Liver resection is superior to tumor ablation in patients with multifocal hepatocellular carcinoma.

INTRODUCTION: The management of T2 multifocal hepatocellular carcinoma (MHCC) is controversial, and the comparative impact of liver resection (LR) versus tumor ablation (TA) on survival continues to be debated. The aim of our study was to examine short- and long-term survival for LR and TA in a nationally representative cohort. We hypothesized that patients who underwent LR would have improved survival. METHODS: We utilized the National Cancer Database (2004-2015) to identify patients diagnosed with non-metastatic T2 MHCC. Kaplan-Meier survival curves were generated to compare 10-year overall survival (OS) between LR and TA patients. Kaplan-Meier analysis with stratification was also performed based on lymphovascular invasion, resection margin status, and Charlson-Deyo score. Cox proportional hazard models were used in multivariable analyses. RESULTS: A total of 1225 patients met the inclusion criteria. 991 patients received LR, and 234 received TA. The majority of patients were male, White, and older than ≥60 years old. Clinicodemographic characteristics were generally similar between LR and TA patients. Among patients who underwent LR, 84% had negative margins, and 17% had lymphovascular invasion. Mortality at 30 days was significantly higher among LR patients compared to TA patients (5.4% vs 0.0%, p < 0.001), with those having a Charlson-Deyo score ≥2 facing the highest risk at 7.3%. Nevertheless, 10-year OS for the LR cohort was 27.5% (95% confidence interval [CI]: 24.4%-30.8%) versus 14.7% (95% CI: 9.8%-20.7%, p < 0.001) for TA patients. In stratified analysis, survival benefit was statistically significant only among those with negative resection margin, no lymphovascular invasion, and Charlson-Deyo score ≤1. In multivariable Cox analysis, LR was independently associated with improved survival compared to TA (hazard ratio: 0.80; 95% CI = 0.67-0.95). CONCLUSION: LR poses a higher long-term survival benefit than TA. Prospective studies are warranted to confirm these findings. Although our study patients are a highly selected group of multifocal T2 patients, it gives us a good insight into the fact that LR provides better outcomes if a transplant option is unavailable.

TACE sequential MWA guided by cone-beam computed tomography in the treatment of small hepatocellular carcinoma under the hepatic dome.

PURPOSE: An assessment is being conducted to determine the safety and effectiveness of using Cone-beam computed tomography (CBCT)-guided transcatheter arterial chemoembolization (TACE) and microwave ablation (MWA) sequentially to treat small hepatocellular carcinomas (HCCs) located in the hepatic dome. MATERIALS AND METHODS: Fifty-three patients with small HCCs in the hepatic dome who underwent TACE combined with simultaneous CBCT-guided MWA were studied. Inclusion criteria were a single HCCs ≤ 5.0 cm or a maximum of three. The safety and interventional-related complications were monitored, and local tumor progression (LTP), overall survival (OS), and prognostic factors for LTP/OS were evaluated. RESULTS: The procedures were successfully accomplished in all patients. According to Common Terminology Criteria for Adverse Events (CTCAE), adverse reactions and complications are mainly Grade 1 or 2 (mild symptoms, no or local/noninvasive intervention indicated). Liver and kidney function and alpha-fetoprotein (AFP) levels remained within a reasonable range after 4 weeks of treatment (both p < 0.001). The mean LTP was 44.406 months (95% CI: 39.429, 49.383) and the mean OS rate was 55.157 months (95% CI: 52.559, 57.754). The combination treatment achieved 1-, 3-, and 5-year LTP rates of 92.5%, 69.6%, and 34.5%, respectively; and 1-, 3-, and 5-year OS rates of 100.0%, 88.4%, and 70.2%, respectively. Results from both univariate and multivariate Cox regression analyses showed that the tumor diameter (< 3 cm) and the distance to the hepatic dome (≥ 5 mm, < 10 mm) had a significant impact on the patient's LTP and OS, and were related to better survival. CONCLUSION: CBCT-guided TACE combined with simultaneous MWA was a safe and successful treatment of HCCs located under the hepatic dome.

Introduction to interventional radiology's role in palliative care for children with cancer: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

As palliative care continues to be an area of increasing emphasis in pediatric oncology programs, it is important to raise awareness about minimally invasive, image-guided procedures that can supplement more conventional palliative interventions, such as systemic analgesics, external beam radiation, and locoregional anesthesia. These procedures, when performed for appropriately selected patients, can often facilitate discharge from an inpatient facility, and help patients meet their end-of-life goals. This article specifically discusses three palliative procedures performed by interventional radiologists that can assist pediatric palliative care teams in: (a) percutaneous thermal ablation of painful bone metastases, (b) cryoneurolysis, and (c) tunneled drainage catheter placement for malignant pleural effusions and ascites.

Computational modeling of microwave ablation with thermal accelerants.

PURPOSE: To develop a computational model of microwave ablation (MWA) with a thermal accelerant gel and apply the model toward interpreting experimental observations in ex vivo bovine and in vivo porcine liver. METHODS: A 3D coupled electromagnetic-heat transfer model was implemented to characterize thermal profiles within ex vivo bovine and in vivo porcine liver tissue during MWA with the HeatSYNC thermal accelerant. Measured temperature dependent dielectric and thermal properties of the HeatSYNC gel were applied within the model. Simulated extents of MWA zones and transient temperature profiles were compared against experimental measurements in ex vivo bovine liver. Model predictions of thermal profiles under in vivo conditions in porcine liver were used to analyze thermal ablations observed in prior experiments in porcine liver in vivo. RESULTS: Measured electrical conductivity of the HeatSYNC gel was ∼83% higher compared to liver at room temperature, with positive linear temperature dependency, indicating increased microwave absorption within HeatSYNC gel compared to tissue. In ex vivo bovine liver, model predicted ablation zone extents of (31.5 × 36) mm with the HeatSYNC, compared to (32.9 ± 2.6 × 40.2 ± 2.3) mm in experiments (volume differences 4 ± 4.1 cm3). Computational models under in vivo conditions in porcine liver suggest approximating the HeatSYNC gel spreading within liver tissue during ablations as a plausible explanation for larger ablation zones observed in prior in vivo studies. CONCLUSION: Computational models of MWA with thermal accelerants provide insight into the impact of accelerant on MWA, and with further development, could predict ablations with a variety of gel injection sites.

Investigating cell death responses associated with histotripsy ablation of canine osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most frequently occurring primary bone tumor in dogs and people and innovative treatment options are profoundly needed. Histotripsy is an emerging tumor ablation modality, and it is essential for the clinical translation of histotripsy to gain knowledge about the outcome of nonablated tumor cells that could remain postablation. The objective of this study was to characterize the cell death genetic signature and proliferation response of canine OS cells post a near complete histotripsy ablation (96% ± 1.5) and to evaluate genetic cell death signatures associated with histotripsy ablation and OS in vivo. METHODS: In the current study, we ablated three canine OS cell lines with a histotripsy dose that resulted in near complete ablation to allow for a viable tumor cell population for downstream analyses. To assess the in vivo cell death genetic signature, we characterized cell death genetic signature in histotripsy-ablated canine OS tumors collected 24-h postablation. RESULTS: Differential gene expression changes observed in the 4% viable D17 and D418 cells, and histotripsy-ablated OS tumor samples, but not in Abrams cells, were associated with immunogenic cell death (ICD). The 4% viable OS cells demonstrated significantly reduced proliferation, compared to control OS cells, in vitro. CONCLUSION: Histotripsy ablation of OS cell lines leads to direct and potentially indirect cell death as evident by, reduced proliferation in remaining viable OS cells and cell death genetic signatures suggestive of ICD both in vitro and in vivo.

The Synergistic Effect of Interventional Locoregional Treatments and Immunotherapy for the Treatment of Hepatocellular Carcinoma.

Immunotherapy has remarkably revolutionized the management of advanced HCC and prompted clinical trials, with therapeutic agents being used to selectively target immune cells rather than cancer cells. Currently, there is great interest in the possibility of combining locoregional treatments with immunotherapy for HCC, as this combination is emerging as an effective and synergistic tool for enhancing immunity. On the one hand, immunotherapy could amplify and prolong the antitumoral immune response of locoregional treatments, improving patients' outcomes and reducing recurrence rates. On the other hand, locoregional therapies have been shown to positively alter the tumor immune microenvironment and could therefore enhance the efficacy of immunotherapy. Despite the encouraging results, many unanswered questions still remain, including which immunotherapy and locoregional treatment can guarantee the best survival and clinical outcomes; the most effective timing and sequence to obtain the most effective therapeutic response; and which biological and/or genetic biomarkers can be used to identify patients likely to benefit from this combined approach. Based on the current reported evidence and ongoing trials, the present review summarizes the current application of immunotherapy in combination with locoregional therapies for the treatment of HCC, and provides a critical evaluation of the current status and future directions.

Unveiling Mechanism of Organic Photogenerator for Hydroxyl Radicals Generation by Molecular Modulation.

Photodynamic therapy (PDT) with organic photosensitizers generally goes through the oxygen-dependent process, generating singlet oxygen and/or superoxide anion. However, the generation of reactive oxygen species is often suppressed as a result of hypoxia, one of the common features in tumors, therefore limiting the effectiveness of the tumor treatments. Consequently, it is urgent and significant to develop an oxygen-independent hydroxyl radical photogenerator and unveil the mechanism. In this work, a hydroxyl radical (·OH) photogenerator originating from the electron transfer process is engineered. Detailed mechanism studies reveal that the optimized photosensitizer, WS2D, which contains a bithiophene unit, could both promote charge carrier generation and accelerate reaction efficiency, resulting in the efficient production of ·OH. In addition, WS2D nanoparticles are constructed to improve the polydispersity and stability in aqueous solution, which exhibit excellent biocompatibility and mitochondrial targeting. Bearing the above advantages, WS2D is employed in phototheranostics, which could release ·OH effectively and damage mitochondria precisely, achieving high PDT efficiency in vitro and in vivo. Overall, this work successfully provides valuable insights into the structural design of a hydroxyl radicals (·OH) photogenerator with great practical perspectives.

Proton Resonance Frequency Shift Thermometry: A Review of Modern Clinical Practices.

Magnetic resonance imaging (MRI) has become a popular modality in guiding minimally invasive thermal therapies, due to its advanced, nonionizing, imaging capabilities and its ability to record changes in temperature. A variety of MR thermometry techniques have been developed over the years, and proton resonance frequency (PRF) shift thermometry is the current clinical gold standard to treat a variety of cancers. It is used extensively to guide hyperthermic thermal ablation techniques such as high-intensity focused ultrasound (HIFU) and laser-induced thermal therapy (LITT). Essential attributes of PRF shift thermometry include excellent linearity with temperature, good sensitivity, and independence from tissue type. This noninvasive temperature mapping method gives accurate quantitative measures of the temperature evolution inside biological tissues. In this review, the current status and new developments in the fields of MR-guided HIFU and LITT are presented with an emphasis on breast, prostate, bone, uterine, and brain treatments. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Focused ultrasound for the treatment of glioblastoma.

PURPOSE: Six years ago, in 2015, the Focused Ultrasound Foundation sponsored a workshop to discuss, and subsequently transition the landscape, of focused ultrasound as a new therapy for treating glioblastoma. METHODS: This year, in 2021, a second workshop was held to review progress made in the field. Discussion topics included blood-brain barrier opening, thermal and nonthermal tumor ablation, immunotherapy, sonodynamic therapy, and desired focused ultrasound device improvements. RESULTS: The outcome of the 2021 workshop was the creation of a new roadmap to address knowledge gaps and reduce the time it takes for focused ultrasound to become part of the treatment armamentarium and reach clinical adoption for the treatment of patients with glioblastoma. Priority projects identified in the roadmap include determining a well-defined algorithm to confirm and quantify drug delivery following blood-brain barrier opening, identifying a focused ultrasound-specific microbubble, exploring the role of focused ultrasound for liquid biopsy in glioblastoma, and making device modifications that better support clinical needs. CONCLUSION: This article reviews the key preclinical and clinical updates from the workshop, outlines next steps to research, and provides relevant references for focused ultrasound in the treatment of glioblastoma.

Microwave Ablation for Malignant Central Airway Obstruction: A Pilot Study.

BACKGROUND: Malignant central airway obstruction (CAO) is a debilitating complication of primary lung cancer and pulmonary metastases. Therapeutic bronchoscopy is used to palliate symptoms and/or bridge to further therapy. Microwave ablation (MWA) heats tissue by creating an electromagnetic field around an ablation device. We present a pilot study utilizing endobronchial MWA via flexible bronchoscopy as a novel modality for the management of malignant CAO. METHODS: Therapeutic bronchoscopy with a flexible MWA probe was performed in 8 cases. We reviewed tumor size, previous ablative techniques, number of applications, ablation time, amount of energy delivered, rate of successful recanalization, complications, and 30-day follow-up. RESULTS: Successful airway recanalization was achieved in all cases. No complications were noted. In 1 case, tumor in-growth within a silicone stent was ablated with no damage to the stent. DISCUSSION: Endobronchial MWA is a novel technique for tumor destruction while maintaining an airway axis. The oven effect and air gap around a tumor allow for safe and effective tissue devitalization and hemostasis without a thermal effect on structures surrounding the airway.

Percutaneous ablation or minimally invasive partial nephrectomy for cT1a renal masses? A propensity score-matched analysis.

OBJECTIVE: Local tumor ablation to treat small renal mass is increasing. The aim of the present study was to compare oncologic outcomes among patients with T1 renal mass treated with partial nephrectomy and local tumor ablation. METHODS: To reduce the inherent differences between patients undergoing laparoscopic or robot-assisted partial nephrectomy (n = 405) and local tumor ablation (n = 137), we used a 1:1 propensity score-matched analysis. Local tumor ablation consisted of radiofrequency ablation and cryoablation. Disease-free survival, overall survival and other causes mortality-free survival rates were estimated using the Kaplan-Meier method. Multivariable logistic regression and competing-risk regression models were used to identify predictors of complications, recurrence and other causes mortality, respectively. RESULTS: Partial nephrectomy had higher disease-free survival estimates, as compared with local tumor ablation (92.8% vs 80.4% at 5 years, P = 0.02), with no significant difference between radiofrequency ablation and cryoablation (P = 0.9). Ablation showed comparable overall survival estimates to partial nephrectomy (91% vs 95.8% at 5 years, P = 0.6). The 5-year recurrence rates were 7.9% versus 23.8% for patients aged ≤70 years, and 2.5% versus 11.9% for patients aged >70 years treated with partial nephrectomy and ablation, respectively; the 5-year other causes mortality rates were 0% and 2.2% for patients treated with partial nephrectomy and ablation aged ≤70 years, and 3% versus 10.9% for patients aged >70 years treated with partial nephrectomy and ablation, respectively. At multivariable analysis, ablation was associated with fewer complications (odds ratio 0.41; P = 0.01). At competing risks analysis, age (hazard ratio 0.96) and ablation (hazard ratio 4.56) were independent predictors of disease recurrence (all P ≤ 0.008). CONCLUSIONS: Local tumor ablation showed a higher risk of recurrence and lower risk of complications compared with partial nephrectomy, with comparable overall survival rates.

Benefitial role of electrochemotherapy in locally advanced pancreatic cancer - radiological perspective.

Irreversible electroporation (IRE) of locally advanced pancreatic cancer is an increasingly used method for unresectable pancreatic cancer that can be used in cytoreduction followed by surgical treatment and shows promising results in palliative care. IRE is an ablative technique where electric pulses cause damage to the cell membrane leading to apoptosis without the destruction of stroma. The application of IRE increases the concentration of hydrophobic regimens like bleomycin within the tumor, what could improve the effectiveness of treatment. This fusion of those two treatments is called electrochemotherapy. In this review, the authors will discuss the radiological perspective of possible beneficial role of irreversible electroporation in relation with chemotherapy in pancreatic cancer treatment.

Polyethylenimine (PEI)-modified poly (lactic-co-glycolic) acid (PLGA) nanoparticles conjugated with tumor-homing bacteria facilitate high intensity focused ultrasound-mediated tumor ablation.

The acoustic propagation characteristic of ultrasound determines that the energy of ultrasound beam will decrease with the increase of its propagation depth in the body. Similarly, the energy of High Intensity Focused Ultrasound (HIFU) will be attenuated with the increase of HIFU propagation depth in the body. Ensuring sufficient ultrasound energy deposition in the HIFU ablation region for tumor ablation is usually achieved by increasing the ultrasound irradiation power or prolonging the ultrasound ablation time. However, these two methods may damage the normal tissue adjacent to the HIFU ablation region. Herein, we constructed the nanoparticles conjugated with tumor-homing bacteria as the biological tumor-homing synergist to facilitate HIFU-mediated tumor ablation avoiding the potential safety risk. In our strategy, Bifidobacterium bifidum (B.bifidum) was selectively colonized in the hypoxic region of solid tumors after been injected into 4T1 breast cancer bearing-BALB/c mice via the tail vein due to its anaerobic growth characteristic. The amount of B. bifidum with negative surface potential in the hypoxic region of solid tumors was increased by its anaerobic proliferation. Polyethylenimine (PEI) -modified Poly (lactic-co-glycolic) acid nanoparticles loaded sodium bicarbonate (PEI-PLGA-NaHCO3-NPs) with positive surface potential injected into 4T1 breast cancer bearing-BALB/c mice via the tail vein displayed the tumor-homing ability by the electrostatic adsorption with B. bifidum colonized solid tumors. PEI-PLGA-NaHCO3-NPs could release NaHCO3 to produce carbon dioxide (CO2) as cavitation nuclei inside the acidic microenvironment of solid tumors. When HIFU irradiated solid tumors contained with more cavitation nuclei, the ultrasound energy deposition at the tumor region was increased to destroy the tumors more effectively. Meanwhile, the improved efficiency of HIFU-mediated tumor ablation reduced the dependence of the tumor ablation on the ultrasound energy dose, which improved the safety of HIFU-mediated tumor ablation to the non-targeted ablation tissue. This tumor-homing synergist shows the potential application value on the HIFU-mediated tumor ablation in the clinical.

Assessing ablation margins of FDG-avid liver tumors during PET/CT-guided thermal ablation procedures: a retrospective study.

BACKGROUND: To retrospectively assess liver tumor ablation margins using intraprocedural PET/CT images from FDG PET/CT-guided microwave or cryoablation procedures and to correlate minimum margin measurements with local progression outcomes. METHODS: Fifty-six patients (ages 36 to 85, median 62; 32 females) with 77 FDG-avid liver tumors underwent 60 FDG PET/CT guided, percutaneous microwave, or cryoablation procedures. Single breath-hold PET/CT images were used for intraprocedural assessment of the tumor ablation margin: liver tumors remained visible on PET immediately following ablation; microwave ablation zones were visible using contrast-enhanced CT; cryoablation zones (ice balls) were visible using unenhanced CT. Two readers retrospectively determined ablation margin assessability and measured the minimum ablation margin on intraprocedural PET/CT (n = 77) and postprocedural MRI (n = 56). Local tumor progression was assessed on all available follow-up imaging (1-49 months, mean 15). Local tumor progression was correlated with PET/CT minimum margin measurements using clustered survival models for 61 tumors. RESULTS: Minimum ablation margins were more often assessable using intraprocedural PET/CT (≥ 73/77 tumors, 95%) than postprocedural MRI (≤ 35/56 tumors, 63%). In 61 tumors with PET/CT-assessable margins (excluding tumors with overlapping ablations after PET/CT), there was a 6-fold increased risk of local tumor progression [hazard ratio (HR) 6.05; P = 0.004] for minimum ablation margins < 5 mm. CONCLUSION: Breath-hold PET/CT scans, during PET/CT-guided microwave or cryoablation procedures for FDG-avid liver tumors, enable reliable intraprocedural assessment of the entire tumor ablation margin; a minimum PET/CT ablation margin threshold of 5 mm correlates well with local tumor progression outcomes.

Liver tumor F-18 FDG-PET before and immediately after microwave ablation enables imaging and quantification of tumor tissue contraction.

PURPOSE: Poor liver tumor visibility after microwave ablation (MWA) limits direct tumor ablation margin assessments using contrast-enhanced CT or ultrasound (US). Positron emission tomography (PET) or PET/CT may offer improved intraprocedural assessment of liver tumor ablation margins versus current imaging techniques, as 18F-fluorodeoxyglucose (18F-FDG)-avid tumors remain visible on PET immediately following ablation. The purpose of this study was to assess intraprocedural 18F-FDG PET scans before and immediately after PET/CT-guided MWA for visualization and quantification of metabolic liver tumor tissue contraction resulting from MWA. METHODS: This retrospective study, conducted at a large academic medical center after Institutional Review Board approval, included 36 patients (20 men; mean age 63 [range 37-85]) who underwent PET/CT-guided MWA of 42 18F-FDG-avid liver tumors from May 2013 to March 2018. Tumor metabolic diameters (short/long axes) were measured for each tumor on pre- and post-ablation PET images. Tumor metabolic volumes were calculated using tumor diameter measurements and compared with automated volumes using an SUV threshold algorithm. A two-tailed paired t test was used for the analyses. RESULTS: Comparing intraprocedural pre- and post-ablation PET images, mean metabolic tumor short- and long-axis diameters decreased from 21.4 to 14.9 mm [- 29%, p < 0.001, standard deviation (SD) 18%] and from 24.0 to 18.0 mm (- 24%, p < 0.001, SD 16%), respectively. The mean calculated tumor metabolic volume decreased from 10.5 to 4.6 mm3 (- 55%, p < 0.001, SD 26%). The mean automated tumor metabolic volume decreased from 10.6 to 5.8 mm3 (- 45%, p < 0.001, SD 30%). CONCLUSION: Intraprocedural PET images of 18F-FDG-avid liver tumors allow visualization and quantification of MWA-induced metabolic tumor tissue contraction during 18F-FDG PET/CT-guided procedures. The ability to visualize contracted tumor immediately post-MWA may facilitate emerging intraprocedural PET and PET/CT imaging techniques that address a clinical gap in directly assessing the ablation margin.

Immunological effect of irreversible electroporation on hepatocellular carcinoma.

BACKGROUND: This study intends to investigate the immunological effects of tumor ablation with irreversible electroporation (IRE). METHODS: We evaluated the systemic immune response in patients with hepatocellular carcinoma (HCC) after IRE treatment. Furthermore, we analyzed the tumor infiltrating T lymphocytes and the level of serum cytokines in IRE and control groups of tumor-bearing mice. RESULTS: We observed that IRE induced an increase in WBC, neutrophil and monocyte counts and a decrease in lymphocyte count 1 day post-IRE and returned to baseline values within 7 days in the patients. Meanwhile, circulating CD4+ T cell subsets, but not CD8+, decreased 1 day post-IRE. The activated T cells and natural killer (NK) cells increased, and regulatory T (Treg) cells decreased. Furthermore, a significant increase in cytotoxic CD8+ T cells infiltration was observed on ablative tumors in mice. The level of serum IFN-γ also significantly increased in the IRE group. CONCLUSIONS: Our study demonstrated that IRE upregulated activated T cells and downregulated Tregs in the peripheral blood of patients. Meanwhile, the results from the animal model indicated that IRE could induce antitumor adaptive immunity dominated by the infiltration of cytotoxic CD8+ T cells into the tumors, accompanied by reduced Tregs.

Magnetic anchoring and guidance-assisted endoscopic irreversible electroporation for gastric mucosal ablation: a preclinical study in canine model.

BACKGROUND: The aim of this study was to evaluate the feasibility, safety, and efficacy of magnetic anchoring and guidance-assisted endoscopic irreversible electroporation (MAG-IRE) for gastric mucosal ablation. METHODS: A catheter-based, donut-like, and MAG-assisted electrode was developed. MAG-IRE for gastric mucosal ablation was performed in eight beagle canines. The parameters of one set of IRE was 500 V voltage, 100 µs pulse duration, and 99 pulses. The MAG time, operation time, success rate, and adverse events were measured. Endoscopic examination was performed from 30 min to 28 days post-IRE. Full-thickness gastric tissue was harvested by wedge biopsy for histopathological analysis. RESULTS: 30 (93.75%) of the 32 lesions were successfully ablated by MAG-IRE. The median MAG time was 300 s (IQR 120-422.5 s), and the median operation time was 491.5 s (IQR 358.3-632.5 s). No adverse events occurred. Ulceration was observed, starting from 3 days post-IRE. The mucosa healed 14 to 28 days post-IRE. Hematoxylin-Eosin (H&E) staining showed inflammatory infiltration, edema, and congestion in the ablated mucosa. Masson's Trichrome staining showed that the gastric wall and blood vessels in the ablation area were intact. TUNEL assay showed diffuse positive cells in ablated mucosa as early as 30 min post-IRE. CONCLUSIONS: MAG-IRE for gastric mucosal ablation is feasible, safe, and effective. It can be a potential therapeutic option for minimally invasive treatment of gastric neoplasm.

MRI-guided percutaneous thermoablation as first-line treatment of recurrent hepatic malignancies following hepatic resection: single center long-term experience.

PURPOSE: Hepatic recurrence of liver malignancies is a leading problem in patients after liver resection with curative intention. Thermoablation is a promising treatment approach for patients after hepatic resection, especially in liver-limited conditions. This study aimed to investigate safety, survival, and local tumor control rates of MRI-guided percutaneous thermoablation of recurrent hepatic malignancies following hepatic resection. MATERIAL AND METHODS: Data from patients with primary or secondary hepatic malignancies treated between 2004 and 2018 with MRI-guided percutaneous thermoablation of hepatic recurrence after prior hepatic resection were retrospectively analyzed. Disease-free survival and overall survival rates were calculated using the Kaplan-Meier method. RESULTS: A total of 57 patients with hepatic recurrence (mean tumor size = 18.9 ± 9.1 mm) of colorectal cancer liver metastases (n = 27), hepatocellular carcinoma (n = 17), intrahepatic recurrence of cholangiocellular carcinoma (n = 9), or other primary malignant tumor entities (n = 4) were treated once or several times with MR-guided percutaneous radiofrequency (n = 52) or microwave ablation (n = 5) (range: 1-4 times). Disease progression occurred due to local recurrence at the ablation site in nine patients (15.8%), non-local hepatic recurrence in 33 patients (57.9%), and distant malignancy in 18 patients (31.6%). The median overall survival for the total cohort was 40 months and 49 months for the colorectal cancer group, with a 5-year overall survival rate of 40.7 and 42.5%, respectively. The median disease-free survival was 10 months for both the total cohort and the colorectal cancer group with a 5-year disease-free survival rate of 15.1 and 14.8%, respectively. The mean follow-up time was 39.6 ± 35.7 months. CONCLUSION: MR-guided thermoablation is an effective and safe approach in the treatment of hepatic recurrences in liver-limited conditions and can achieve long-term survival.

Percutaneous thermal ablation of hepatic tumors: local control efficacy and risk factors for artificial ascites failure.

OBJECTIVE: To investigate the risk factors affecting the technical failure of artificial ascites (AA) formation and to evaluate the local control efficacy of percutaneous thermal ablation assisted by the AA for hepatic tumors. METHODS: A total of 341 patients with 362 hepatic tumors who underwent thermal ablation assisted by AA were reviewed retrospectively. The technical success of AA, the volume of liquid, and local efficacy after ablation were assessed. Predictive factors for the technical failure of AA formation and local tumor progression (LTP) were analyzed using univariate and multivariate analysis. RESULTS: The technical success rate of AA formation was 81.8% (296/362). The amount of fluid was higher when the tumor was located in the left lobe of the liver than when it was located in the right lobe (median 950 ml versus 700 ml, p < 0.001). Previous hepatic resection (OR: 12.63, 95% CI: 2.93-54.45, p < 0.001), ablation (OR: 6.48, 95% CI: 1.36-30.92, p = 0.019) and upper-abdomen surgery (OR: 11.34, 95% CI: 1.96-65.67, p = 0.007) were the independent risk factors of AA failure. In the AA success group, the complete ablation rate was higher and the LTP rate was lower than that in the AA failure group (98.7 versus 92.4%, p = 0.012; 8.8 versus 21.2%, p = 0.004). Multivariate analysis identified AA failure (p = 0.004), tumor size (>3.0 cm) (p = 0.002) and metastatic liver tumor (p = 0.008) as independent risk factors for LTP. CONCLUSION: History of hepatic resection, ablation and upper abdomen surgery were significant predictive factors affecting the technical failure of AA formation. Successful introduction of AA before thermal ablation can achieve better local tumor control efficacy.

Review of clinical tumor ablation advance in Asia.

Tumor ablation has been widely applied in Asia, accounting for 44.65% of clinical studies worldwide. We reviewed 5853 clinical studies to provide insight on the advance of tumor ablation in Asia chronologically and geographically among different techniques and organs. Since 1998, tumor ablation application has dramatically evolved in Asia. All kinds of ablation techniques, including percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA), cryoablation (CA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE), have been applied, with the first application of PEI and the most popular application of RFA. Twenty-five countries and one district in Asia have applied tumor ablation in various organs, including liver, lung, uterus, thyroid, kidney, pancreas, bone, prostate, breast, adrenal gland, lymph node parathyroid, esophagus, etc. Due to the high incidence of tumors as well as advanced economy and technology, East Asia accounted for 93.87% of studies, led by China (45.00%), Japan (32.72%), South Korea (12.10%), and Taiwan (4.03%). With the enrichment of evidence from large-scale multicenter and randomized control studies, China and South Korea have issued several guidelines on tumor ablation for liver, lung, and thyroid, which provided recommendations for global standardization of tumor ablation techniques. Therefore, Asia has made active contribution to global tumor ablation therapy.KeypointsKey point 1: Asia accounted for 44.65% of clinical studies worldwide on tumor ablation.Key point 2: Twenty-five countries and one district in Asia have used tumor ablation in various organs, and East Asia accounted for 93.87% of studies, led by China (45.00%), Japan (32.72%), South Korea (12.10%), and Taiwan (4.03%).Key point 3: China and South Korea have issued several guidelines on tumor ablation for liver, lung, and thyroid, which provided recommendations for global standardization of tumor ablation techniques.