Local Tumor Progression Rates Research Articles

Safety and effectiveness of balloon catheter-assisted ultrasound-guided percutaneous microwave ablation in difficult-site liver cancer

BackgroundBalloon catheter isolation is a promising auxiliary method for thermal ablation treatment of liver cancer. We aimed to explore the safety and effectiveness of balloon catheter isolation-assisted ultrasound-guided percutaneous microwave ablation (MWA) in treating liver cancer in difficult anatomical locations. MethodsData of 132 patients with 145 difficult-site liver cancer treated with ultrasound-guided percutaneous MWA were retrospectively analyzed. Participants were classified into the isolation (n = 40) and non-isolation (n = 92) groups based on whether the patients were treated using a balloon catheter prior to ablation. The major complication rates, local tumor residuals (LTR), and tumor follow-up for local tumor progression (LTP) at 6 and 12 months post-ablation were compared between the two groups. ResultsThe rates of major postoperative complications did not significantly differ between the isolation and non-isolation groups (2.5% vs. 4.3%, P = 0.609). The postoperative LTR rates were significantly different between the isolation and non-isolation groups (4.8% vs. 17.5%, P = 0.032). Balloon catheter isolation [odds ratio (OR) = 0.225, 95% confidence interval (CI): 0.085-0.595, P = 0.009] and tumor diameter (OR = 2.808, 95% CI: 1.186-6.647, P = 0.019) were identified as independent factors influencing LTR rate. The cumulative LTP rates at 6 and 12 months after ablation showed no significant differences between the isolation and non-isolation groups (2.6% vs. 7.9%, P = 0.661; 4.9% vs. 9.8%, P = 0.676, respectively). Cox proportional hazards regression analysis showed that tumor diameter was an independent risk factor for cumulative LTP rate (OR = 3.445, 95% CI: 1.406-8.437, P = 0.017). ConclusionsBalloon catheter isolation-assisted MWA was safe and effective in the treatment of difficult-site liver cancer. Additionally, tumor diameter significantly influenced LTR and LTP rates after ablation.

The combination of transarterial chemoembolization and microwave ablation is superior to microwave ablation alone for liver metastases from colorectal cancer

ObjectivesThis study aimed to compare the combination therapy of transarterial chemoembolization (TACE) and microwave ablation (MWA) with MWA alone in treating liver metastases from colorectal cancer (LMCRC).Materials and methodsIn this retrospective study, a total of 251 patients with unresectable and not to chemotherapy responding LMCRC were included. Group A consisted of 184 patients (104 male and 80 females; mean age: 64 ± 11.4 years) with 442 metastases who received a combination of TACE and MWA. A total of 67 patients (49 male and 18 females; mean age: 63.2 ± 11.8 years) with 173 metastases patients were included in group B, who received only MWA. Parameters assessed were local tumor progression (LTP), hepatic distant tumor progression (hDTP), hepatic progression-free survival (hPFS), and overall survival (OS).ResultsThe rate of LTP was 4.9% in group A and 4.5% in group B (p-value: 0.062). The rate of hDTP was 71.7% and 83.6% for groups A and B (p-value: 0.81), respectively. The mean hPFS was 13.8 months (95% CI 10.9–16.8) for group A and 8.1 months (95% CI 6.1–10.1) for group B (p-value: 0.03). The median OS time for group A was 30 months (95% CI 26–34), with 1-, 2-, 3-, and 4-year OS rates of 84.2%, 61.1%, 40.8% and 31.3%, respectively. In group B however, the median OS time was 26 months (95% CI 18–34) with 1-, 2-, 3-, and 4-year OS rates of 82.3%, 53.2%, 34.6% and 28.2%, respectively (p-value: 0.67).ConclusionThe combination therapy of TACE and MWA is superior to the monotherapy of MWA for LMCRC, especially regarding hDTP, hPFS and OS.

Identification of A0 minimum ablative margins for colorectal liver metastases: multicentre, retrospective study using deformable CT registration and artificial intelligence-based autosegmentation.

Several ablation confirmation software methods for minimum ablative margin assessment have recently been developed to improve local outcomes for patients undergoing thermal ablation of colorectal liver metastases. Previous assessments were limited to single institutions mostly at the place of development. The aim of this study was to validate the previously identified 5 mm minimum ablative margin (A0) using autosegmentation and biomechanical deformable image registration in a multi-institutional setting. This was a multicentre, retrospective study including patients with colorectal liver metastases undergoing CT- or ultrasound-guided microwave or radiofrequency ablation during 2009-2022, reporting 3-year local disease progression (residual unablated tumour or local tumour progression) rates by minimum ablative margin across all institutions and identifying an intraprocedural contrast-enhanced CT-based minimum ablative margin associated with a 3-year local disease progression rate of less than 1%. A total of 400 ablated colorectal liver metastases (median diameter of 1.5 cm) in 243 patients (145 men; median age of 62 [interquartile range 54-70] years) were evaluated, with a median follow-up of 26 (interquartile range 17-40) months. A total of 119 (48.9%) patients with 186 (46.5%) colorectal liver metastases were from international institutions B, C, and D that were not involved in the software development. Three-year local disease progression rates for 0 mm, >0 and <5 mm, and 5 mm or larger minimum ablative margins were 79%, 15%, and 0% respectively for institution A (where the software was developed) and 34%, 19%, and 2% respectively for institutions B, C, and D combined. Local disease progression risk decreased to less than 1% with an intraprocedurally confirmed minimum ablative margin greater than 4.6 mm. A minimum ablative margin of 5 mm or larger demonstrates optimal local oncological outcomes. It is proposed that an intraprocedural minimum ablative margin of 5 mm or larger, confirmed using biomechanical deformable image registration, serves as the A0 for colorectal liver metastasis thermal ablation.

Comparison of Radiofrequency Ablation and Microwave Ablation for the Management of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Hepatocellular carcinoma (HCC) is a common critical type of hepatic cancer worldwide. Recent guidelines have considered ablative therapeutic approaches as the primary option for managing early-stage surgically untreatable HCC. Among these therapies, radiofrequency ablation (RFA) and microwave ablation (MWA) have attained a significant role due to their efficacy and theoretical advantages. This review aims to compare and analyze the efficacy and safety of two common modalities, i.e., MWA and RFA, in the management of HCC. The literature search included PubMed, Cochrane Central Register of Controlled Trials, Medline, and Ovid for articles published until 2024. The outcomes included the local tumor progression (LTP), complete ablation (CA), the overall survival (OS) rate, or major complications. A meta-analysis was performed using Review Manager 5.3. The systematic review included six randomized controlled trials, including 826 patients. The findings revealed that MWA resulted in lower LTP and higher CA rates compared to RFA. However, the effect of complications was higher in the MWA therapy group. Despite that, the differences between all parameters were not significant. Statistical significance was not evident in the OS rates between the two modalities. Three studies found comparable survival rates between the two modalities, while one study reported similar local tumor recurrence-free survival rates between the two approaches. Both techniques appear to be effective and safe for the management of liver tumors, providing clinicians with valuable options for personalized patient care. Further high-quality research is needed to confirm these findings and guide clinical decision-making.

Feasibility and safety study of ultrasound-guided percutaneous microwave ablation for sub-cardiac liver cancers without artificial ascites assistance.

To investigate the efficacy and safety of ultrasound (US)-guided microwave ablation (MWA) without artificial ascites (AA) inpatients with sub-cardiac (SC) liver cancers. This retrospective study included patients with the left lobe and caudate lobe of the liver cancer who underwent US-guided MWA in our institute from January 2020 to December 2022. According to whether the target lesion was located ≤5 mm from the pericardium, patients were divided into the SC group and the non-sub-cardiac (NSC) group. In the SC group, AA was not employed during the ablation procedure. The results of technical success, technical efficiency, local tumour progression (LTP), and major complications were recorded. A total of 79 patients with 87 lesions were enrolled. There were 38 patients with 38 lesions in the SC group and 41 patients with 49 lesions in the NSC group. The median follow-up of all patients was 15 (range, 3-44) months. There was no significant difference in technical success rates (100% vs 100%), technique efficiency rates (100% vs 95.7%), LTP rates (2.63% vs 0%,), and major complication rates (2.63% vs 7.32%) between the SC group and the NSC group (P > .05). No cardiac-related complications occurred. US-guided MWA without AA for SC liver cancers was safe and effective. The clinical prognosis of thermal ablation without AA in the treatment of SC liver cancers is still unclear. The finding of this study provided evidence supporting the efficacy and safety of US-guided MWA without AA for treating this tricky location.

Incremental high power radiofrequency ablation with multi-electrodes for small hepatocellular carcinoma: a prospective study

Radiofrequency ablation (RFA) offers a minimally invasive treatment for small hepatocellular carcinoma (HCC), but it faces challenges such as high local recurrence rates. This prospective study, conducted from January 2020 to July 2022, evaluated a novel approach using a three-channel, dual radiofrequency (RF) generator with separable clustered electrodes to improve RFA’s efficacy and safety. The study employed a high-power, gradual, stepwise RFA method on HCCs (≤ 4 cm), utilizing real-time ultrasound-computed tomography (CT)/magnetic resonance imaging (MRI) fusion imaging. Involving 110 participants with 116 HCCs, the study reported no major complications. Local tumor progression (LTP) and intrahepatic remote recurrence (IRR) rates were low, with promising cumulative incidences at 1, 2, and 3 years for LTP (0.9%, 3.6%, 7.0%) and IRR (13.9%, 20.5%, 31.4%). Recurrence-free survival (RFS) rates were similarly encouraging: LTP (99.1%, 96.4%, 93.0%) and IRR (86.1%, 79.5%, 68.6%). This innovative gradual, incremental high-power RFA technique, featuring a dual switching monopolar mode and three electrodes, represents an effective and safer management option for small HCCs.Trial registrationclinicaltrial.gov identifier: NCT05397860, first registered on 26/05/2022.

Comparison of the Efficacy of Percutaneous Microwave Ablation Therapy versus Laparoscopic Partial Nephrectomy for Early-Stage Renal Tumors.

This study aimed to compare the efficacy of percutaneous microwave ablation therapy (MWAT) and laparoscopic partial nephrectomy (LPN) in early-stage renal cell carcinoma (RCC) classified as T1a; a retrospective analysis was conducted on patients treated between January 2017 and November 2023. Oncological outcomes, radiological recurrence, length of stay (LOS), and costs were evaluated. The study included 110 patients, with no significant differences between the two groups regarding residual tumors, local tumor progression, and disease-free survival rates (p > 0.05). The LPN group showed significantly lower pre/postoperative serum urea and creatinine and higher estimated glomerular filtration rate values, whereas the MWA group experienced significantly lower mean costs, complication rates, LOS in the hospital, and procedure durations (p ≤ 0.05). However, post-procedure residual tumors and local tumor progression rates did not differ significantly between the LPN and MWAT groups (p > 0.05). MWAT is as effective as LPN for T1a RCC lesions. In addition, MWAT has lower costs than LPN and is a cost-effective treatment method. Therefore, MWAT minimizes hospital stay and complications and since the oncological results are similar to LPN, it might be considered as the first choice of treatment in young patients.

Effectiveness and safety of sequential transarterial chemoembolization and microwave ablation for subphrenic hepatocellular carcinoma: A comprehensive evaluation.

Subphrenic carcinoma has been identified as a significant risk factor for the thermal ablation of intrahepatic tumors, resulting in a high rate of residual tumor recurrence. Some studies have proposed that combination treatment with transarterial chemoembolization (TACE) followed by radiofrequency ablation is both feasible and safe for tumors in the subphrenic region. However, research specifically examining the therapeutic outcomes of combination therapy using TACE and microwave ablation (TACE-MWA) in subphrenic tumors is lacking. To evaluate the efficacy and safety of TACE-MWA in patients with subphrenic hepatocellular carcinoma (HCC). Between December 2017 and December 2021, 49 patients diagnosed with HCC ≤ 6 cm, who received TACE-MWA, were included in this retrospective cohort study. These patients were classified into subphrenic and non-subphrenic groups based on the distance between the diaphragm and the tumor margin. The rates of local tumor progression (LTP), progression-free survival (PFS), and overall survival (OS) were compared between the two groups. Complications were evaluated by using a grading system developed by the Society of Interventional Radiology. After a median follow-up time of 38 mo, there were no significant differences in LTP between the subphrenic and non-subphrenic groups (27.3% and 22.2% at 5 years, respectively; P = 0.66), PFS (55.5% at 5 years in both groups; P = 0.91), and OS (85.0% and 90.9% in the subphrenic and non-subphrenic groups at 5 years; P = 0.57). However, a significantly higher rate of LTP was observed in subphrenic HCC > 3 cm compared to those ≤ 3 cm (P = 0.085). The dosage of iodized oil [hazard ratio (HR): 1.52; 95% confidence interval (CI): 1.11-2.08; P = 0.009] and multiple tumors (HR: 13.22; 95%CI: 1.62-107.51; P = 0.016) were independent prognostic factors for LTP. There were no significant differences in complication rates between the two groups (P = 0.549). Combined TACE and MWA was practical and safe for managing subphrenic HCC. The efficacy and safety levels did not vary significantly when tumors outside the subphrenic region were treated.

Ablation of Small Liver Metastases Presenting as Foci of Diffusion Restriction on MRI-Results from the Prospective Minimally Invasive Thermal Ablation (MITA) Study.

Liver metastases presenting as small hyperintense foci on diffusion-weighted imaging (DWI) pose a therapeutic challenge. Ablation is generally not possible since these lesions are often occult on ultrasound and CT. The purpose of this prospective study was to assess if small liver metastases (≤10 mm) detected on DWI can be successfully localized and ablated with the Hepatic Arteriography and C-Arm CT-Guided Ablation technique (HepACAGA). All consecutive patients with small liver metastases (≤10 mm), as measured on DWI, referred for ablation with HepACAGA between 1 January 2021, and 31 October 2023, were included. Re-ablations and ablations concomitant with another local treatment were excluded. The primary outcome was the technical success rate, defined as the intraprocedural detection and subsequent successful ablation of small liver metastases using HepACAGA. Secondary outcomes included the primary and secondary local tumor progression (LTP) rates and the complication rate. A total of 15 patients (26 tumors) were included, with liver metastases from colorectal cancer (73%), neuro-endocrine tumors (15%), breast cancer (8%) and esophageal cancer (4%). All 26 tumors were successfully identified, punctured and ablated (a technical success rate of 100%). After a median follow-up of 9 months, primary and secondary LTP were 4% and 0%, respectively. No complications occurred. In this proof-of-concept study, the HepACAGA technique was successfully used to detect and ablate 100% of small liver metastases identified on DWI with a low recurrence rate and no complications. This technique enables the ablation of subcentimeter liver metastases detected on MRI.

Radiofrequency Ablation in Patients with Interstitial Lung Disease and Lung Neoplasm: A Retrospective Multicenter Study

PurposeTo retrospectively investigate the safety and effectiveness of percutaneous radiofrequency (RF) ablation by analyzing results in patients with lung neoplasm accompanied by interstitial lung disease (ILD) on computed tomography (CT) in a multicenter study. Materials and MethodsPatients with lung neoplasm accompanied by ILD who underwent RF ablation between April 2002 and October 2017 at 7 institutions were investigated. Technical success rate and local tumor progression (LTP) of ablated tumors were evaluated. Adverse events including acute exacerbation of ILD were also evaluated. Univariate analyses were performed to identify factors associated with acute exacerbation. ResultsForty-nine patients with 64 lung neoplasms (mean diameter, 23 mm; range, 4–58 mm) treated in 66 sessions were included. Usual interstitial pneumonia (UIP) pattern on CT was identified in 23 patients (47%). All patients underwent successful RF ablation. Acute exacerbations were seen in 5 sessions (8%, 7% with UIP pattern and 8% without) in 5 patients, all occurring on or after 8 days (median, 12 days; range, 8–30 days). Three of those 5 patients died of acute exacerbation. Treatment resulted in mortality after 5% of sessions, representing 6% of patients. Pleural effusion and fever (temperature ≥ 38°C) after RF ablation were identified by univariate analysis (P = .001 and P = .02, respectively) as significant risk factors for acute exacerbation. The cumulative LTP rate was 43% at 1 year. ConclusionsRF ablation appears feasible for patients with lung neoplasm complicated by ILD. Acute exacerbation occurred in 8% of patients with symptoms occurring more than 8 days after ablation and was associated with a 45% mortality rate.

Value of the three-dimensional visualization ablation planning system in ultrasound-guided percutaneous microwave ablation for malignant adrenal tumors: A clinical comparative study.

We aimed to assess the efficacy and safety of the three-dimensional visualization ablation planning system (3DVAPS) in ultrasound-guided percutaneous microwave ablation (US-PMWA) for malignant adrenal tumors (MATs). A retrospective analysis was conducted on a cohort of 62 unilateral MAT cases from March 2011 to November 2022. There were a total of 62 lesions, with a mean maximum diameter of 5.4 ± 2.7 cm (range, 1.4-15.7 cm). The patients were categorized into the following, based on the pre-operative planning method: 3D planning (n = 32) and 2D planning (n = 30) groups. A comparative analysis was performed on various parameters, including ablation techniques, tumor-related prognosis, and incidence of complications. This analysis encompassed indicators, such as overall survival (OS) rate and local tumor progression (LTP), among others. The median follow-up period was 30 months (range, 3-84 months). Notably, compared with the 2D planning group, the 3D planning group exhibited significant disparities in the number of punctures (P = 0.035) and incidence of complications (P = 0.029) and had no significant difference in the OS ( P > 0.05) but had a significantly lower LTP rate (6.2% vs. 23.3%, P = 0.033). In the 3D planning group, the sub-group with a tumor diameter of < 5 cm exhibited a significantly less number of punctures ( P = 0.039), lower input energy ( P = 0.002), and a shorter ablation time ( P = 0.001), compared with the sub-group with a tumor diameter of ≥ 5 cm, but there was no significant difference in the LTP and OS rates between the two sub-groups ( P > 0.05). The use of 3DVAPS in US-PMWA of MATs was advantageous, especially in lesions with a diameter of ≥ 5 cm. It can help in developing more rational surgical plans, reducing the incidence of complications, and extending the local recurrence-free survival time of patients and can add a certain value for precise treatment and expand the indications for ablation.

A retrospective study comparing the efficacy of microwave ablation and stereotactic body radiotherapy in colorectal cancer lung metastases.

The purpose of the present study was to assess and compare the efficacy of microwave ablation (MWA) and stereotactic body radiotherapy (SBRT) in the treatment of lung metastases from patients with colorectal cancer (CRC) and to identify the preferable treatment modality based on patient and tumor characteristics. Records of 118 patients with CRC with a total of 307 lung metastases who underwent SBRT or MWA between January 2015 and December 2022 were retrospectively analyzed, including the essential clinicopathological information on patients (age, sex and underlying diseases), diagnosis and treatment information [primary tumor site, levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9], imaging data [diameter of lung metastasis, location of the metastasis (i.e., whether or not the tumor was adjacent to the vessel or bronchus) and internal features] and follow-up data (postoperative therapy, complications or adverse effects and survival outcomes). For statistical analysis of the local tumor progression (LTP), disease-free survival and overall survival (OS) rates, Cox regression analysis, along with the Kaplan-Meier method adjusted using inverse probability of treatment weighting (IPTW), were performed. The median follow-up duration in the present study was 31.5 months. Multivariable Cox regression analysis revealed that the CEA level, metastasis diameter and internal features were independent predictors of OS. In the IPTW-adjusted analysis, no significant difference in the 1-year OS rate was observed between the SBRT and MWA groups (92.9 vs. 93.9%; P=0.483); however, a notable discrepancy in the treatment modalities was noted, leading to significant differences in the 2- and 3-year OS rates (65.9 vs. 57.6%, P=0.001, and 44.7 vs. 36.4%, P<0.001, respectively). A significant interaction effect for the treatment modality was observed for LTP (P=0.021). In conclusion, the present study revealed that SBRT and MWA have similar therapeutic effects in terms of prolonging the survival of patients with CRC with lung metastases; however, regarding the local control of lung metastases, MWA is associated with a number of significant advantages.

TACE-assisted multi-image guided radiofrequency ablation for the treatment of single hepatocellular carcinoma ≤ 5cm: a retrospective study.

Treatment of hepatocellular carcinoma (HCC) with ablation alone often results in high rates of recurrence and metastasis, reaching up to 25.9% within two years. Therefore, this study aimed to examine the efficacy and safety of transarterial chemoembolization (TACE)-assisted multi-image guided radiofrequency ablation (RFA) for the treatment of stage Ia HCC according to the China liver cancer staging (CNLC). This study enrolled and analyzed a total of 118 patients diagnosed with HCC, each with a single nodular lesion no larger than 5cm, who received TACE-RFA as first-line therapy between February 1, 2014, and December 31, 2021. The median/mean follow-up period was 29.0 months [95% confidence interval (CI): 21.8-36.2 months] and 31.8 months (95% CI: 27.5-36.0 months), respectively. We assessed the treatment's effectiveness, potential complications, and survival rate. The technical success rate was 100% (118/118) after the initial treatment. Out of the total, 3 out of 118 patients (2.5%) developed local tumor progression (LTP) during the follow-up period. The median time for LTP was 29.0 months (95%CI: 21.9-36.1 months; mean: 31.5 months; range 1-92 months). At 1, 3, 5, and 7 years after treatment, the cumulative LTP rates were 0%, 4.6%, 4.6%, and 4.6%, respectively. The overall survival rates at 1, 3, 5, and 7 years were 100%, 95.2%, 95.2%, and 95.2%, respectively. In total, 28 patients experienced minor Grade B complications, and no major complications or treatment-related mortality occurred. The treatment of CNLC stage Ia HCC using TACE-assisted multi-image-guided RFA was found to be both safe and feasible.

Radiofrequency ablation of hepatocellular carcinoma guided by real-time physics-based ablation simulation: a prospective study

Objectives To assess the safety and efficacy of radiofrequency ablation (RFA) guidance software that incorporated patient-specific physics-based simulation of each ablation volume. Materials and methods Patients referred for curative ablation of hepatocellular carcinoma (HCC) of 2–5 cm diameter were prospectively enrolled. RFA was performed under general anesthesia. Procedure planning and intraprocedural modifications were guided by computer simulation of each ablation. The segmented target (tumor with 5 mm margin) was registered to and superimposed on subsequent 3D multiplanar images. The applied RF energy was used to calculate a simulated ablation volume which was displayed relative to the electrode and segmented target, to depict any untreated target tissue. After each additional ablation, the software updated the accumulated simulated ablation volume in relation to the target. The primary endpoints were technical efficacy and rate of local tumor progression (LTP). Results Sixty-eight tumors were ablated during 57 procedures in 52 patients (68.3 ± 9.2 years old, 78.8% male); 15 (26.3%) had multiple lesions and 23 (39.1%) had prior HCC treatment. The mean tumor diameter was 2.73 (±0.64) cm. The intraprocedural simulation directed additional overlapping ablations in 75.9% of tumors. Technical success and efficacy were 100% at 3-month contrast enhanced CT or MRI follow-up after the single treatment session. Cumulative incidence function estimates for 1- and 2-year LTP were 3.9% and 20.2%, respectively. Conclusion This prospective study found computer-assisted guidance that simulated each ablation was both safe and efficacious. The low rate of LTP was similar to studies that employed stereotactic guidance and ablation confirmation, without requiring a second contrast enhanced study.

Usefulness of Body Position Change during Local Ablation Therapies for the High-Risk Location Hepatocellular Carcinoma.

Local ablation therapies are important treatment options for early-stage hepatocellular carcinoma (HCC). Various techniques have been used to perform these therapies efficiently and safely. However, few reports have discussed the usefulness of body position change (BPC). This study aimed to investigate the usefulness of BPC during local ablation therapies in patients with HCC. We evaluated 283 HCC nodules that underwent local ablation therapy. These nodules were categorized into high- or low-risk locations on the basis of their proximity to large vessels, adjacent extrahepatic organs, or poor visibility under ultrasound (US) guidance. The technical success rates, procedure time, and prognosis were evaluated. In this study, 176 (62%) nodules were classified in the high-risk location group. The high-risk location group was treated with techniques such as BPC, artificial pleural fluid, artificial ascites, fusion imaging, and contrast-enhanced US more frequently than the low-risk location group. The technical success rates were 96% and 95% for the high- and low-risk location groups, respectively. Within the high-risk location group, those without BPC had a lower success rate than those with BPC (91% vs. 99%, p = 0.015). Notably, BPC emerged as the sole contributing factor to the technical success rate in the high-risk location group (OR = 10, 95% CI 1.2-86, p = 0.034). In contrast, no differences were found in the procedure time, local tumor progression rates, intrahepatic distant recurrence rates, and overall survival between the groups with and without BPC in the high-risk location group. In conclusion, BPC during local ablation therapy in patients with HCC in high-risk locations was safe and efficient. The body position should be adjusted for HCC in high-risk locations to maintain good US visibility and ensure a safe puncture route in patients undergoing local ablation therapies.

Three-dimensional ultrasound fusion imaging in precise needle placement for thermal ablation of hepatocellular carcinoma

Purpose To investigate the value of three-dimensional ultrasound fusion imaging (3DUS FI) technique for guiding needle placement in hepatocellular carcinoma (HCC) thermal ablation. Methods A total of 57 patients with 60 HCCs with 3DUS FI-guided thermal ablation were retrospectively included in the study. 3DUS volume data of liver were acquired preoperatively by freehand scanning with the tumor and predetermined 5 mm ablative margin automatically segmented. Plan of needle placement was made through a predetermined simulated ablation zone to ensure a 5 mm ablative margin with the coverage rate toward tumor and ablative margin. With real-time ultrasound and 3DUS fusion imaging, ablation needles were placed according to the plan. After ablation, the ablative margin was immediately evaluated by contrast-enhanced ultrasound and 3DUS fusion imaging. The rate of adequate ablative margin, complete response (CR), local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) was evaluated. Results According to postoperative contrast-enhanced CT or MR imaging, the complete response rate was 100% (60/60), and 83% of tumors (30/36) achieved adequate ablative margin (>5 mm) three-dimensionally. During the follow-up period of 6.0-42.6 months, LTP occurred in 5 lesions, with 1- and 2-year LTP rates being 7.0% and 9.4%. The 1- and 2-year DFS rates were 76.1% and 65.6%, and 1- and 2-year OS rates were 98.1% and 94.0%. No major complications or ablation-related deaths were observed in any patients. Conclusions Three-dimensional ultrasound fusion imaging technique may improve the needle placement of thermal ablation for HCC and reduce the rate of LTP.

Ablative margin quantification using deformable versus rigid image registration in colorectal liver metastasis thermal ablation: a retrospective single-center study.

To investigate the correlation of minimal ablative margin (MAM) quantification using biomechanical deformable (DIR) versus intensity-based rigid image registration (RIR) with local outcomes following colorectal liver metastasis (CLM) thermal ablation. This retrospective single-institution study included consecutive patients undergoing thermal ablation between May 2016 and October 2021. Patients who did not have intraprocedural pre- and post-ablation contrast-enhanced CT images for MAM quantification or follow-up period less than 1year without residual tumor or local tumor progression (LTP) were excluded. DIR and RIR methods were used to quantify the MAM. The registration accuracy was compared using Dice similarity coefficient (DSC). Area under the receiver operating characteristic curve (AUC) was used to test MAM in predicting local tumor outcomes. A total of 72 patients (mean age 57; 44 men) with 139 tumors (mean diameter 1.5cm ± 0.8 (SD)) were included. During a median follow-up of 29.4months, there was one residual unablated tumor and the LTP rate was 17% (24/138). The ranges of DSC were 0.96-0.98 and 0.67-0.98 for DIR and RIR, respectively (p < 0.001). When using DIR, 27 (19%) tumors were partially or totally registered outside the liver, compared to 46 (33%) with RIR. Using DIR versus RIR, the corresponding median MAM was 4.7mm versus 4.0mm, respectively (p = 0.5). The AUC in predicting residual tumor and 1-year LTP for DIR versus RIR was 0.89 versus 0.72, respectively (p < 0.001). Ablative margin quantified on intra-procedural CT imaging using DIR method outperformed RIR for predicting local outcomes of CLM thermal ablation. The study supports the role of biomechanical deformable image registration as the preferred image registration method over rigid image registration for quantifying minimal ablative margins using intraprocedural contrast-enhanced CT images. • Accurate and reproducible image registration is a prerequisite for clinical application of image-based ablation confirmation methods. • When compared to intensity-based rigid image registration, biomechanical deformable image registration for minimal ablative margin quantification was more accurate for liver registration using intraprocedural contrast-enhanced CT images. • Biomechanical deformable image registration outperformed intensity-based rigid image registration for predicting local tumor outcomes following colorectal liver metastasis thermal ablation.

Percutaneous microwave ablation versus sclerotherapy for large hepatic hemangioma: a multi-center cohort study

Objective The study aimed to compare the effectiveness and safety of ultrasound-guided microwave ablation (MWA) and percutaneous sclerotherapy (PS) for the treatment of large hepatic hemangioma (LHH). Methods This retrospective study included 96 patients who underwent MWA (n = 54) and PS (n = 42) as first-line treatment for LHH in three tertiary hospitals from January 2016 to December 2021. Primary outcomes were technique efficacy rate (volume reduction rate [VRR] > 50% at 12 months), symptom relief rate at 12 months and local tumor progression (LTP). Secondary outcomes included procedure time, major complications, treatment sessions, cost and one-, two-, three-year VRR. Results During a median follow-up of 36 months, the MWA group showed a higher technique efficacy rate (100% vs. 90.4%, p = .018) and symptom relief rate (100% vs. 80%, p = .123) than the PS group. The MWA group had fewer treatment sessions, higher one-, two- and three-year VRR, lower LTP rate (all p < .05), longer procedure time and higher treatment costs than the PS group (both p < .001). MWA shared a comparable major complications rate (1.8% vs. 2.4%, p = .432) with PS. After multivariate analysis, the lesion’s heterogeneity and maximum diameter >8.1 cm were independent risk factors for LTP (all p < .05). In the PS group, lesions with a cumulative dose of bleomycin > 0.115 mg/cm3 had a lower risk of LTP (p = .006). Conclusions Both MWA and PS treatments for large hepatic hemangioma are safe and effective, with MWA being superior in terms of efficacy.

No-Touch Radiofrequency Ablation Using Twin Cooled Wet Electrodes for Recurrent Hepatocellular Carcinoma Following Locoregional Treatments.

To evaluate the therapeutic outcomes of no-touch radiofrequency ablation (NT-RFA) using twin cooled wet (TCW) electrodes in patients experiencing recurrent hepatocellular carcinoma (HCC) after undergoing locoregional treatments. We conducted a prospective, single-arm study of NT-RFA involving 102 patients, with a total of 112 recurrent HCCs (each ≤ 3 cm). NT-RFA with TCW electrodes was implemented under the guidance of ultrasonography (US)-MR/CT fusion imaging. If NT-RFA application proved technically challenging, conversion to conventional tumor puncture RFA was permitted. The primary metric for evaluation was the mid-term cumulative incidence of local tumor progression (LTP) observed post-RFA. Cumulative LTP rates were estimated using the Kaplan-Meier method. Multivariable Cox proportional hazard regression was used to explore factors associated with LTP. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat (ITT; including all patients) and per-protocol (PP; including patients not requiring conversion to conventional RFA alone) analyses were performed. Conversion from NT-RFA to conventional RFA was necessary for 24 (21.4%) out of 112 tumors. Successful treatment was noted in 111 (99.1%) out of them. No major complications were reported among the patients. According to ITT analysis, the estimated cumulative incidences of LTP were 1.9%, 6.0%, and 6.0% at 1, 2, and 3 years post-RFA, respectively. In PP analysis, the cumulative incidence of LTP was 0.0%, 1.3%, and 1.3% at 1, 2, and 3 years, respectively. The number of previous locoregional HCC treatments (adjusted hazard ratio [aHR], 1.265 per 1 treatment increase; P = 0.004), total bilirubin (aHR, 7.477 per 1 mg/dL increase; P = 0.012), and safety margin ≤ 5 mm (aHR, 9.029; P = 0.016) were independently associated with LTP in ITT analysis. NT-RFA using TCW electrodes is a safe and effective treatment for recurrent HCC, with 6.0% (ITT analysis) and 1.3% (PP analysis) cumulative incidence of LTP at 2 and 3-year follow-ups.

Clinical Impact of a Protocol Involving Cone-Beam CT (CBCT), Fusion Imaging and Ablation Volume Prediction in Percutaneous Image-Guided Microwave Ablation in Patients with Hepatocellular Carcinoma Unsuitable for Standard Ultrasound (US) Guidance.

to evaluate the clinical impact of a protocol for the image-guided percutaneous microwave ablation (MWA) of hepatocellular carcinoma (HCC) that includes cone-beam computed tomography (CBCT), fusion imaging and ablation volume prediction in patients with hepatocellular carcinoma unsuitable for standard ultrasound (US) guidance. this study included all patients with HCC treated with MWA between January 2021 and June 2022 in a tertiary institution. Patients were divided into two groups: Group A, treated following the protocol, and Group B, treated with standard ultrasound (US) guidance. Follow-up images were reviewed to assess residual disease (RD), local tumor progression (LTP) and intrahepatic distant recurrence (IDR). Ablation response at 1 month was also evaluated according to mRECIST. Baseline variables and outcomes were compared between the groups. For 1-month RD, propensity score weighting (PSW) was performed. 80 consecutive patients with 101 HCCs treated with MWA were divided into two groups. Group A had 41 HCCs in 37 patients, and Group B had 60 HCCs in 43 patients. Among all baseline variables, the groups differed regarding their age (mean of 72 years in Group A and 64 years in Group B, respectively), new vs. residual tumor rates (48% Group A vs. 25% Group B, p < 0.05) and number of subcapsular tumors (56.7% Group B vs. 31.7% Group A, p < 0.05) and perivascular tumors (51.7% Group B vs. 17.1% Group A, p < 0.05). The protocol led to repositioning the antenna in 49% of cases. There was a significant difference in 1-month local response between the groups measured as the RD rate and mRECIST outcomes. LTP rates at 3 and 6 months, and IDR rates at 1, 3 and 6 months, showed no significant differences. Among all variables, logistic regression after PSW demonstrated a protective effect of the protocol against 1-month RD. The use of CBCT, fusion imaging and ablation volume prediction during percutaneous MWA of HCCs provided a better 1-month tumor local control. Further studies with a larger population and longer follow-up are needed.