-time SWE.

Percutaneous thermal segmentectomy for liver malignancies over 3 cm: mid-term oncological performance and predictors of sustained complete response from a multicentric Italian retrospective study.

INTRODUCTION: Percutaneous thermal segmentectomy is a single-step combination of microwave ablation, performed during arterial occlusion obtained with a balloon micro catheter, followed in the same session by balloon-occluded TACE. The aim of this multicenter retrospective study is to report the mid-term oncological performance of this technique for liver malignancies > 3.0 cm and to identify risk factors for the loss of sustained complete response. METHODS: Oncological results were evaluated with CT or MRI according to m-RECIST (HCC) and RECISTv1.1 (metastasis/intra-hepatic cholangiocarcinoma, iCC) at 1-month, 3-6-month and then at regular-6-month intervals. To identify predictive variables associated with not achieving or losing complete response two mixed-effects multivariable logistic regression models were constructed. RESULTS: Sixty-three patients (40/23, male/female) with primary liver malignancies (HCC = 49; iCC = 4) and metastasis (n = 10) were treated. Median diameter of target lesion was 4.5 cm (range 3.0-7.0 cm). The median follow-up time was 9.2 months. At one-month follow-up, 79.4% of patients presented with a complete response and the remaining 20.6% were partial responders. At the 3-6-month follow-up, reached by 59 of the initial 63 patients, 83.3% showed a sustained complete response, while 10.2% had a partial response and 8.5% a local recurrence. At the last follow-up, 69.8% of the lesions showed a complete response. The initial diameter of the target lesion ≥ 5.0 cm was the only independent variable associated with the risk of failure in maintaining a complete response at 6 months (OR = 8.58, 95% CI 1.38-53.43; P = 0.02). CONCLUSION: Percutaneous thermal segmentectomy achieves promising oncological results in patients with tumors > 3.0 cm, with tumor dimension ≥ 5.0 cm being the only risk factor associated with the failure of a sustained complete response.

Microwave Ablation, Radiofrequency Ablation, Irreversible Electroporation, and Stereotactic Ablative Body Radiotherapy for Intermediate Size (3-5 cm) Unresectable Colorectal Liver Metastases: a Systematic Review and Meta-analysis.

PURPOSE OF REVIEW: Based on good local control rates and an excellent safety profile, guidelines consider thermal ablation the gold standard to eliminate small unresectable colorectal liver metastases (CRLM). However, efficacy decreases exponentially with increasing tumour size. The preferred treatment for intermediate-size unresectable CRLM remains uncertain. This systematic review and meta-analysis compare safety and efficacy of local ablative treatments for unresectable intermediate-size CRLM (3-5 cm). RECENT FINDINGS: We systematically searched for publications reporting treatment outcomes of unresectable intermediate-size CRLM treated with thermal ablation, irreversible electroporation (IRE) or stereotactic ablative body-radiotherapy (SABR). No comparative studies or randomized trials were found. Literature to assess effectiveness was limited and there was substantial heterogeneity in outcomes and study populations. Per-patient local control ranged 22-90% for all techniques; 22-89% (8 series) for thermal ablation, 44% (1 series) for IRE, and 67-90% (1 series) for SABR depending on radiation dose. Focal ablative therapy is safe and can induce long-term disease control, even for intermediate-size CRLM. Although SABR and tumuor-bracketing techniques such as IRE are suggested to be less susceptible to size, evidence to support any claims of superiority of one technique over the other is unsubstantiated by the available evidence. Future prospective comparative studies should address local-tumour-progression-free-survival, local control rate, overall survival, adverse events, and quality-of-life.

Ablation for oligometastatic colorectal carcinoma in extrahepatic, extrapulmonary sites.

Treatment of metastatic colorectal carcinoma has evolved in the era of increasingly effective systemic therapies. Increasing survival rates provide opportunities for repeated focal therapies to be directed at limited metastatic disease. Surgical resection and other ablative therapies to eliminate oligometastases in the most common sites, namely liver and lung, have been proven to prolong survival. As such, patients develop additional sites of metastasis in the course of their disease, including adrenal, peritoneal, nodal, and skeletal metastases. Data supporting aggressive focal therapy for extrahepatic, extrapulmonary metastases are limited. This manuscript summarizes findings of surgical studies of cytoreduction in these patients, describes limited data from ablation case series that include these metastases, and presents a rationale for further investigation of thermal ablation within this patient population.

Retrospective analysis of ultrasound-guided minimally invasive treatment of various thyroid cysts.

PURPOSE: The aim of this article was to determine the efficacy and safety of the combined use of ethanol and microwave (MWA) to thyroid cysts and explore the differences of various cysts. MATERIALS AND METHODS: A total of 136 patients and 142 thyroid cystic nodules and predominantly cystic nodules received combination therapy of ethanol and MWA between January 2016 and December 2019 in BeiJing Friendship Hospital. They were divided into different groups according to the size, and the characteristics of fluid aspirated. We compared the Initial size, treatment procedure, postoperative complications, and follow-up results to analyze the characteristics of different groups. RESULTS: The combination treatments reduced the size of cysts by more than 93% with less complications at the end of follow-up. The treatment duration was longest in the colloid cysts (difference from the clear-fluid group, p < 0.01), the absolute volume of the clear-fluid group at the end of follow-up was the smallest (difference from the other two groups: P < 0.01).There were the similar mean volume reduction rate (VRR) between the large cysts and the small cysts (p > 0.05). CONCLUSION: The combination treatments were applicable to all types of cysts. Understanding the characteristics of different cystic nodules and adopting different methods are helpful for us to carry out the minimally invasive treatment of cysts better.

Feasibility of microwave ablation of the vertebral growth plate for spine growth regulation: a preliminary study.

PURPOSE: To explore the feasibility of microwave ablation (MWA) of the vertebral growth plate as a minimally invasive treatment for early-onset scoliosis. MATERIALS AND METHODS: One side of the L1-L3 vertebral growth plates were ablated using different MWA powers. Ablation safety and size were examined. Subsequently, L1-L3 vertebral growth plates were ablated on one side for 40 s at 20 W. At 2, 4, and 6 weeks after the ablation, growth changes of the spine were observed. RESULTS: No piglets died during and after ablation, and all had modified Tarlov Grade 5. The safe MWA time (time for safely ablating the vertebral growth plate) was 17.0 ± 1.5 s at 50 W, 23.0 ± 2.3 s at 40 W, 31.0 ± 3.1 s at 30 W, 47.0 ± 3.7 s at 20 W, 70.0 ± 4.2 s at 15 W, and 158.0 ± 5.0 s at 10 W. With power <15 W, the vertebral growth plate could not be effectively ablated within the safe ablation time. Within the safe ablation times, the MWA size on hematoxylin and eosin slices on a transverse diameter was between 7 and 10 mm; and that on longitudinal diameter was mainly determined by the ablation needle length. Moreover, the growth plate and annulus fibrosus on the ablated side grew poorly over time, the vertebral body showed significant wedge-shaped changes, and the spine showed significant unbalanced growth. CONCLUSION: MWA of the vertebral growth plate can be performed safely when accompanied with appropriate thermometry, and could be a new minimally invasive strategy in regulating spine growth.

A study on the efficacy of microwave ablation for benign thyroid nodules and related influencing factors.

OBJECTIVES: To explore the efficacy of microwave ablation (MWA) in the treatment of benign thyroid nodules, and analyze related influencing factors. METHODS: The clinical and ultrasound data of 115 patients with 115 benign thyroid nodules treated with MWA were retrospectively analyzed. The volume of nodules at 1, 3, 6, and 12 months after the procedure was obtained, and the volume reduction rate (VRR) at each time point was calculated. With VRR > 90% as the criterion for nodule cure, binary logistic regression was employed to screen the factors that affect the efficacy. RESULTS: ① At 1, 3, 6, and 12 months after the procedure, the volume of nodules continued to decrease, the VRR gradually increased, and the differences at each time point were statistically significant (p < 0.05). A total of 29 (25.21%) nodules disappeared completely at 12 months after the procedure; ② Multivariate stepwise logistic regression showed that there was a statistically significant difference for the internal component of nodules, enhancement mode, and immediate volume after the procedure in determining the ablation efficacy (p < 0.05); ③ The ROC curve was plotted for predicting the efficacy of MWA, with the results showing that the AUC, sensitivity, specificity, and accuracy were 0.82, 67.50, 88.00, 79.10%, respectively; ④ 11 cases (9.56%) had side effects, 10 cases (8.70%) had minor complications, and three cases (2.61%) had major complications. CONCLUSION: MWA is safe and effective in the treatment of benign thyroid nodules. The internal component of nodules, enhancement mode, and immediate volume after the procedure are independent factors that affect the efficacy of ablation.

Long-Term Effect of Microwave Ablation on Patients Undergoing Hemodialysis for Moderate Secondary Hyperparathyroidism: A Retrospective Cohort Study.

OBJECTIVES: A previous 12-month study confirmed that microwave ablation (MWA) was effective for moderate secondary hyperparathyroidism (SHPT). A further analysis was performed in this study to evaluate the efficacy of MWA for moderate SHPT over an observational follow-up period of up to 60 months. METHODS: This was a retrospective cohort study of patients involved in a previous randomized controlled trial. Patients were divided into an MWA group (those who underwent MWA followed by drug therapy according to the patient's clinical situation) and a control group (those who received drug therapy only). The primary outcome was the composite endpoint. During the efficacy assessment phase, the two groups were compared in terms of the proportion of patients with intact parathyroid hormone (iPTH) levels <300 pg/ml and the differences in iPTH levels. RESULTS: Twenty-seven patients were included in this study: 13 in the MWA group and 14 in the control group. The median (interquartile range) follow-up periods of the MWA and control groups were 58 (54-60) and 58 (49-60) months, respectively. The proportion of patients with iPTH levels <300 pg/ml in the MWA group was slightly higher than that in the control group (6/13 [46.2%] versus 2/14 [14.3%], respectively; p = .08). Furthermore, iPTH levels in the MWA group were lower than in the control group during the efficacy assessment phase (411 ± 299 pg/ml versus 516 ± 369 pg/ml, respectively; p <.01). CONCLUSIONS: MWA helped to contain the necessary iPTH levels in patients undergoing hemodialysis for moderate SHPT in a 60-month timeframe.

Study on the relationship between reduced scattering coefficient and Young's modulus of tumors in microwave ablation.

BACKGROUND AND OBJECTIVE: In the clinical treatment of tumors using microwave ablation (MWA), although temperature can be used as an important reference index for evaluating the curative effect of ablation, it cannot fully reflect the biological activity status of tumor tissue during thermal ablation. Finding multi-parameter comprehensive evaluation factors to achieve real-time evaluation of therapeutic effects has become the key for precise ablation. More and more scholars use the reduced scattering coefficient (µs') and Young's modulus (E) to evaluate the treatment outcomes of MWA. However, the intrinsic relationship between these parameters is unclear. This paper aims to investigate the specific relationship between µs' and E during MWA. MATERIAL AND METHODS: The MWA experiment was conducted on porcine liver in vitro, the two-parameter simultaneous acquisition system was designed to obtain the reduced scattering coefficient and Young's modulus of the liver tissue during MWA. The relationship between reduced scattering coefficient and Young's modulus was investigated. RESULTS: It is found that the trend of change of µs' is very similar to E in the process of MWA, i.e. first increasing and then reaching a steady state, and in some experiments there are synchronous changes. Based on this, the quantitative relationship between E-µs'  is established, enabling the quantitative estimation of Young's modulus of liver tissue based on reduced scattering coefficient. The maximum absolute error is 29.37 kPa and the minimum absolute error is 0.88 kPa. CONCLUSION: This study contributes to the further establishment of a multi-parameter MWA effectiveness evaluation model. It is also valuable for clinically evaluating the ablation outcomes of tumor in real time.

Percutaneous Ablation-Induced Immunomodulation in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths worldwide and its incidence is rising. Percutaneous locoregional therapies, such as radiofrequency ablation and microwave ablation, are widely used as curative treatment options for patients with small HCC, but their effectiveness remains restricted because of the associated high rate of recurrence, occurring in about 70% of patients at five years. These thermal ablation techniques have the particularity to induce immunomodulation by destroying tumours, although this is not sufficient to raise an effective antitumour immune response. Ablative therapies combined with immunotherapies could act synergistically to enhance antitumour immunity. This review aims to understand the different immune changes triggered by radiofrequency ablation and microwave ablation as well as the interest in using immunotherapies in combination with thermal ablation techniques as a tool for complementary immunomodulation.

Available ablation energies to treat cT1 renal cell cancer: emerging technologies.

PURPOSE: An increasing interest in percutaneous ablation of renal tumors has been caused by the increasing incidence of SRMs, the trend toward minimally invasive nephron-sparing treatments and the rapid development of local ablative technologies. In the era of shared decision making, patient preference for non-invasive treatments also leads to an increasing demand for image-guided ablation. Although some guidelines still reserve ablation for poor surgical candidates, indications may soon expand as evidence for the use of the two most validated local ablative techniques, cryoablation (CA) and radiofrequency ablation (RFA), is accumulating. Due to the collaboration between experts in the field in biomedical engineering, urologists, interventional radiologists and radiation oncologists, the improvements in ablation technologies have been evolving rapidly in the last decades, resulting in some new emerging types of ablations. METHODS: A literature search was conducted to identify original research articles investigating the clinical outcomes of new emerging technologies, percutaneous MWA, percutaneous IRE and SABR, in patients with primary cT1 localized renal cell cancer. RESULTS: Due to the collaboration between experts in the field in biomedical engineering, urologists, interventional radiologists and radiation oncologists, the improvements in ablation technologies have been evolving rapidly in the last decades. New emerging technologies such as microwave ablation (MWA), irreversible electroporation (IRE) and stereotactic ablative radiotherapy (SABR) seem to be getting ready for prime time. CONCLUSION: This topical paper describes the new emerging technologies for cT1 localized renal cell cancer and investigates how they compare to CA and RFA.

Cortical GABA in migraine with aura -an ultrashort echo magnetic resonance spectroscopy study.

OBJECTIVE: The aim of this cross-sectional study was to investigate the cortical metabolite concentrations in patients suffering from migraine with aura (MWA). We hypothesized that occipital γ-aminobutyric acid (GABA) levels are lower in MWA patients. BACKGROUND: Recent studies have indicated that a disturbance in the inhibitory GABA is involved in triggering the migraine aura. We aimed to explore this using a novel magnetic resonance spectroscopy sequence. METHODS: Using spin echo full intensity acquired localized spectroscopy on a Siemens 3 Tesla magnetic resonance scanner, we obtained occipital and parietal metabolite concentrations in 14 patients suffering from migraine with aura and a group of 16 matched healthy subjects. All scans were performed at Aarhus University Hospital, at the Center for Functionally Integrative Neuroscience (CFIN). RESULTS: No difference was found in GABA/(Total creatine) levels in either the occipital cortex (p = 0.744) or in the somatosensory cortex (p = 0.305). CONCLUSION: These findings indicate that cortical GABA levels are normal in patients suffering from relatively few migraine attacks. Previous studies have reported that cortical GABA in patients with more frequent migraines is reduced; further investigation of the inhibitory system in migraine patients is warranted to determine the underlying mechanisms.

Colorectal liver metastases: surgery versus thermal ablation (COLLISION) - a phase III single-blind prospective randomized controlled trial.

BACKGROUND: Radiofrequency ablation (RFA) and microwave ablation (MWA) are widely accepted techniques to eliminate small unresectable colorectal liver metastases (CRLM). Although previous studies labelled thermal ablation inferior to surgical resection, the apparent selection bias when comparing patients with unresectable disease to surgical candidates, the superior safety profile, and the competitive overall survival results for the more recent reports mandate the setup of a randomized controlled trial. The objective of the COLLISION trial is to prove non-inferiority of thermal ablation compared to hepatic resection in patients with at least one resectable and ablatable CRLM and no extrahepatic disease. METHODS: In this two-arm, single-blind multi-center phase-III clinical trial, six hundred and eighteen patients with at least one CRLM (≤3 cm) will be included to undergo either surgical resection or thermal ablation of appointed target lesion(s) (≤3 cm). Primary endpoint is OS (overall survival, intention-to-treat analysis). Main secondary endpoints are overall disease-free survival (DFS), time to progression (TTP), time to local progression (TTLP), primary and assisted technique efficacy (PTE, ATE), procedural morbidity and mortality, length of hospital stay, assessment of pain and quality of life (QoL), cost-effectiveness ratio (ICER) and quality-adjusted life years (QALY). DISCUSSION: If thermal ablation proves to be non-inferior in treating lesions ≤3 cm, a switch in treatment-method may lead to a reduction of the post-procedural morbidity and mortality, length of hospital stay and incremental costs without compromising oncological outcome for patients with CRLM. TRIAL REGISTRATION: NCT03088150 , January 11th 2017.

State of the ablation nation: a review of ablative therapies for cure in the treatment of hepatocellular carcinoma.

Primary liver cancer, mainly hepatocellular carcinoma, is one of the most common malignancies worldwide. Surgical management, either resection or transplantation, is considered definitive treatment, however, less than 20% of patients are ultimately candidates. Thermal ablation modalities such as radiofrequency ablation and microwave ablation have evolved such that these modalities have been applied with curative intent. Moreover, thermal ablation has demonstrated efficacy in treating early-stage tumors and can be offered as first-line treatment in patients with uncomplicated disease. Attributing to refinements in technology and techniques, recent studies evaluating stereotactic ablative body radiotherapy have shown promising results, while irreversible electroporation, an emerging modality, may further expand the role of ablative therapy in treating potentially resectable hepatocellular carcinoma.

Ablation therapy of non-colorectal cancer lung metastases: retrospective analysis of tumour response post-laser-induced interstitial thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA).

PURPOSE: To retrospectively compare the local tumour response and survival rates in patients with non-colorectal cancer lung metastases post-ablation therapy using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA). MATERIAL AND METHODS: Retrospective analysis of 175 computed tomography (CT)-guided ablation sessions performed on 109 patients (43 males and 66 females, mean age: 56.6 years). Seventeen patients with 22 lesions underwent LITT treatment (tumour size: 1.2-4.8 cm), 29 patients with 49 lesions underwent RFA (tumour size: 0.8-4.5 cm) and 63 patients with 104 lesions underwent MWA treatment (tumour size: 0.6-5 cm). CT scans were performed 24-h post-therapy and on follow-up at 3, 6, 12, 18 and 24 months. RESULTS: The overall-survival rates at 1-, 2-, 3- and 4-year were 93.8, 56.3, 50.0 and 31.3% for patients treated with LITT; 81.5, 50.0, 45.5 and 24.2% for patients treated with RFA and 97.6, 79.9, 62.3 and 45.4% for patients treated with MWA, respectively. The mean survival time was 34.14 months for MWA, 34.79 months for RFA and 35.32 months for LITT. In paired comparison, a significant difference could be detected between MWA versus RFA (p = 0.032). The progression-free survival showed a median of 23.49 ± 0.62 months for MWA,19.88 ± 2.17 months for LITT and 16.66 ± 0.66 months for RFA (p = 0.048). The lowest recurrence rate was detected in lesions ablated with MWA (7.7%; 8 of 104 lesions) followed by RFA (20.4%; 10 of 49 lesions) and LITT (27.3%; 6 of 22 lesions) p value of 0.012. Pneumothorax was detected in 22.16% of MWA ablations, 22.73% of LITT ablations and 14.23% of RFA ablations. CONCLUSION: LITT, RFA and MWA may provide an effective therapeutic option for non-colorectal cancer lung metastases with an advantage for MWA regarding local tumour control and progression-free survival rate.

Percutaneous microwave ablation (MWA) increased the serum levels of VEGF and MMP-9 in Stage I non-small cell lung cancer (NSCLC).

BACKGROUND: Lung cancer is the leading cause of cancer death around the world. Percutaneous microwave ablation (MWA) is an emerging treatment strategy for medically inoperable early-stage non-small cell lung cancer (NSCLC). In this study, we investigated the association of MWA and serum angiogensis promoters VEGF and MMP-9 in these patients subgroup. METHODS: We enrolled 52 patients with Stage I NSCLC patients in this study. For each patient, blood samples were drawn by venous puncture, one immediately prior to MWA and the others on Post-Procedure Days (PPD) 1, 3, 5, 7, 10 and 14. Serum samples were analysed for VEGF and MMP-9 levels with use of commercially available enzyme-linked immunosorbent assay. Also, blood samples of 28 healthy volunteers were set as the healthy controls. RESULTS: We did not observe a significant difference of serum VEGF and MMP-9 between NSCLC patients and healthy controls. The VEGF levels increased on the first day (256.0 ± 6.16 pg/ml, p < 0.05) after MWA and peaked on the PPD3 (418.0 ± 14.54 pg/ml, p < 0.05). Although it gradually reduced afterwards, its levels on PPD14 (141.2 ± 4.41 pg/ml, p < 0.05) was still higher than pre-procedure level. The serum MMP-9 level was significantly elevated from PPD1 (231.3 ± 7.93 ng/ml, p < 0.05) until PPD10 (155.3 ± 5.62 ng/ml, p < 0.05), while it normalised to pre-procedure level on PPD14 (90.78 ± 3.36 ng/ml, p > 0.05). The highest MMP-9 level was observed on PPD5 (399.7 ± 17.70 ng/ml, p < 0.05). CONCLUSION: Our preliminary results indicated that percutaneous MWA resulted in increased serum levels of VEGF and MMP-9 in Stage I NSCLC patients. Antiangiogenesis approaches may be helpful for patients defending against metastases during the immediate post-ablation time window.

The impact of frequency on the performance of microwave ablation.

PURPOSE: The use of higher frequencies in percutaneous microwave ablation (MWA) may offer compelling interstitial antenna design advantages over the 915 MHz and 2.45 GHz frequencies typically employed in current systems. To evaluate the impact of higher frequencies on ablation performance, we conducted a comprehensive computational and experimental study of microwave absorption and tissue heating as a function of frequency. METHODS: We performed electromagnetic and thermal simulations of MWA in ex vivo and in vivo porcine muscle at discrete frequencies in the 1.9-26 GHz range. Ex vivo ablation experiments were performed in the 1.9-18 GHz range. We tracked the size of the ablation zone across frequency for constant input power and ablation duration. Further, we conducted simulations to investigate antenna feed line heating as a function of frequency, input power, and cable diameter. RESULTS: As the frequency was increased from 1.9 to 26 GHz the resulting ablation zone dimensions decreased in the longitudinal direction while remaining relatively constant in the radial direction; thus at higher frequencies the overall ablation zone was more spherical. However, cable heating at higher frequencies became more problematic for smaller diameter cables at constant input power. CONCLUSION: Comparably sized ablation zones are achievable well above 1.9 GHz, despite increasingly localised power absorption. Specific absorption rate alone does not accurately predict ablation performance, particularly at higher frequencies where thermal diffusion plays an important role. Cable heating due to ohmic losses at higher frequencies may be controlled through judicious choices of input power and cable diameter.

Is there a need for MRI within 24 hours after CT-guided percutaneous thermoablation of the liver?

BACKGROUND: Radiofrequency (RFA) and microwave ablation (MWA) are established minimally invasive techniques for treatment of hepatic tumors. PURPOSE: To compare technical success and accuracy of hepatic thermoablation using computed tomography (CT) and magnetic resonance imaging (MRI) acquired 24 h after ablation with regard to evaluation of the post-interventional ablation zone and local tumor recurrence (LTR), and to assess whether additional MRI within 24 h is beneficial. MATERIAL AND METHODS: Thirty-two patients (23 men, 9 women; mean age, 60 years) with 48 lesions were included in this retrospective study. CT was performed immediately and MRI was performed 24 h after ablation. Diameter and volume calculations of the ablation zone were compared (T-Test). Technical success and ablation margin distinction, shape, and configuration were evaluated (κ-statistic). Local effectiveness was calculated based on follow-up imaging. Technical success and ablation margin features were correlated with LTR (log-rank test, Fisher's exact test). RESULTS: Ablation zone volumes were significantly higher with MRI compared to CT (P < 0.05; mean volume, 55.19 and 45.97 mL). Agreement between CT and MRI for technical success was good (κ = 0.801) and for margin conspicuity fair (κ = 0.289). LTR was 26.1% (mean follow-up, 11.7 months). LTR showed no correlation with technical success or margin conspicuity. CONCLUSION: CT and MRI are suited for early evaluation of technical success after thermoablation. Within 24 h a significant increase of the ablation volume is observed, which has to be taken into account when interpreting immediate postprocedural imaging and treating lesions near critical structures. Additional MRI 24 h after ablation seems of limited value regarding prognosis of LTR, especially with regards to evaluation of ablation margin shape and conspicuity.

Threatment Strategies for Recurrent Hepatocellular Carcinoma Patients: Ablation and its Combination Patterns.

With the development of guidance technology and ablation equipment, ablative procedures have emerged as important loco-regional alternatives to surgical resection for recurrent hepatocellular carcinoma (rHCC) patients. Currently, ablation modalities used in clinical practice mainly include radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA), cryoablation (CRA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE). Accumulated comparative data of ablation versus surgical resection reveal noninferior responses and outcomes but superior adverse effects. Moreover, studies demonstrate that ablation may serve as an excellent procedure for rHCC given its exact minimal invasiveness and immune modulation. We focus on the current status of ablation in clinical practice for rHCC and discuss new research in the field, including ablation combined with these other modalities, such as targeted therapy and immunotherapy.

Exploring the impact of variable power outputs on the efficacy and safety during microwave ablation for lung carcinoma: a real-world study.

Background: Microwave ablation (MWA) is an important method for the treatment of lung cancer, but there is still a lack of standard guidelines for the selection of power. This study aimed to explore the effectiveness and safety of MWA at different power levels. Methods: The study gathered individuals underwent MWA for lung cancer between January 2012 and December 2020. All patients were divided into low power group and high power group based on the power of MWA. By intergroup comparisons, we clarified the differences between the two groups. Results: In this study, 265 participants were involved, with 192 in the low power group and 73 in the high power group. Compared to the low power group, the high power group had a significantly higher incidence of postoperative complications (63.0% vs. 24.0%). In the Kaplan-Meier analysis, overall survival (OS) and disease-free survival (DFS) of the high power group were both better than the low power group. We found through Cox regression analysis that smoking, tumor volume, tumor differentiation, gene mutation, neutrophil count, and lymphocyte count were independent factors affecting the OS of patients. Based on the above factors, we constructed a nomogram, with areas under the curve (AUCs) of 0.941, 0.903, and 0.905 for predicting 1-, 2-, and 3-year OS after MWA, respectively. Conclusions: While high-power MWA brings better long-term prognosis to patients, it also leads to an increase in postoperative complications. The application of a nomogram for stratifying the prognosis of patients may be a more feasible approach to further develop individualized treatment plans.