Analysis of therapeutic effect and influencing factors of radiofrequency ablation for colorectal cancer liver metastases / 中华放射学杂志

Objective:To explore the efficacy and influencing factors of radiofrequency ablation (RFA) in the treatment of colorectal cancer liver metastases (CRLM).Methods:The clinical and imaging data of 281 patients (477 intrahepatic metastatic tumors) who received percutaneous RFA treatment in Sir Run Run Shaw Hospital, Zhejiang University School of Medicine from December 2009 to December 2020 were retrospectively analyzed. Factors that may affect the efficacy of RFA were recorded, including carcinoembryonic antigen (CEA), differentiation, extrahepatic metastasis, tumor location and size, complications and other information. Patients were followed up through hospital admissions, telephone, etc. The primary endpoints were overall survival (OS) and local tumor progression-free survival (LTPFS). Univariate and multivariate logistic regression models were used to identify predictors of residual tumor. Univariate and multivariate Cox proportional hazards regression were used to identify the influencing factors of LTPFS and OS. The median LTPFS and OS were estimated by the Kaplan-Meier curve and compared by the log-rank test.Results:After RFA, 68 (14.3%) tumor residues were observed. Multivariate logistic regression showed that the risk factors for residual tumor were size ≥20 mm, high-risk and perivascular location, and minimal ablative margin<5 mm. During the follow-up period, the main complication rate was 4.3% (12/281) and the fatality rate was 31.3% (88/281). At the same time, local tumor progression was found in 167 (35.0%) lesions post-RFA. The median time of LTPFS and OS estimated by the Kaplan Meier method were 35.0 (95%CI 26.53-43.48) and 44.0 (95%CI 29.70-58.30) months, respectively. The cumulative proportion of LTPFS and OS were 37.2% and 40.4% respectively in the 5th year. Multivariate Cox proportional hazard regression showed that CEA≥30 ng/ml, tumor size ≥20 mm, and minimal ablative margin<5 mm were risk factors for LTPFS; extrahepatic metastasis, tumor burden>30 mm, and lesion with minimal ablative margin<5 mm were independent risk factors for OS; re-intervention was an independent protective factor for OS.Conclusions:Adequate ablative margin and less tumor burden were beneficial to local tumor control and long-term survival of patients in the RFA treatment; the existence of extrahepatic metastasis was an important risk factor for OS, and re-interventional therapy was beneficial to extend OS.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration

OBJECTIVE: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. MATERIALS AND METHODS: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. RESULTS: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). CONCLUSION: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Computed Tomographic-Guided Radiofrequency Ablation of Recurrent or Residual Hepatocellular Carcinomas around Retained Iodized Oil after Transarterial Chemoembolization

OBJECTIVE: To assess the clinical efficacy, safety, and risk factors influencing local tumor progression, following CT-guided radiofrequency ablation (RFA) of recurrent or residual hepatocellular carcinoma (HCC), around iodized oil retention. MATERIALS AND METHODS: Sixty-four patients (M : F = 51 : 13, 65.0 +/- 8.2 years old) with recurrent or residual HCC (75 index tumors, size = 14.0 +/- 4.6 mm) had been treated by CT-guided RFA, using retained iodized oil as markers for targeting. The technical success, technique effectiveness rate and complications of RFA were then assessed. On pre-ablative and immediate follow-up CT after RFA, we evaluated the size of enhancing index tumors and iodized oil retention, presence of abutting vessels, completeness of ablation of iodized oil retention, and the presence of ablative margins greater than 5 mm. Also, the time interval between transarterial chemoembolization and RFA was assessed. The cumulative local tumor progression rate was calculated using the Kaplan-Meier method, and the Cox proportional hazards model was adopted, to clarify the independent factors affecting local tumor progression. RESULTS: The technical success and technique effectiveness rate was 100% and 98.7%, respectively. Major complications were observed in 5.6%. The cumulative rates of local tumor progression at 1 and 2 years were 17.5% and 37.5%, respectively. In multivariate analyses, partial ablation of the targeted iodized oil retention was the sole independent predictor of a higher local tumor progression rate. CONCLUSION: CT-guided RFA of HCC around iodized oil retention was effective and safe. Local tumor progression can be minimized by complete ablation of not only index tumors, but targeted iodized oil deposits as well.

Consolidative repeat radiofrequency ablation for alpha-fetoprotein negative hepatocellular carcinoma: does it have a role in local tumor control / 中华肝胆外科杂志

Objective To retrospectively evaluate the role of consolidative repeat radiofrequency ablation (CRRFA) based on safety margin (SM) analyses in local tumor control for alpha-fetoprotein (AFP) negative hepatocellular carcinoma (HCC) patients who had been shown to have radiological complete ablation (CA) with radiofrequency ablation (RFA). Methods From July 2002 to July 2009,152 AFP negative HCC patients who were shown to have radiological CA with RFA therapy were retrospectively analyzed. Among them, 110 patients had a SM of less than 1 cm and the other 42 patients had a SM of 1cm or more. Among 110 patients with SM less than 1 cm, fifty nine patients accepted CRRFA within 6 months after the first RFA and 51 did not. From these patients, a narrow SM-CRRFA group (n=41) and a narrow SM-single RFA group (n=37) were enrolled respectively. The wide SM-single RFA group (n= 30) was enrolled from the 42 patients with a SM of 1 cm or more.The LTP (local tumor progression)-free survival rate of the 3 groups were compared with a log-rank test. Results One-, two-, three-, four-, and five-year LTP-free survival rates respectively were 97. 1%, 90.9%, 69.6%, 47.2%, and 33. 0% in the narrow SM-CRRFA patients. 85.9%, 66. 5%,43.5%, 15.8%, and 0. 0%, in the narrow SM-single RFA patients, and were 92.7%, 83.7%,59.3%, 36. 9%, and 9.2% in the wide SM-single RFA patients. There were statistically significant differences (χ2 = 14. 789, P= 0. 001) between the groups. Conclusions An ablation zone with an SM of 1 cm or greater was the most important factor for local control of AFP negative HCC ranging from 3 to 5 cm in diameter. For these patients with a SM of less than 1 cm, CRRFA improved the overall local control outcomes.