Outcomes after primary and repeat thermal ablation of hepatocellular carcinoma with or without liver transplantation

Safety of local thermal ablation in hepatocellular carcinoma patients with cirrhosis and severe thrombocytopenia

Generally, invasive treatment is contraindication for patients with severe thrombocytopenia, because it may increase risk of bleeding. However, many early hepatocellular carcinoma (HCC) patients with cirrhosis have platelet counts (PC) less than 50 × 109/L due to hypersplenism. These patients are often accompanied by hepatic insufficiency, which makes hepatectomy impossible, and local thermal ablation (LTA) has become a major treatment. The aim of our study is to investigate the correlation between severe thrombocytopenia and bleeding after LTA in HCC patients with cirrhosis, and evaluate risk factors of bleeding. 473 patients with cirrhosis who underwent LTA for HCC from 2016 to 2020 were enrolled, and 709 ablations were performed in total. Based on preoperative PC, cases were divided into three groups, namely, group A (PC > 50 × 109/L), group B (30 × 109/L < PC ≤ 50 × 109/L) and group C (PC ≤ 30 × 109/L). The incidence of bleeding after LTA was compared among the three groups. Logistic regression was used to explore the risk factors for bleeding after ablation. The overall incidence of bleeding complications was 4.4%, and no significant difference was observed between group A, B, and C (3.9% vs. 6.4% vs. 3.3%, P = 0.410). In multivariate analysis, tumor diameter (OR = 2.657 per 1 cm, P < 0.001), and multiple lesions (≥ 3) (OR = 3.723, P = 0.006) were found to be independent predictors of bleeding after LTA. In small HCC patients with cirrhosis and hypersplenism, the PC range 30-50 × 109/L will not increase the risk of bleeding after LTA. Tumor diameter and number of lesions are independent predictors for bleeding after LTA in HCC patients.

Outcomes and Complications of Image-Guided Percutaneous Tumour Ablation for Hepatocellular Carcinoma at the Irish National Liver Transplant Centre

Background: Image-guided tumour ablation is a minimally invasive treatment for early stage hepatocellular carcinoma (HCC). Our study reviews the complications and long term outcomes in patients treated at a tertiary referral centre. Methods: Retrospective study. All patients with HCC who underwent microwave ablation (MWA) or radiofrequency ablation (RFA) from 1st January 2014 to 31st December 2022 were identified. Treatment response of target lesion, complications, and survival were recorded. Results: One hundred seventy ablations were performed in 118 patients; 70% MWA, 30% RFA. Median radiological follow-up 21 months (range 3-107). Follow-up imaging was reported using LI-RADS and mRECIST. At first follow-up imaging, 94 patients had complete response (primary efficacy rate 80.3%) while 19.7% (n = 23) had residual disease. Fifteen of these had repeat ablation; 10 had complete response (secondary efficacy rate 85.6%). By end of study duration, 70.5% (n = 79) achieved sustained local complete response from single ablation without documented recurrence. 14.3% (n = 16) required more than one ablation of target lesion. Overall, 84.8% (n = 95) demonstrated long term local complete response to ablation. Complication occurred in 5.9% (n = 10); 40.0% Grade I, 40.0% Grade II, 10.0% Grade III, 10.0% Grade IV as per the CIRSE Classification. 1-, 3-, and 5-year overall survival (OS) rate was 97%, 68%, and 61% respectively. Mean OS was 5.3 years (median 4.7). No difference in OS (P = .7) or local progression free survival (P = .5) between patients treated with MWA versus RFA. Conclusion: This study demonstrates excellent long-term response to TA, with acceptable complication profile. No difference in survival between RFA versus MWA.

Machine learning-based radiomic analysis and growth visualization for ablation site recurrence diagnosis in follow-up CT

OBJECTIVES

Detecting ablation site recurrence (ASR) after thermal ablation remains a challenge for radiologists due to the similarity between tumor recurrence and post-ablative changes. Radiomic analysis and machine learning methods may show additional value in addressing this challenge. The present study primarily sought to determine the efficacy of radiomic analysis in detecting ASR on follow-up computed tomography (CT) scans. The second aim was to develop a visualization tool capable of emphasizing regions of ASR between follow-up scans in individual patients.

MATERIALS AND METHODS

Lasso regression and Extreme Gradient Boosting (XGBoost) classifiers were employed for modeling radiomic features extracted from regions of interest delineated by two radiologists. A leave-one-out test (LOOT) was utilized for performance evaluation. A visualization method, creating difference heatmaps (diff-maps) between two follow-up scans, was developed to emphasize regions of growth and thereby highlighting potential ASR.

RESULTS

A total of 55 patients, including 20 with and 35 without ASR, were included in the radiomic analysis. The best performing model was achieved by Lasso regression tested with the LOOT approach, reaching an area under the curve (AUC) of 0.97 and an accuracy of 92.73%. The XGBoost classifier demonstrated better performance when trained with all extracted radiomic features than without feature selection, achieving an AUC of 0.93 and an accuracy of 89.09%. The diff-maps correctly highlighted post-ablative liver tumor recurrence in all patients.

CONCLUSIONS

Machine learning-based radiomic analysis and growth visualization proved effective in detecting ablation site recurrence on follow-up CT scans.

A dual-tracer approach using [11C]CH and [18F]FDG in HCC clinical decision making

BACKGROUND

Early detection of recurrent or progressive HCC remains the strongest prognostic factor for survival. Dual tracer PET/CT imaging with [11C]CH and [18F]FDG can further increase detection rates as both tracers entail different metabolic pathways involved in HCC development. We investigated dual-tracer PET/CT in clinical decision making in patients suspected of recurrent or progressive HCC. All HCC patients who underwent both [11C]CH and [18F]FDG PET/CT in our institute from February 2018 to December 2021 were included. Both tracer PET/CT were within 4 weeks of each other with at least 6-month follow-up. Patients underwent dual tracer PET/CT because of unexplained and suspicious CT/MRI or sudden rise of serum tumour markers. A detected lesion was considered critical when the finding had prognostic consequences leading to treatment changes.

RESULTS

Nineteen patients who underwent [11C]CH and [18F]FDG PET/CT were included of which all but six patients were previously treated for HCC. Dual-tracer critical finding detection rate was 95%, with [18F]FDG 68%, and [11C]CH 84%. Intrahepatic HCC recurrence finding rate was 65% for both tracers. [18F]FDG found more ablation site recurrences (4/5) compared to [11C]CH (2/5). Only [11C]CH found two needle tract metastases. Both tracers found 75% of the positive lymph nodes. Two new primary tumours were found, one by [18F]FDG and both by [11C]CH.

CONCLUSIONS

Our study favours a dual-tracer approach in HCC staging in high-risk patients or when conventional imaging is non-conclusive.

Risk of Treatment Failure and Death after Ablation in Hepatocellular Carcinoma Patients-A Multiparametric Prediction

BACKGROUND

Ablation is a first-line treatment for Barcelona Clinic Liver Cancer (BCLC)-0/A hepatocellular carcinoma (HCC). However, there are scarce data about patients' outcomes after recurrence. The present study evaluates the impact of patient and tumor characteristics at baseline and at recurrence on the Clinical Decision-Making process.

METHODS

We evaluated BCLC-0/A patients treated with percutaneous ablation from January 2010 to November 2018. Clinical and radiological data such as age, tumor location at ablation, pattern of recurrence/progression, and comorbidities during follow-up were registered. Tumor location was divided into 'suboptimal' vs. 'optimal' locations for ablation. The Clinical Decision-Making was based on tumor burden, liver dysfunction, or comorbidities. The statistical analysis included the time-to-recurrence/progression, censoring at time of death, date of last follow-up or liver transplantation, and time-to-event was estimated by the Kaplan-Meier method and Cox regression models to evaluate the risk of an event of death and change of treatment strategy.

RESULTS

A total of 225 patients [39.1% BCLC-0 and 60.9% BCLC-A] were included, 190 had unifocal HCC and 82.6% were ≤3 cm. The complete response rate and median overall survival were 96% and 60.7 months. The HCC nodules number (Hazard Ratio-HR 3.1), Child-Pugh (HR 2.4), and Albumin-Bilirubin score (HR 3.2) were associated with increased risk of death during follow-up. HCC in 'suboptimal location' presented a shorter time to recurrence. When comorbidities prevented further loco-regional or systemic treatment, the risk of death was significantly increased (HR 2.0, p = 0.0369) in comparison to those who received treatment.

CONCLUSIONS

These results expose the impact of non-liver comorbidities when considering treatment for recurrence after ablation in the real-world setting and in research trials. Ultimately, we identified an orphan population for which effective interventions are needed.

Virtual Treatment Zone From Cone Beam CT Commonly Alters Treatment Plan and Identifies Tumor at Risk for Under-Treatment in US or US Fusion-Guided Microwave Ablation of Liver Tumors

Tumor ablation is included in several major cancer therapy guidelines. One technical challenge of percutaneous ablation is targeting and verification of complete treatment, which is prone to operator variabilities and human imperfections and are directly related to successful outcomes, risk for residual unablated tumor and local progression. The use of "Prediction Ablation Volume Software" may help the operating Interventional Radiologist to better plan, deliver, and verify before the ablation, via virtual treatment zones fused to target tumor. Fused and superimposed images provide 3-dimensional information from different timepoints, just when that information is most useful. The aim of this study is to evaluate the technical success and efficacy of an ablation treatment flowchart provided by a cone beam computed tomography (CBCT) "Prediction Ablation Volume Software." This is a single-center retrospective study. From April 2021 to January 2022, 29 nonconsecutive evaluable patients with 32 lesions underwent liver ablation with Prediction Ablation Volume Software. Each patient was discussed in a multidisciplinary tumor board and underwent an enhanced computed tomography or magnetic resonance imaging approximately 1 month before the procedure, as well as ∼1 month after. Technical success was defined as treatment of the tumor according to the protocol, covered completely by the Prediction Ablation Volume. Technical efficacy was defined as assessment of complete ablation of the target tumor at imaging follow up (∼1 month). Technical success, technical efficacy, and procedural factors were studied. Technical success was achieved in 30 of 32 liver lesions (94%), measuring 20 mm mean maximum diameter. The antenna was repositioned in 16 of 30 (53%) evaluable target lesions. Residual tumor was detected at 1 month imaging follow up in only 4 of 30 (13%) of the treated lesion. Technical efficacy was of 87% in this retrospective description of our process. The implementation of a CBCT Prediction Ablation Volume Software and flowchart for the treatment of liver malignancies altered the procedure, and demonstrated high technical success and efficacy. Such tools are potentially useful for procedural prediction and verification of ablation.

Comparison of Two 2.45 GHz Microwave Ablation Devices with Respect to Ablation Zone Volume in Relation to Applied Energy in Patients with Malignant Liver Tumours

Purpose: (i) to compare two 2.45 GHz MWA devices with respect to AZV in relation to the applied energy after MWA in patients with hepatocellular carcinoma (HCC) or colorectal liver metastasis (CRLM) and (ii) to identify potential confounders for this relationship. Methods: In total, 102 tumours, 65 CRLM and 37 HCC were included in this retrospective analysis. Tumours were treated with Emprint (n = 71) or Neuwave (n = 31) MWA devices. Ablation treatment setting were recorded and applied energy was calculated. AZV and tumour volumes were segmented on the contrast-enhanced CT scans obtained 1 week after treatment. The AZV to applied energy R(AZV:E) ratios were calculated for each tumour treatment and compared between both MWA devices and tumour types. Results: R(AZV:E)EMPRINT was 0.41 and R(AZV:E)NEUWAVE was 0.81, p < 0.001. Moderate correlation between AZV and applied energy was found for Emprint (r = 0.57, R2 = 0.32, p < 0.001) and strong correlation was found for Neuwave (r = 0.78, R2 = 0.61, p < 0.001). R(AZV:E)CRLM was 0.45 and R(AZV:E)HCC was 0.52, p = 0.270. Conclusion: This study confirms the unpredictability of AZVs based on the applied output energy for HCC and CRLM. No significant differences in R(AZV:E) were observed between CRLM and HCC. Significantly lower R(AZV:E) was found for Emprint devices compared to Neuwave; however, reflected energy due to cable and antenna design remains unclear and might contribute to these differences.