Viable hepatocellular carcinoma around retained iodized oil after transarterial chemoembolization: radiofrequency ablation of viable tumor plus retained iodized oil versus viable tumor alone

Development and evaluation of polyacrylamide microspheres loaded with phloretin and tantalum for transcatheter arterial embolization

Transcatheter arterial embolization is an effective treatment for liver cancer. However, the development of novel embolic agents remains a challenge. In this study, we evaluated polyacrylic acid microspheres loaded with phloretin and tantalum as potential embolic agents for liver cancer treatment. Microspheres were synthesised via emulsion polymerisation and characterised in terms of size, shape, and drug-loading efficiency. Nanosized tantalum powder (0 to 15%) was added to the microspheres as an X-ray blocking agent. The maximum drug-loading capacity of the microspheres was approximately 20 mg g-1. The phloretin-loaded microspheres showed a sustained drug release profile in vitro. The microspheres were also evaluated for their in vivo anticancer efficacy in a rabbit VX2 liver tumour model. In conclusion, polyacrylic acid microspheres loaded with phloretin and tantalum have great potential as novel embolic agents for transcatheter arterial embolization for liver cancer treatment.

Factors associated with increased risk of peritoneal seeding after radiofrequency ablation for hepatocellular carcinoma

PURPOSE

To evaluate the incidence, risk factors, and prognosis associated with peritoneal seeding after percutaneous radiofrequency ablation (RFA) for HCC, focusing on viable tumors after previous locoregional treatment, including TACE and RFA.

METHODS

Exactly 290 patients (mean age, 67.9 years ± 9.74; 223 men) with 383 HCCs (mean size, 15.9 mm ± 5.49) who underwent RFA between June 2012 and December 2019 were included in this retrospective study. Among them, 158 had history of previous treatment (mean number, 1.3 ± 1.8) with 109 viable HCCs. Cumulative seeding after RFA was estimated using the Kaplan-Meier method. Independent factors affecting seeding were investigated using multivariable Cox proportional hazards regression analysis.

RESULTS

Median follow-up was 1175 days (range: 28-4116). Seeding incidence was 4.1 (12/290) and 4.7% (17/383) per patient and tumor, respectively. The median time interval between RFA and detection of seeding was 785 days (range: 81-1961). Independent risk factors for seeding included subcapsular tumor location (hazard ratio [HR] 4.2; 95% confidence interval [CI] 1.4, 13.0; p = 0.012) and RFA for viable HCC after previous locoregional treatment (HR 4.5; 95% CI 1.7, 12.3; p = 0.003). Subgroup analysis for viable tumors, revealed no significant difference in cumulative seeding rates between the TACE and RFA groups (p = 0.078). Cumulative overall survival rates differed significantly between patients with and without seeding metastases (p < 0.001).

CONCLUSION

Peritoneal seeding after RFA is a rare, delayed complication. Subcapsular-located and viable HCC after previous locoregional treatment are potential risk factors for seeding. Seeding metastases could affect the prognosis of patients who cannot receive local therapy.

Computed tomography-guided radiofrequency ablation of the retained iodized oil after simultaneous combination with transarterial embolization in small recurrent or residual hepatocellular carcinoma

Objective

To assess the clinical efficacy and safety of transarterial embolization (TAE) in simultaneous combination with computed tomography (CT)-guided radiofrequency ablation (RFA) for recurrent or residual hepatocellular carcinoma (HCC), and to determine the risk factors influencing local tumor progression following this procedure.

Methods

One hundred eighteen patients with recurrent or residual HCC (tumor size, 10-30 ​mm) underwent RFA. During the 19-month follow-up, 59 patients received RFA only (RFA group), and the remaining 59 received RFA immediately after TAE (TAE ​+ ​RFA group). All patients were followed up to observe the short-term therapeutic effects and complications. The cumulative local tumor progression rates in both groups were calculated using unpaired Student's t tests and the Kaplan-Meier method.

Results

The rate of major complications was 5.08% in the TAE ​+ ​RFA group and 3.39% in the RFA group. The overall response rate was 96.61% in the TAE ​+ ​RFA group and 79.66% in the RFA group (P ​= ​0.008). The disease control rate was significantly higher in the TAE ​+ ​RFA group than in the RFA group (94.92% vs. 79.66%, P ​= ​0.024). The median time to local tumor progression was 4.8 months in the RFA group and 9.6 months in the TAE ​+ ​RFA group. The cumulative local tumor progression rate at 1 year was 10.60% in the RFA group and 23.60% in the TAE ​+ ​RFA group (P ​= ​0.016).

Conclusion

TAE in simultaneous combination with CT-guided RFA was effective and safe against recurrent or residual HCC. Local tumor progression can be minimized by the complete ablation of targeted iodized oil deposits after simultaneous TAE.

Whole tumor ablation of locally recurred hepatocellular carcinoma including retained iodized oil after transarterial chemoembolization improves progression-free survival

OBJECTIVES

To evaluate and compare clinical outcomes of two different radiofrequency ablation (RFA) methods for locally recurred hepatocellular carcinoma (LrHCC) after locoregional treatment.

METHODS

Our institutional review board approved this study with a waiver of informed consent. A total of 313 patients previously treated with transarterial chemoembolization (TACE) (n = 167) and RFA (n = 146) with a single LrHCC ≤ 3 cm was included from five tertiary referral hospitals. RFA was done for LrHCCs using either viable tumor alone ablation (VTA) method (VTA: n = 61 in the TACE group and n = 127 in the RFA group) or whole tumor ablation (WTA) method which includes both viable tumor and retained iodized oil or previously ablated zone (WTA: n = 106 in the TACE group and n = 19 in the RFA group). Local tumor progression (LTP)-free survival as well as progression-free survival (PFS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated using the Cox proportional hazards regression model.

RESULTS

In 167 patients with LrHCC who underwent TACE, the 5-year LTP-free survival after RFA was significantly higher with the VTA method than with the WTA method (26.9% vs. 87.8%; p < 0.001; hazard ratio (HR) = 8.53 [4.16-17.5]). The estimated 5-year PFS after RFA for LrHCC after TACE using the VTA method was 5.7%, which was significantly lower than that with the WTA method (26.4%) (p = 0.014; HR = 1.62 [1.10-2.38]). However, in 146 patients with LrHCC after initial RFA, there were no significant differences in cumulative incidence of LTP (p = 0.514) or PFS (p = 0.905) after RFA between the two ablation methods.

CONCLUSIONS

For RFA of LrHCC after TACE, the WTA method including both viable tumor and retained iodized oil could significantly lower LTP and improve PFS than VTA.

KEY POINTS

• Whole tumor ablation (WTA) could provide significantly better local tumor control for locally recurred HCC (LrHCC) after TACE than viable tumor alone ablation (VTA). • WTA for LrHCC after TACE could also provide significantly better progression-free survival than VTA. • Regarding LrHCC after RFA, VTA would provide a comparable clinical outcome to WTA.

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.

Liver Ablation: Best Practice

Tumor ablation in the liver has evolved to become a well-accepted tool in the management of increasing complex oncologic patients. At present, percutaneous ablation is considered first-line therapy for very early and early hepatocellular carcinoma and second-line therapy for colorectal carcinoma liver metastasis. Because thermal ablation is a treatment option for other primary and secondary liver tumors, an understanding of the underlying tumor biology is important when weighing the potential benefits of ablation. This article reviews ablation modalities, indications, patient selection, and imaging surveillance, and emphasizes technique-specific considerations for the performance of percutaneous ablation.