Computed tomography and histopathological findings after embolization with inherently radiopaque 40μm-microspheres, standard 40μm-microspheres and iodized oil in a porcine liver model

Safety, Efficacy and Distribution of Doxorubicin Loaded Radiopaque Beads in Chemoembolization in Intermediate Stage Hepatocellular Carcinoma (HCC) with Correlation with Local Response

PURPOSE

The primary objectives of this study were to evaluate safety, and efficacy of Transarterial Chemoembolization (TACE) using doxorubicin-loaded radiopaque microspheres (DC Bead LUMI™) for the treatment of early and intermediate stage Hepatocellular Carcinoma (HCC) not amenable for curative treatments. Distribution of the microspheres was correlated with results post embolization.

MATERIALS AND METHODS

This was a prospective, single arm, open label study. The primary outcome measures were distribution of the radiopaque microspheres as showed by computerized tomography (CT) and local response measured by modified Response Evaluation Criteria (mRECIST) after Magnetic Resonance Imaging (MRI). Secondary measures were Time to Progression (TTP) and Overall Survival (OS).

RESULTS

Fifty patients were enrolled over 36 months. Median age was 69.0 years; mean sum of target lesions diameters was 78.6 ± 36.8 mm. There were no Grade 4 or 5 adverse events (AEs). At 6 months Complete Response (CR) (18%), Partial Response (PR) (62%), Objective Response OR (80%) and Stable Disease (SD) (20%) were recorded. Before embolization, Diffusion Weighted Imaging (DWI) showed high signal (restricted diffusion). Post procedure, patients with dense deposition (< 5 mm distance of microsphere aggregations) showed 100% absence of enhancement and no restriction in 30.6%. Median TTP was 8.3 months. TTP for patients with CR was 13.3 months and 7.2 and 5.6 for PR and SD, respectively. At 6 and 36 months, survival was 94% and 34%, respectively.

CONCLUSION

DC Bead LUMI™ is well tolerated and effective in early and intermediate stage HCC with maximal necrosis obtained in dense deposition in the target.

Percutaneous Irreversible Electroporation for Treatment of Small Hepatocellular Carcinoma Invisible on Unenhanced CT: A Novel Combined Strategy with Prior Transarterial Tumor Marking

INTRODUCTION

To explore the feasibility, safety, and efficiency of ethiodized oil tumor marking combined with irreversible electroporation (IRE) for small hepatocellular carcinomas (HCCs) that were invisible on unenhanced computed tomography (CT).

METHODS

A retrospective analysis of the institutional database was performed from January 2018 to September 2018. Patients undergoing ethiodized oil tumor marking to improve target-HCC visualization in subsequent CT-guided IRE were retrieved. Target-HCC visualization after marking was assessed, and the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNR) were compared between pre-marking and post-marking CT images using the paired t-test. Standard IRE reports, adverse events, therapeutic endpoints, and survival were summarized and assessed.

RESULTS

Nine patients with 11 target-HCCs (11.1-18.8 mm) were included. After marking, all target-HCCs demonstrated complete visualization in post-marking CT, which were invisible in pre-marking CT. Quantitatively, the SNR of the target-HCCs significantly increased after marking (11.07 ± 4.23 vs. 3.36 ± 1.79, p = 0.006), as did the CNR (4.32 ± 3.31 vs. 0.43 ± 0.28, p = 0.023). In sequential IRE procedures, the average current was 30.1 ± 5.3 A, and both the delta ampere and percentage were positive with the mean values of 5.8 ± 2.1 A and 23.8 ± 6.3%, respectively. All procedures were technically successful without any adverse events. In the follow-up, no residual unablated tumor (endpoint-1) was observed. The half-year, one-year, and two-year local tumor progression (endpoint-2) rate was 0%, 9.1%, and 27.3%. The two-year overall survival rate was 100%.

CONCLUSIONS

Ethiodized oil tumor marking enables to demarcate small HCCs that were invisible on unenhanced CT. It potentially allows a safe and complete ablation in subsequent CT-guided IRE.

In Vitro Characterization of a Novel Type of Radiopaque Doxorubicin-Loaded Microsphere

PURPOSE

To evaluate and compare the material characteristics of a novel type of radiopaque doxorubicin-loaded microsphere (V-100) with radiopaque and non-radiopaque doxorubicin-loaded microspheres.

MATERIALS AND METHODS

The prototype V-100 featuring inherent radiopacity and three available commercial controls (DC-Bead-LUMI™-70-150, Embozene-Tandem™-100 and DC-Bead™-M1) were analyzed before and after doxorubicin loading (37.5 mg doxorubicin/1 ml microspheres) in suspension with aqua and/or aqua/iodixanol-320. Study goals included inherent radiopacity [e.g., using conventional computed tomography (CT)], doxorubicin loading efficacy, morphology using light and fluorescence microscopy, size distribution using laser diffraction/light scattering, time-in-suspension, rheological properties using rheometer analysis, and microsphere stability observed over a period of 5 days after doxorubicin loading.

RESULTS

V-100 showed good inherent radiopacity without adverse imaging artifacts. Under conventional CT, the quantitative radiopacity was as follows: 480.4 ± 2.9HU for V-100, 2432.7 ± 3.2HU for DC-Bead-LUMI™-70-150, 118.1 ± 3.0HU for Embozene-Tandem™-100, and 19.8 ± 1.5HU for DC-Bead™-M1. All of the types of microspheres showed a similar loading efficiency (> 98%) after 24 h; however, there were slower doxorubicin loading velocities for the radiopaque microspheres. The doxorubicin-loaded V-100 and Embozene-Tandem™-100 showed typical narrow-sized distributions. In aqua/iodixanol-320 suspension, doxorubicin-loaded V-100 showed the best suspension features and ideal deformability and elasticity characteristics. Similar to other microspheres, doxorubicin-loaded V-100 was very stable and storable for at least 5 days.

CONCLUSION

V-100 is a promising novel type of radiopaque doxorubicin-loaded microsphere. Compared with the controls, V-100 shows good inherent radiopacity without adverse imaging artifacts and with comparable doxorubicin loading efficacy. Further advantages of V-100 include narrow-sized distribution and excellent suspension, rheology, and stability features.

The opacity of mineral ion-loaded bead (DC beads®) on low-keV monochromatic images from dual energy CT and T1-weighted gradient-echo MRI

PURPOSE

To evaluate the opacity of DC beads^® (DCB) loaded with mineral ions on low-keV monochromatic images from dual energy computed tomography (DECT) and T1-weighted gradient-echo (T1-GRE) MRI.

MATERIALS AND METHODS

Fe²⁺ or Ca²⁺-loaded DCBs were prepared by mixing DCBs in 100 mM FeSO₄ or CaSO₄ solution and scanned by DECT from 10 min to 27 h after mixing. The Hounsfield units (HUs) of sedimented DCBs on 40-keV monochromatic images were measured. Next, we mixed DCBs in 100, 10, 5 and 1 mM FeSO₄ solutions, and scanned these solutions from 15 to 120 min after mixing using a 3 T MR scanner. The signal-noise ratios (SNRs) of sedimented DCBs on T1-GRE were measured. Venous blood was scanned to compare with DCBs.

RESULTS

The CT values of DCBs in FeSO₄ and CaCl₂ solutions gradually increased, and were 113.3 and 43.1 HU at 27 h, respectively; that of blood was 17.8 HU. The SNR of DCB in 1 mM FeSO₄ solution increased and achieved equilibrium at 120 min, and was 120.5 and higher than in the other FeSO₄ solutions. The SNR of blood was 49.7.

CONCLUSION

Optimally Fe²⁺-loaded DCBs can be discriminated from venous blood on 40-keV monochromatic images from DECT and T1-GRE.