Endovenous thermal ablation in the treatment of large great saphenous veins of diameters > 12 mm: A systematic review meta-analysis and meta-regression.

BACKGROUND: We sought to assess the safety and efficacy of endovenous thermal ablation (EVTA) in treating large great saphenous veins (GSV) > 12 mm in diameter. METHODS: We performed a systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 for comparative and noncomparative studies depicting EVTA in the treatment of GSV > 12 mm. Primary endpoints included GSV occlusion, technical success, deep vein thrombosis (DVT), and endovenous heat-induced thrombosis (EHIT). We conducted a comparative analysis between GSV > 12 mm and < 12 mm and a meta-regression analysis for two sets of studies, one including the whole dataset, containing treatment arms of comparative studies with GSV < 12 mm and one exclusively for GSV > 12 mm. RESULTS: Seven studies, including 2564 GSV, depicting radiofrequency (RFA) and endovenous laser ablation (EVLA) were included. GSV > 12 mm occlusion, technical success, DVT, and EHIT estimates were 95.9% (95% CI: 93.6-97.8), 99.9% (95% CI: 98.9-100.0), 0.04% (95% CI: 0.0-3.4), and 1.6% (95% CI: 0.3-3.5). Meta-regression revealed a negative association between GSV diameter and occlusion for both the whole dataset (p < 0.01) and the > 12 mm groups (p = 0.04), GSV diameter and technical success for both groups (p < 0.01), (p = 0.016), and GSV diameter and EHIT only for the whole dataset (p = 0.02). The comparative analysis between GSV < 12 mm and GSV > 12 mm displayed an occlusion estimate of OR 1.79 (95% CI: 1.25-2.56) favoring small GSV. CONCLUSION: Whereas we have displayed excellent occlusion and technical success results for the EVTA of GSV > 12 mm, our analysis has illustrated the unfavorable impact of GSV diameter on occlusion, technical success, and EHIT outcomes regardless of the 12 mm threshold. Potential parameter or device adjustments in a diameter-oriented fashion could further enhance outcomes.

Liver resection versus radiofrequency ablation in octogenarian patients for hepatocellular carcinoma: a propensity score multicenter analysis.

BACKGROUND: Liver resection (LR) and radiofrequency ablation (RFA) are considered curative options for hepatocellular carcinoma (HCC). The aim of this study was to compare outcomes after LR and RFA in octogenarian patients with HCC. MATERIALS AND METHODS: This multicenter retrospective study included 102 elderly patients (> 80 years old) treated between January 2009 and January 2019, who underwent LR or RFA for HCC (65 and 37 with, respectively). RESULTS: After Propensity Score Matching, the postoperative course of LR was burdened by a higher rate of complications than RFA group (64% vs 14%, respectively, p: 0.001). The LR group had also significantly longer operative time (207 ± 85 min vs 33 ± 49 min, p < 0.001) and postoperative hospital stays than the RFA group (7 d vs 2 d, p = 0.019). Overall survival at 1-, 2-, and 3-year were 86%, 86%, and 70% for the LR group and 82%, 64%, and 52% for the RFA group (p = 0.380). Disease-free survival at 1-, 2-, and 3-year were 89%, 74%, and 56% for the LR group, and 51%, 40%, and 40% for the RFA group (p = 0.037). CONCLUSION: Despite a higher rate of Dindo-Clavien I-II post-operative complications, a longer operative time and length of hospital stay, LR in octogenarian patients can provide comparable 90d mortality than RFA and better long-term outcomes.

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations-a cadaveric study.

INTRODUCTION: Given the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens. METHODS: Fifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated. RESULT: The accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively. CONCLUSION: It is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

Perpendicular catheter orientation during papillary muscle ablation results in larger, deeper lesions.

INTRODUCTION: Ablation of papillary muscles (PMs) for refractory ventricular arrhythmias can often be challenging. The catheter approach and orientation during ablation may affect optimal radiofrequency (RF) delivery. Yet, no previous study investigated the association between catheter orientation and PM lesion size. We evaluated ablation lesion characteristics with various catheter orientations relative to the PM tissue during open irrigated ablation, using a standardized, experimental setting. METHODS: Viable bovine PM was positioned on a load cell in a circulating saline bath. RF ablation was performed over PM tissue at 50 W, with the open irrigated catheter positioned either perpendicular or parallel to the PM surface. Applied force was 10 g. Ablation lesions were sectioned and underwent quantitative morphometric analysis. RESULTS: A catheter position oriented directly perpendicular to the PM tissue resulted in the largest ablation lesion volumes and depths compared with ablation with the catheter parallel to PM tissue (75.26 ± 8.40 mm3 vs. 34.04 ± 2.91 mm3 , p < .001) and (3.33 ± 0.18 mm vs. 2.24 ± 0.10 mm, p < .001), respectively. There were no significant differences in initial impedance, peak voltage, peak current, or overall decrease in impedance among groups. Parallel catheter orientation resulted in higher peak temperature (41.33 ± 0.28°C vs. 40.28 ± 0.24°C, p = .003), yet, there were no steam pops in either group. CONCLUSION: For PM ablation, catheter orientation perpendicular to the PM tissue achieves more effective and larger ablation lesions, with greater lesion depth. This may have implications for the chosen ventricular access approach, the type of catheter used, consideration for remote navigation, and steerable sheaths.

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.

Risk factors for the recurrence of early hepatocellular carcinoma treated by percutaneous radiofrequency ablation with a multiple-electrode switching system: a multicenter prospective study.

PURPOSE: To investigate the long-term efficacy of radiofrequency ablation (RFA) with a multiple-electrode switching system (MESS) in the treatment of early hepatocellular carcinoma (HCC) and evaluate the patterns and risk factors of intrahepatic recurrence of HCC after RFA. METHODS: In total, 139 patients with early HCC who underwent RFA with MESS as primary treatment at multiple centers were prospectively enrolled according to the inclusion criteria. We evaluated the local tumor progression (LTP), intrahepatic distant recurrence (IDR), the incidence of cumulative disease-free survival (DFS), LTP-free survival, IDR-free survival, and overall survival. We also analyzed the associated risk factors. RESULTS: A total of 139 patients were included in the study and the median follow-up time was 64 months, ranging from 11 to 72 months. The complete ablation rate was 98.56%. Sixty-nine (49.64%) were found to have intrahepatic recurrence (LTP, n = 15; IDR, n = 55) during follow-up. The 1-year, 3-year and 5-year cumulative DFS, LTP-free survival, and IDR-free survival rates were 74.82, 94.46 and 78.75%; 54.68, 88.03 and 61.79%; and 51.80, 85.67 and 60.17%, respectively. In the multivariable analysis, tumor size > 4 cm was the only important risk factor for LTP. The alkaline phosphatase (ALP) level and the number of tumors were independent risk factors for IDR; α-fetoprotein (AFP) level > 400 µg/L and recurrence interval were risk factors for the overall survival period. CONCLUSIONS: The MESS-RFA is an effective method for local control of tumors in early HCC. Early HCC with multiple high-ALP tumors has a higher rate of recurrence, which mainly occurs in an IDR pattern. Early HCC with high AFP levels and a shorter initial recurrence interval resulted in a poorer prognosis. Thus, treatments such as liver transplantation or surgical resection may be a good strategy in those cases. CLINICALTRIALS.GOV ID: NCT02046356.

Quality appraisal of clinical practice guidelines for the use of radiofrequency ablation in the treatment of thyroid nodules and cancer.

INTRODUCTION: Radiofrequency ablation (RFA) has gained significant recent global interest in the treatment of benign thyroid nodules and thyroid cancer. It is a relatively new, minimally invasive, thermal ablation technique that is an alternative to surgery. Several clinical practice guidelines (CPGs), consensus statements, and recommendations currently exist for the use of RFA in the treatment of benign thyroid nodules and thyroid cancers. These documents have considerable variability amongst them, and to date, their quality and methodologic rigor have not been appraised. OBJECTIVE: To identify and perform a quality appraisal of clinical practice guidelines for RFA in the treatment of benign thyroid nodules and thyroid cancer using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. METHODS: A comprehensive literature search was performed in MEDLINE (via PubMed), EMBASE, and SCOPUS databases from inception to November 1, 2021. Four reviewers independently evaluated each guideline using the AGREE II instrument. Scaled domain scores were generated and the threshold used for satisfactory quality was >60%. Additionally, intraclass correlation coefficients (ICCs) were calculated to determine level of agreement between reviewers. RESULTS: Seven guidelines were selected for final evaluation based on inclusion/exclusion criteria. Two guidelines were classified "high" quality, one "average" quality, and the rest "low" quality. The "Clarity and Presentation" (65.68 ± 26.1) and "Editorial Independence" (61.32 ± 25.8) domains received the highest mean scores, while the "Applicability" (32.14 ± 22.8) and "Rigor of Development" (45.02 ± 29.8) domains received the lowest mean scores. ICC statistical analysis showed high magnitude of agreement between reviewers with a range of (0.722-0.944). CONCLUSION: Reflecting upon our quality appraisal, it is evident that the quality and methodologic rigor of RFA guidelines can be improved upon in the future. Our findings also elucidate the existing variability/discrepancies amongst guidelines in the indications and use of RFA.

AC measurements and simulations of hepatic radiofrequency ablation.

INTRODUCTION: The radiofrequency ablation (RFA) of liver cancer is a desirable treatment option, as it is minimally invasive. An accurate numerical simulation can greatly help physicians better plan their surgical protocols. Previously, the displacement current in the RFA process was considered negligible, and therefore RFA simulation was modeled as a direct current (DC) system instead of an alternating current (AC) system. Our study investigated the hypothesis that the displacement current in the RFA process should not always be considered negligible. METHODS: AC measurements of ex vivo bovine liver ablation were performed, and numerical simulations were also conducted to test the hypothesis that the relative permittivity would significantly decrease after the liver tissue reached a high temperature. RESULTS: The displacement current was observed to be a sizable fraction of the conduction current, especially before the onset of the first pause. The simulation results indicated that the relative permittivity is likely to decrease to several hundred or lower at elevated temperatures. CONCLUSIONS: Our study results suggest that the DC model may be inadequate, especially before the first roll-off and that additional information could be available during RFA treatment by considering the AC nature of RFA, which could lead to improved numerical simulation. Additional measurements of tissue parameters are needed to reach the full potential of the AC model for further development of ablation control.

Correlation and agreement between superb micro-vascular imaging and contrast-enhanced ultrasound for assessing radiofrequency ablation treatment of thyroid nodules: a preliminary study.

BACKGROUND: To evaluate the correlation and agreement between superb micro-vascular imaging (SMI) mode and the contrast-enhanced ultrasound (CEUS) mode for the ablative completeness and the volumes of ablation lesions to determine the clinical application value of SMI in follow-up after radiofrequency ablation. METHODS: From April 2020 to June 2020, two radiologists used SMI and CEUS mode to measure the volume of the ablation lesion. We use intra-class correlation coefficient (ICC), scatter plots and Bland-Altman plots to evaluate the correlation and agreement of the two techniques. In addition, intra- and inter-observer reliability in volume measurement of ablation lesions with SMI mode was assessed. RESULTS: SMI mode and CEUS mode have good agreement in the evaluation of ablative completeness. The ICC was 0.876 and 0.928 of reader A and reader B between SMI mode and CEUS mode in terms of ablation lesions volume measurement. There was a strong correlation between the two modes in both reader A and reader B (rA = 0.808; rB = 0.882). The ICC was 0.836 for the inter-observer reliability of SMI technique. The scatter plot showed a good linear relation (r = 0.715). In the Bland-Altman plot, 4.35% (1/23) of the points was outside the 95% limits of agreement. The ICC was 0.965 for the intra-observer reliability of SMI technique, the scatter plot also showed a strong linear correlation (r = 0.965). In the Bland-Altman plot, 8.70% (2/23) of the points was outside the 95% limits of agreement. CONCLUSIONS: SMI and CEUS have good agreement and correlation in the ablation volume measurement. SMI technology is expected to be applied as an alternative to CEUS in the clinical follow-up of ablation lesions.

Rescue radiofrequency ablation or percutaneous ethanol injection: a strategy for failed RALPPS stage-1 in patients with cirrhosis-related hepatocellular carcinoma.

BACKGROUND: The future liver remnant (FLR) faces a risk of poor growth in patients with cirrhosis-related hepatocellular carcinoma (HCC) after stage-1 radiofrequency-assisted ALPPS (RALPPS). The present study presents a strategy to trigger further FLR growth using supplementary radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI). METHODS: At RALPPS stage-1 the portal vein branch was ligated, followed by intraoperative RFA creating a coagulated avascular area between the FLR and the deportalized lobes. During the interstage period, patients not achieving sufficient liver size (≥ 40%) within 2-3 weeks underwent additional percutaneous RFA/PEI of the deportalized lobes (rescue RFA/PEI) in an attempt to further stimulate FLR growth. RESULTS: Seven patients underwent rescue RFA/PEI after RALPPS stage-1. In total five RFAs and eight PEIs were applied in these patients. The kinetic growth rate (KGR) was highest the first week after RALPPS stage-1 (10%, range - 1% to 15%), and then dropped to 1.5% (0-9%) in the second week (p < 0.05). With rescue RFA/PEI applied, KGR increased significantly to 4% (2-5%) compared with that before the rescue procedures (p < 0.05). Five patients proceeded to RALPPS stage-2. Two patients failed: In one patient the FLR remained at a constant level even after four rescue PEIs. The other patient developed metastasis. Except one patient died after RALPPS stage-2, no severe complications (Clavien-Dindo ≥ IIIb) occurred among remaining six patients. CONCLUSIONS: Rescue RFA/PEI may provide an alternative to trigger further growth of the FLR in patients with cirrhosis-related HCC showing insufficient FLR after RALPPS stage-1. Trial registration Retrospectively registered.

Patient satisfaction of radiofrequency ablation for symptomatic benign solid thyroid nodules: our experience for 2-year follow up.

BACKGROUND: The patient satisfaction of symptoms improvement and disease factors that may affect long-term treatment efficacy of radiofrequency ablation (RFA) for non-functioning solid benign thyroid nodules (TNs) over a 2-year follow up study was investigated. METHODS: This retrospective study evaluated 194 non-functioning solid benign TNs of 103 patients. The TNs were categorized as small (≤5 ml), medium (5.1 to 13 ml), intermediate (13.1 to 30 ml) and large (over 30 ml) according to the initial volume of TNs before ablation. Clinical evaluation and contrast-enhanced ultrasound (CEUS) were carried out before ablation and the follow up at 1, 3, 6 months and every 6 months after ablation. All patients were asked to assess the cosmetic score (1-4 scores) and symptom score (0-10 scores) before ablation and every follow up after ablation. RESULTS: All patients underwent RFA without any major complications. The mean treatment sessions were 1.5 ± 0.6. 98 nodules required a single session (98/194, 50.5%), 87 required two sessions (87/194, 44.9%), 9 required three sessions (9/194, 4.6%). The average follow up months were 16.3 ± 5.6 (range, 6-24 months) and no nodule regrew in our study. After RFA treatment, the TNs volume significantly decreased (P < 0.001). The small group of nodules shrunk larger compared to the medium, intermediate and large groups (P < 0.001). Cosmetic signs and pressure symptoms were significantly improved, particularly in the intermediate and large groups (P < 0.05). CONCLUSIONS: RFA is effective for treating non-functioning solid benign TNs and controlling clinical symptoms with a low complication rate during 2 years follow up. The reduction rate was related to the initial volume of nodules. Patients were satisfied with cosmetic signs and pressure symptoms improvement, particularly in the intermediate and large groups. However, multiple RFA treatments should be used in larger nodules to achieve the desired clinical outcomes.

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.

Efficacy and safety of radiofrequency ablation for treatment of chronic radiation proctitis: A systematic review and meta-analysis.

BACKGROUND AND AIM: Although argon plasma coagulation is the current standard endoscopic treatment for chronic radiation proctitis (CRP), radiofrequency ablation (RFA) has emerged as an attractive alternative. The aim of this study is to evaluate the efficacy and safety of RFA for the treatment of CRP. METHODS: Searches of PubMed, EMBASE, Web of Science, and Cochrane Library databases were performed from 2004 through March 2018. Review and data abstraction were performed independently by two authors. Measured outcomes included hemoglobin, transfusion dependence, number of treatment sessions, RFA settings, and serious adverse events. RESULTS: Six studies (n = 71; mean age 73.41 ± 1.88 years; 90.14% male) were included. Thirty-eight percent of patients failed prior treatment with argon plasma coagulation. Patients underwent a mean of 1.71 ± 0.34 RFA sessions with 24.54 ± 16.47 RFA applications per session. Pooled clinical and endoscopic success of RFA was 99% (95% confidence interval [CI]: 90-100; P < 0.001) and 100% (95% CI: 94-100; P < 0.001), respectively. Serious adverse events were reported in one patient-pooled rate of 0% (95% CI: 0-3; P < 0.001). Mean pre-procedure hemoglobin was 10.38 ± 1.82 g/dL with significant improvement observed post-RFA [weighted mean difference 2.49 g/dL (95% CI: 2.16-2.82; P < 0.001)]. Among transfusion-dependent patients, 85% (95% CI: 68-97; P < 0.001) became transfusion-free post-RFA. Pooled mean follow-up was 19.73 ± 9.72 months. CONCLUSION: Despite limited long-term data on RFA for CRP, available evidence suggests RFA is an effective and safe treatment.

Measuring Barrett's Epithelial Thickness with Volumetric Laser Endomicroscopy as a Biomarker to Guide Treatment.

BACKGROUND: Radiofrequency ablation (RFA) treatment outcomes vary for unknown reasons. One hypothesis is that variations in Barrett's epithelial thickness (BET) are associated with reduced RFA efficacy for thicker BET and strictures for thinner BET. Volumetric laser endomicroscopy (VLE) is an imaging modality that acquires high-resolution, depth-resolved images of BE. However, the attenuation of light by tissue and the lack of layering in Barrett's tissue challenge BET measurements and the study of relationships between thickness and RFA outcomes. We aimed to quantify BET and compared the reliability of standard and contrast-enhanced VLE images. METHODS: Baseline VLE scans from BE patients without prior ablative therapy and a Prague (M) length of > 1 cm were obtained from the US VLE Registry. An algorithm was applied to the VLE images to flatten the mucosal surface and enhance the contrast of different esophageal wall layers. Subsequently, BET was measured by two independent VLE readers using both contrast- and non-contrast-enhanced datasets. In order to validate these adjusted images, intra- and interobserver agreements were calculated. RESULTS: VLE scans from fifty-seven patients were included in this study. BET was measured at eight equidistant locations on the selected cross-sectional images at 0.5 cm intervals from the GEJ to the proximal-most extent of BE. The intra-observer coefficients of the two readers for the contrast-enhanced images were 0.818 (95% CI 0.798-0.836) and 0.890 (95% CI 0.878-0.900). The interobserver agreement for the contrast-enhanced images (0.880; 95% CI 0.867-0.891) was significantly better than for the original images (0.778; 95% CI 0.754-0.799). CONCLUSION: We developed an algorithm that improves VLE visualization of the mucosal layers of the esophageal wall and enables rapid and reliable measurement of BET. Interobserver variability measurements were significantly reduced when using contrast enhancement. Studies are underway to correlate BET with treatment response.

Multimodal radiofrequency ablation versus laparoscopic hepatic resection for the treatment of primary hepatocellular carcinoma within Milan criteria in severely cirrhotic patients: long-term favorable outcomes over 10 years.

BACKGROUND: Less invasiveness is an important consideration for the treatment of hepatocellular carcinoma (HCC) especially in patients with severe cirrhosis. METHODS: Between April 2000 and September 2016, 100 patients with liver damage B underwent multimodal radiofrequency ablation (RFA; n = 62) or laparoscopic hepatic resection (Lap-HR; n = 38) for primary HCC as defined by the Milan criteria. We compared the operative outcomes and patients' survival between the two groups. RESULTS: The RFA group showed worse liver functions as indicated by indocyanine green retention rate (32.9 vs. 22.4%; p < 0.0001) and serum albumin value (3.3 vs. 3.6 g/dl; p = 0.0029). As expected, RFA was less invasive, as indicated by the differences in operation time (166 vs. 288 min.; p < 0.0001) and blood loss (8 vs. 377 g; p < 0.0001). There was no significant difference in the morbidity rate between the two groups; however, the duration of hospital stay of the RFA group was significantly shorter (7 vs. 11 days; p = 0.0002). There were no significant between-group differences regarding overall or disease-free survival. CONCLUSION: Multimodal RFA for HCC in patients with severe cirrhosis is associated with less invasiveness and shorter hospital stays, with no compromise in the patients' survival. In patients with severe cirrhosis, it may be time to consider changing the standard treatment for primary HCC within the Milan criteria to multimodal RFA.

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.

Efficacy of combination therapy with transcatheter arterial chemoembolization and radiofrequency ablation for intermediate-stage hepatocellular carcinoma.

OBJECTIVES: Transcatheter arterial chemoembolization (TACE) is the standard therapy for patients with intermediate-stage hepatocellular carcinoma (HCC). This study aimed to determine whether combination therapy with radiofrequency ablation (RFA) and TACE was superior to TACE monotherapy for intermediate-stage HCC and identify cases in which this technique was the most effective. MATERIALS AND METHODS: We selected patients with intermediate HCC who met the following eligibility criteria: (1) ≥ 20 years of age, (2) receiving initial therapy, (3) ≤7 tumors, and (4) maximum tumor diameter <5 cm. We performed propensity score matching (PSM) using potential confounding factors. We retrospectively compared the cumulative overall survival rate and recurrence-free survival rate between the TACE + RFA and TACE groups. Additionally, a sub-group analysis was performed for preoperative factors. RESULTS: Among the 103 patients, 92 were selected using PSM. The cumulative overall survival rates at 1, 3, and 5 years for the TACE + RFA group were 97.4%, 70.4%, and 60.4%, respectively, which were significantly higher than those for the TACE group (92.7%, 55.7%, and 22.8%, respectively, p = .045). The recurrence-free survival rates at 0.5, 1, and 2 years for the TACE + RFA group were 80.0%, 58.6%, and 33.3%, respectively, which were significantly higher than those for the TACE group (34.5%, 8.8%, and 2.9%, respectively, p < .01). For the sub-group with α-fetoprotein (AFP) <100 ng/mL, the TACE + RFA group demonstrated a significantly improved prognosis than the TACE group (p = .036). CONCLUSIONS: The addition of RFA to TACE improved cumulative overall and recurrence-free survival in patients with intermediate-stage HCC, especially in patients with AFP <100.

Numerical study to establish relationship between coagulation volume and target tip temperature during temperature-controlled radiofrequency ablation.

The present study aims at proposing a relationship between the coagulation volume and the target tip temperature in different tissues (viz., liver, lung, kidney, and breast) during temperature-controlled radiofrequency ablation (RFA). A 20-min RFA has been modelled using commercially available monopolar multi-tine electrode subjected to different target tip temperatures that varied from 70°C to 100°C with an increment of 10°C. A closed-loop feedback proportional-integral-derivative (PID) controller has been employed within the finite element model to perform temperature-controlled RFA. The coagulation necrosis has been attained by solving the coupled electric field distribution, the Pennes bioheat and the first-order Arrhenius rate equations within the three-dimensional finite element model of different tissues. The computational study considers temperature-dependent electrical and thermal conductivities along with the non-linear piecewise model of blood perfusion. The comparison between coagulation volume obtained from the numerical and in vitro experimental studies has been done to evaluate the aptness of the numerical models. In the present study, a total of 20 numerical simulations have been performed along with 12 experiments on tissue-mimicking phantom gel using RFA device. The study revealed a strong dependence of the coagulation volume on the pre-set target tip temperature and ablation time during RFA application. Further, the effect of target tip temperature on the applied input voltage has been studied in different tissues. Based on the results attained from the numerical study, statistical correlations between the coagulation volume and treatment time have been developed at different target tip temperatures for each tissue.

Comparative effectiveness of first-line radiofrequency ablation versus surgical resection and transplantation for patients with early hepatocellular carcinoma.

BACKGROUND: Significant controversy exists as to which treatment modality is most effective for small, solitary hepatocellular carcinomas (HCCs): radiofrequency ablation (RFA), surgical resection (RXN), or transplantation (TXP). Size cutoff values ranging from 20 to 50 mm have been proposed to achieve complete ablation. The current study compares outcomes between RFA, RXN, and TXP as first-line therapy for patients with HCC tumors measuring as large as 50 mm. METHODS: The Surveillance, Epidemiology, and End Results database was queried for patients with HCC tumors measuring up to 50 mm who were treated with RFA, RXN, or TXP between 2004 and 2013. Overall survival (OS) and disease-specific survival (DSS) were examined in patients with tumors measuring ≤20 mm, 21 to 30 mm, or 31 to 50 mm. The impact of an increase in tumor size of only 5 mm beyond 30 mm was evaluated by also examining outcomes in patients with tumors measuring 31 to 35 mm. RESULTS: Of 1894 cases, patients with HCC tumors measuring ≤20 mm and 21 to 30 mm demonstrated no difference in OS or DSS regardless of whether RFA and RXN was used. RFA was associated with a worse OS and DSS than TXP, whereas there was no difference in OS observed between RXN and TXP. In patients with tumors measuring 31 to 50 mm, OS and DSS were worse with RFA compared with RXN or TXP. Most important, the inferior DSS and OS noted with RFA were observed with only a 5-mm increase in tumors measuring >30 mm. CONCLUSIONS: Although RFA frequently is used as first-line treatment of HCC tumors measuring as large as 50 mm, it is associated with worse results than RXN or TXP for tumors measuring >30 mm. To the best of the authors' knowledge, the results of the current study are the first to demonstrate that although RFA is an appropriate option for patients with HCC tumors measuring ≤30 mm, its use for tumors even slightly larger than 30 mm is associated with inferior outcomes. Cancer 2017;123:1817-1827. © 2017 American Cancer Society.

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.