Polymerization Properties of n-Butyl Cyanoacrylate Mixed with Ethiodized Oil in the Lymphatic System: In Vivo Investigation in a Rabbit Model.

PURPOSE: To evaluate the polymerization properties of a mixture of n-butyl cyanoacrylate (nBCA) and ethiodized oil in the lymphatic system using an animal model. MATERIALS AND METHODS: Nineteen male Japanese White rabbits underwent 28 lymphatic embolization procedures under fluoroscopic guidance using manually injected mixtures of nBCA and ethiodized oil at ratios of 1:2 (nBCA density of 33%), 1:4 (20%), 1:6 (14%), and 1:8 (11%) via the popliteal lymph node. The time required for polymerization and the distance traveled by the mixture were evaluated and compared among the groups using the Kruskal-Wallis test. Histopathologic intergroup comparisons and time-course changes were also evaluated using embolized lymph nodes. RESULTS: Among 23 successful procedures, the mean polymerization times were 14 ± 3, 88 ± 93, 331 ± 292, and 932 seconds ± 540 and the mean distances traveled were 13 ± 10, 31 ± 44, 85 ± 89, and 108 mm ± 35 in the 33% (n = 5), 20% (n = 6), 14% (n = 6), and 11% (n = 6) groups, respectively. The 11% group demonstrated a significantly longer polymerization time than the 33%, 20%, and 14% groups and distance traveled than the 33% group. Pathologically, the embolized lymph nodes showed inflammatory changes and massive necrosis regardless of the nBCA density. CONCLUSIONS: Polymerization times and distances traveled were increased when nBCA was diluted with increasing quantitites of ethiodized oil in this rabbit model of lymphatic embolization. These relationships should be considered when dilution is prescribed for clinical use.

Sustained release of arsenic trioxide benefits interventional therapy on rabbit VX2 liver tumor.

The benefit of chemotherapy as a constituent of transcatheter arterial chemoembolization (TACE) is still in debate. Recently we have developed arsenic trioxide nanoparticle prodrug (ATONP) as a new anticancer drug, but its systemic toxicity is a big issue. In this preclinical TACE study, ATONP emulsified in lipiodol behaved as drug-eluting bead manner. Sustained release of arsenic from ATONP within occluded tumor caused very low arsenic level in plasma, avoiding the "rushing out" effect as ATO did. Correspondingly, intratumoral arsenic accumulation and inorganic phosphate deprivation were simultaneously observed, and arsenic concentration was much higher as ATONP was transarterially administered than ATO, or intravenously injected. Tumor necrosis and apoptosis were remarkably more severe in ATONP group than ATO, but no significant hepatic and renal toxicity was perceived. In brief, ATONP alleviated arsenic toxicity and boosted the therapeutic effect of TACE via Pi-activated drug sustainable release.

Conventional versus drug-eluting beads chemoembolization for infiltrative hepatocellular carcinoma: a comparison of efficacy and safety.

BACKGROUND: To compare the efficacy and safety between conventional transarterial chemoembolization (cTACE) and drug-eluting beads TACE (DEB-TACE) in patients with infiltrative hepatocellular carcinoma (iHCC). METHODS: A total of 89 iHCC patients who were treated with either cTACE (n = 33) or DEB-TACE (n = 56) between April 2013 and September 2017 were included in this retrospective study. Patients with the situations that might have a poor outcome were defined as advanced disease including Child-Pugh class B, bilobar lesions, tumor size greater than 10 cm, ECOG 1-2, tumor burden of 50-70%, and the presence of ascites, arterioportal shunt (APS), and portal venous tumor thrombus (PVTT). The tumor response was measured 1-month and 3-month after the procedure. Progression-free survival (PFS) was calculated. Toxicity was graded by Common Terminology Criteria for Adverse Events v5.0 (CTCAE v5.0). The differences in tumor response, PFS, and toxicity were compared between the DEB-TACE group and cTACE group. RESULTS: At 1-month and 3-month after the procedure, the objective response rate (ORR) in the overall study population was similar in DEB-TACE group and cTACE group. The disease control rate (DCR), at 1-month after the procedure, was significantly higher in the patients treated with DEB-TACE relative to those treated with cTACE (P = 0.034), while after 3 months, the difference did not differ between two groups. DEB-TACE showed a higher DCR than cTACE in patients with tumor size greater than 10 cm (P = 0.036) or associated with APS (P = 0.030) at 1-month after the procedure, while after 3 months, the difference was only noted in patients with APS (P = 0.036). The median PFS in DEB-TACE group was 96 days, while in cTACE group was 94 days, and there was no difference in PFS between two groups (P = 0.831). In the side effect analysis, abdominal pain (P = 0.034) and fever (P = 0.009) were more frequently present in the cTACE group than DEB-TACE group, but there was no difference in high grade liver toxicity between the two groups. CONCLUSIONS: Compared to cTACE, DEB-TACE offers slightly better DCR and tolerability for iHCC patients, particularly in patients associated with APS and large tumor size. However, DEB-TACE does not provide higher PFS than cTACE.

Photon and electron backscatter dose and energy spectrum analysis around Lipiodol using flattened and unflattened beams.

PURPOSE: The aim of the current study was to evaluate the backscatter dose and energy spectrum from the Lipiodol with flattening filter (FF) and flattening filter-free (FFF) beams. Moreover, the backscatter range, that was defined as the backscatter distance (BD) are revealed. METHODS: 6 MVX FF and FFF beams were delivered by TrueBeam. Two dose calculation methods with Monte Carlo calculation were used with a virtual phantom in which the Lipiodol (3 × 3 × 3 cm3 ) was located at a depth of 5.0 cm in a water-equivalent phantom (20 × 20 × 20 cm3 ). The first dose calculation was an analysis of the dose and energy spectrum with the complete scattering of photons and electrons, and the other was a specified dose analysis only with scattering from a specified region. The specified dose analysis was divided into a scattering of primary photons and a scattering of electrons. RESULTS: The lower-energy photons contributed to the backscatter, while the high-energy photons contributed the difference of the backscatter dose between the FF and FFF beams. Although the difference in the dose from the scattered electrons between the FF and FFF beams was within 1%, the difference of the dose from the scattered photons between the FF and FFF beams was 5.4% at a depth of 4.98 cm. CONCLUSIONS: The backscatter range from the Lipiodol was within 3 mm and depended on the Compton scatter from the primary photons. The backscatter dose from the Lipiodol can be useful in clinical applications in cases where the backscatter region is located within a tumor.

A Nanoemulsion with A Porphyrin Shell for Cancer Theranostics.

A nanoemulsion with a porphyrin shell (NewPS) was created by the self-assembly of porphyrin salt around an oil core. The NewPS system has excellent colloidal stability, is amenable to different porphyrin salts and oils, and is capable of co-loading with chemotherapeutics. The porphyrin salt shell enables porphyrin-dependent optical tunability. The NewPS consisting of pyropheophorbide a mono-salt has a porphyrin shell of ordered J-aggregates, which produced a narrow, red-shifted Q-band with increased absorbance. Upon nanostructure dissociation, the fluorescence and photodynamic reactivity of the porphyrin monomers are restored. The spectrally distinct photoacoustic imaging (at 715 nm by intact NewPS) and fluorescence increase (at 671 nm by disrupted NewPS) allow the monitoring of NewPS accumulation and disruption in mice bearing KB tumors to guide effective photodynamic therapy. Substituting the oil core with Lipiodol affords additional CT contrast, whereas loading paclitaxel into NewPS facilitates drug delivery.

Development of pumping emulsification device with glass membrane to form ideal lipiodol emulsion in transarterial chemoembolization.

PURPOSE: To evaluate a pumping emulsification device that can improve the physiochemical properties and stability of lipiodol emulsion for conventional transarterial chemoembolization. MATERIALS AND METHODS: A pumping emulsification device constructed of a glass membrane with a hydrophobic surface with pore size of 50 µm in diameter was placed between two syringe adaptors. Epirubicin solutions were mixed with lipiodol with pumping exchanges using the emulsification device or a three-way cock. The ratios of epirubicin solution to lipiodol were 1:2 or 1:1. A total of 120 emulsions were created. RESULTS: The emulsification device showed significantly higher percentages of water-in-oil when compared with the three-way cock (97.9 % vs. 68.9 % in 1:2 ratio, and 82.1 % vs. 17.8 % in 1:1 ratio, p < .001). Droplet sizes in the emulsification device were more homogenous. Mean droplet sizes and viscosities in the emulsification device did not show any significant changes for 30 min after pumping, whereas in the three-way cock, the droplet sizes significantly enlarged and viscosities significantly decreased (p=.023 and p=.002). CONCLUSION: The emulsification device can form a high percentage of water-in-oil emulsion with stable droplets sizes and viscosities. This developed device is promising to increase therapeutic effects in conventional transarterial chemoembolization. KEY POINTS: • We developed new device for transarterial chemoembolization for liver cancer. • The device can improve the physiochemical properties of lipiodol emulsion. • The device can increase the therapeutic effects in conventional transarterial chemoembolization.

Techniques to Form a Suitable Lipiodol-Epirubicin Emulsion by Using 3-Way Stopcock Methods in Transarterial Chemoembolization for Liver Tumor.

PURPOSE: To compare physicochemical properties of emulsions of ethiodized oil (Lipiodol; Guerbet, Villepinte, France) and epirubicin prepared using different techniques for conventional transarterial chemoembolization. MATERIALS AND METHODS: Lipiodol was mixed with epirubicin solution (8.33 mg/mL) by using a 3-way stopcock. The following technical parameters were compared: ratio of epirubicin solution to Lipiodol (1:2 vs 1:1), number of pumping exchanges through the stopcock (20 exchanges vs 10 exchanges), pumping speed (1 s/push vs 2 s/push), and first push syringe (epirubicin solution vs Lipiodol). RESULTS: The mean percentage of water-in-oil was 70.45 ± 1.51 in the 1:2 epirubicin-Lipiodol ratio and 16.03 ± 2.95 in the 1:1 ratio (P < .001). The first push syringe did not influence emulsion type. Median droplet sizes were significantly larger in the slower pumping speed (52.0 µm in 2 s vs 33.7 µm in 1 s; P < .001), whereas there was no significant difference in number of pumping exchanges. Droplet sizes enlarged during 30 minutes after pumping. Viscosity was lower in the 1:1 ratio and the slower pumping speed. Viscosity decreased during 30 minutes after pumping. CONCLUSIONS: The ratio of epirubicin to Lipiodol is a significant factor to form water-in-oil emulsions with higher viscosity. The percentage of water-in-oil is limited to 70% using current pumping techniques. The pumping speed strongly influences droplet size and viscosity.

Fluorescent iodized emulsion for pre- and intraoperative sentinel lymph node imaging: validation in a preclinical model.

PURPOSE: To validate the usefulness of a newly developed tracer for preoperative gastric sentinel lymph node (LN) (SLN) mapping and intraoperative navigation after a single preoperative submucosal injection in rat and beagle models. MATERIALS AND METHODS: This study was approved by the Experimental Animal Ethical Committee of Yonsei University College of Medicine according to the eighth edition of the Guide for the Care and Use of Laboratory Animals published in 2011. An emulsion was developed that contained indocyanine green in iodized oil, which can be visualized with both computed tomography (CT) and near-infrared (NIR) optical imaging and has the property of delayed washout. This emulsion was injected into the footpad of rats (n = 6) and the gastric submucosa of beagles (n = 8). CT lymphography was performed. The degree of enhancement of popliteal LNs was measured in rats, and the enhancing LNs were identified and the degree of enhancement of the enhancing LNs was measured in beagles. Next, NIR imaging was performed in beagles during open, laparoscopic, and robotic surgery to identify LNs containing the fluorescent signals of indocyanine green. The enhanced LNs detected with CT lymphography and NIR imaging were matched to see if they corresponded. RESULTS: Preoperative CT lymphography facilitated SLN mapping, and 26 SLNs were identified in eight beagles. NIR imaging enabled high-spatial-resolution visualization of both SLNs and the intervening lymphatic vessels and was useful for intraoperative SLN navigation. CONCLUSION: SLN mapping with fluorescent iodized oil emulsion is effective and feasible for both CT and NIR imaging.

Investigation of hepatobiliary disposition of doxorubicin following intrahepatic delivery of different dosage forms.

Unresectable, intermediate stage hepatocellular carcinoma (HCC) is often treated palliatively in humans by doxorubicin (DOX). The drug is administered either as a drug-emulsified-in-Lipiodol (DLIP) or as drug loaded into drug eluting beads (DEB), and both formulations are administered intrahepatically. However, several aspects of their in vivo performance in the liver are still not well-understood. In this study, DLIP and DEB were investigated regarding the local and systemic pharmacokinetics (PK) of DOX and its primary metabolite doxorubicinol (DOXol). An advanced PK-multisampling site acute in vivo pig model was used for simultaneous sampling in the portal, hepatic, and femoral veins and the bile duct. The study had a randomized, parallel design with four treatment groups (TI-TIV). TI (n = 4) was used as control and received an intravenous (i.v.) infusion of DOX as a solution. TII and TIII were given a local injection in the hepatic artery with DLIP (n = 4) or DEB (n = 4), respectively. TIV (n = 2) received local injections of DLIP in the hepatic artery and bile duct simultaneously. All samples were analyzed for concentrations of DOX and DOXol with UPLC-MS/MS. Compared to DLIP, the systemic exposure for DOX with DEB was reduced (p < 0.05), in agreement with a slower in vivo release. The approximated intracellular bioavailability of DOX during 6 h appeared to be lower for DEB than DLIP. Following i.v. infusion (55 min), DOX had a liver extraction of 41 (28-53)%, and the fraction of the dose eliminated in bile of DOX and DOXol was 20 (15-22)% and 4.2 (3.2-5.2)%, respectively. The AUCbile/AUCVP for DOX and DOXol was 640 (580-660) and 5000 (3900-5400), respectively. In conclusion, DLIP might initially deliver a higher hepatocellular concentration of DOX than DEB as a consequence of its higher in vivo release rate. Thus, DLIP delivery results in higher intracellular peak concentrations that might correlate with better anticancer effects, but also higher systemic drug exposure and safety issues.

Basic study of a mixture of N-butyl cyanoacrylate, ethanol, and lipiodol as a new embolic material.

PURPOSE: To clarify the configuration change of N-butyl cyanoacrylate (NBCA) polymerization with increasing proportion of ethanol, the properties of a mixture of NBCA with lipiodol plus ethanol (NLE), and the feasibility of use of NLE for aneurysm packing in a swine model. MATERIALS AND METHODS: The polymerization configuration of NLE was explored using ratios of 1-4 parts NBCA and 1-3 parts ethanol per 1 part of lipiodol; a 1:1 ratio of NBCA to lipiodol (NLE110) was used as a control. The distance that NLE migrated into saline flowing in a tube was measured. A carotid artery aneurysm was created in each of 18 swine. Aneurysmal packing with three configurations--NLE110, NLE at a ratio of 1:1:2 (NLE112), and NLE at a ratio of 1:1:3 (NLE113)--was attempted in six swine for each configuration. RESULTS: Regardless of NBCA composition, medium-sized droplets, a single large droplet, and a noodle-shaped extrusion were observed in NLE with lipiodol versus ethanol ratios of 1:1, 1:2, and 1:3. NLE110 migrated as viscous fluid to 190 cm from the injection site, whereas NLE112 migrated for 81 cm ± 11 and NLE113 migrated for 74 cm ± 9. Instant outflow of NLE110 from the six aneurysms caused occlusion of the parent artery, with adhesion to the microcatheter. Packing was achieved with minimal adhesion for all six of the aneurysms packed with NLE112 or with NLE113. CONCLUSIONS: With high ratios of ethanol, the NLE polymerization configuration acquired solid-like properties with potent occlusive ability and negligible adhesion to the microcatheter, suggesting its feasibility for packing of aneurysms.

Properties of N-butyl cyanoacrylate-iodized oil mixtures for arterial embolization: in vitro and in vivo experiments.

PURPOSE: To examine the properties of N-butyl cyanoacrylate (NBCA) and iodized oil (lipiodol [Lip]) in vitro and in vivo for safe and effective embolization. MATERIALS AND METHODS: Viscosity, polymerization time, and diffusing capacity were evaluated according to the NBCA/Lip ratio in vitro. Additionally, the effect of the NBCA/Lip ratio on arterial embolization was evaluated in vivo; various ratios of NBCA/Lip were injected into the renal arteries of adult beagles, after which the embolization effect following transcatheter arterial embolization was quantitatively investigated histopathologically and using computed tomography (CT) volumetry. RESULTS: The viscosity of NBCA/Lip increased, polymerization time was prolonged, and diffusing capacity increased as the NBCA density decreased. As the NBCA density decreased, embolic material was recognized in smaller diameter arteries, and embolization of a larger vascular bed was accomplished. The NBCA/Lip mixture with a low density of NBCA was located more peripherally from the catheter tip, and embolization of more peripheral and smaller diameter arteries was achieved. CONCLUSIONS: The relationships of properties of NBCA/Lip in vitro and embolization effects in vivo of various ratios of NBCA/Lip were quantitatively examined and compared. The results of this study are useful for safe and effective embolization.

Meta-analysis of interstitial pneumonia in studies evaluating iodine-131-labeled lipiodol for hepatocellular carcinoma using exact likelihood approach.

PURPOSE: Iodine-131-labeled lipiodol is currently licensed for unresectable hepatocellular carcinoma with portal thrombosis. It is thought to be well tolerated. Cases of interstitial pneumonia have been reported, but their frequency (≈2%) has not been well estimated. Quantifying adverse drug event frequency requires an appropriate statistical approach because standard methods are biased. METHODS: To estimate the frequency of interstitial pneumonia in patients with hepatocellular carcinoma receiving iodine-131-labeled lipiodol, we conducted a systematic review of English articles using MEDLINE and EMBASE. All types of articles were considered except case reports. Primary outcome measure was symptomatic interstitial pneumonia based on investigators' judgment. All pooled analyses were based on a random effects meta-analysis model using an exact likelihood approach based on the binomial within-study distribution. RESULTS: Ten studies, including 142 patients, used low activity per dose, ranging from 0.3 to 1.1 GBq. No respiratory adverse event was noticed in these studies. Eighteen studies, including 542 patients, evaluated higher activity per dose, around 2.2 GBq; 24 cases of interstitial pneumonia were reported in these studies. Estimated frequency of interstitial pneumonia was 1.6% (95%CI, 0.4-6.4%) after one high dose and 4.1% (95%CI, 1.0-16.0%) after two or more high doses. CONCLUSIONS: The frequency of interstitial pneumonia appears higher and more precise than previously estimated. The risk appears to be related to the number of injections and the dose level per injection. Generalized linear mixed models using the exact binomial within-study distribution initially described to summarize data on diagnostic evaluation could be relevant for drug-related adverse reaction frequency assessment.

Tuning the lipophilic nature of pyclen-based 90Y3+ radiopharmaceuticals for ß-radiotherapy.

Pyclen-dipicolinate chelates proved to be very efficient chelators for the radiolabeling with ß--emitters such as 90Y. In this study, a pyclen-dipicolinate ligand functionalized with additional C12 alkyl chains was synthesized. The radiolabeling with 90Y proved that the addition of saturated carbon chains does not affect the efficiency of the radiolabeling, whereas a notable increase in lipophilicity of the resulting 90Y radiocomplex was observed. As a result, the compound could be extracted in Lipiodol® and encapsulated in biodegrable pegylated poly(malic acid) nanoparticles demonstrating the potential of lipophilic pyclen-dipicolinate derivatives as platforms for the design of radiopharmaceuticals for the treatment of liver or brain cancers by internal radiotherapy.

Chemical stability of oil-infused polyethylene.

Ultra-high molecular weight polyethylene (UHMWPE) can be made radiopaque for medical imaging applications through the diffusion of an iodised oil-based contrast agent (Lipiodol Ultra Fluid). A similar process is used for Vitamin E incorporated polyethylene which provides antioxidant properties. This study aimed to investigate the critical long-term properties of oil-infused medical polyethylene after 4 weeks of accelerated thermal ageing. Samples treated with an oil (Vitamin E or Lipiodol) had a higher oxidation stability than currently used medical grade polyethylene, indicated by a smaller increase in oxidation index after ageing (Vitamin E + 36%, Lipiodol +40%, Untreated +136%, Thermally treated +164%). The tensile properties of oil treated polyethylene after ageing were significantly higher than the Untreated and Thermally treated controls (p<0.05) indicating less mechanical degradation. There was also no alteration in the percentage crystallinity of oil treated samples after ageing, though the radiopacity of the Lipiodol treated samples reduced by 54% after ageing. The leaching of oil with time was also investigated; the leaching of Lipiodol and Vitamin E followed the same trend and reached a steady state by two weeks. Overall, it can be concluded that the diffusion of an oil-based fluid into polyethylene not only increases the oxidative and chemical stability of polyethylene but also adds additional functionality (e.g. radiopacity) providing a more suitable material for long-term medical applications.

Glue Embolization of Lymphopseudoaneurysm for Chylous Ascites after Retroperitoneal Surgery.

OBJECTIVE: To assess the safety and efficacy of lymphopseudoaneurysm (LPA) glue (n-butyl cyanoacrylate [NBCA]) embolization in the management of chylous ascites after retroperitoneal surgery. MATERIALS AND METHODS: A retrospective analysis from January 2014 to October 2018 was performed in six patients (4 females and 2 males; mean age, 45.3 ± 14.2 years; range, 26-61 years) who underwent LPA embolization for chylous ascites developing after retroperitoneal surgery involving the perirenal space (four donor nephrectomies, one partial nephrectomy, and one retroperitoneal lymphadenectomy). After placing a percutaneous drainage catheter into the LPA or adjacent lymphocele, embolization was performed by filling the LPA itself with a mixture of glue and Lipiodol (Guerbet). RESULTS: Daily drainage from percutaneously placed drains exceeded 300 mL/day despite medical and surgical treatment (volume: mean, 1173 ± 1098 mL; range, 305-2800 mL). Intranodal lymphangiography was performed in four of the six patients and revealed leakage in 2 patients. Percutaneous embolization of the LPA was successful in all patients using an NBCA and Lipiodol mixture in a ratio of 1:1-1:2 (volume: mean, 4.3 ± 1.1 mL; range, 3-6 mL). Chylous ascites was resolved and the drainage catheter was removed in all patients within 4 days after the procedure (mean, 2.0 ± 1.8 days; range, 0-4 days). No procedure-related complications or recurrence of chylous ascites occurred during a mean follow-up period of 37.3 months (range, 21.1-48.4 months). CONCLUSION: Glue embolization of LPA has the potential to be a feasible and effective treatment method for the management of chylous ascites after retroperitoneal surgery.

Empirical 188Re-HDD/lipiodol intra-arterial therapy based on tumor volume, in patients with solitary inoperable hepatocellular carcinoma.

OBJECTIVE: This study aimed to assess the potential benefits and tolerability of an empirical dose of approximately 0.8-1.2 mCi (29.6-44.4 MBq) of Re-4-hexadecyl-1-2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol/lipiodol (Re-HDD/lipiodol) per milliliter of tumor volume, administered after super-selection of the tumor feeding branches of hepatic artery for treatment of inoperable hepatocellular carcinoma (HCC). METHODS: Patients with advanced HCC or classified as inoperable, with no demonstrated extrahepatic disease and no significant comorbidities were eligible. The patients selected for this study had a single tumoral lesion, measuring less than 150 cc. The range of total activity administered was between 30 and 100 mCi (1.2-3.7) GBq Re-HDD/lipiodol, administered in the super selected branches of the hepatic artery supplying the tumor in 42 Patients. Whole-body scintigraphies and single-photon emission computed tomography-computed tomography (SPECT-CT) of the liver including tumor were performed at four-time points after injection. Absorbed doses to the various organs were calculated according to the Medical Internal Radiation Dose formalism. Blood and urine samples were collected at multiple time points until 72 h after injection. Hematological, hepatic and pulmonary toxicity was assessed until 12 weeks after administration using the Common Toxicity Criteria for Adverse Events (version 3.0) scale. Responses were evaluated on contrast enhanced computed tomography (CECT) and by alfa-fetoprotein (AFP) level monitoring. RESULTS: About 40.6 ± 4.8% of the injected activity was excreted in the urine by 72 h after injection. The mean absorbed dose to the liver, lungs, stomach, kidney and intestine was 14.4 ± 1.8, 4.8 ± 0.6, 5.5 ± 1.1, 5.1 ± 0.7, and 6.5 ± 1.0 Gy (mean ± SD), respectively. Up to 6 days after administration, 26 of 44 patients had adverse events consisting of aggravations of preexisting laboratory changes (24 patients), fatigue (5 patients), vomiting (6 patients), fever (2 patients), right hypochondrial pain (8 patients), and pain at site of femoral catheter insertion (8 patients). Toxicity assessment at weeks 6 and 12 revealed two cases of mild worsening of liver function tests and no lung or hematological toxicity noted. Two patients were lost to follow-up after the 6-week visit. The response was assessed on CECT in all the remaining patients and the classification of results was more standardized when using European Association for the Study of the Liver (EASL) criteria rather than response evaluation criteria in solid tumors (RECIST) criteria. According to EASL criteria, 8 patients had a partial response, 28 patients had a complete response, 4 patients had progressive disease and 4 patients with stable disease were reported. Thirty-six patients had a baseline elevated AFP and on follow-up at 6 weeks, 6 of these patients showed stable AFP, progression in 4 patients and 26 showed a reduction. CONCLUSION: After the administration of 1.2-3.7 GBq Re-HDD/lipiodol based on empirical activity calculation of 0.8-1.2 mCi/mL of tumor volume, more than half of the patients in the present study had an objective response on imaging and biochemically. No significant adverse side effects were noted and most of the laboratory markers as well as symptoms returned to normal after 48-72 h post-administration. Selective administration of the radiopharmaceutical into the tumor feeding arteries gives a good anti-tumoral effect with minimal side effects and damage to surrounding normal liver tissue.

Is the Cessation of Blood Flow Faster than the Polymerization of an n-Butyl Cyanoacrylate-Lipiodol Mixture? An In Vitro Phantom Study.

PURPOSE: To compare the polymerization time of n-butyl cyanoacrylate (NBCA) and lipiodol mixture in a static model and a pulsating flow model simulating embolization procedure of small caliber arteries. MATERIALS AND METHODS: The polymerization time of NBCA-lipiodol mixture was measured by the morphological changes of a glue droplet in a petri dish. For the flow model, we used a 2-mm-inner-diameter polyvinyl alcohol tube connected to a pulsation pump. Bovine serum was supplied from the pump and circulated into the system at 30 ml/min and 60 bpm. A 0.64-mm-inner-diameter silicon microcatheter was inserted into this system, and then, 0.5 ml of glue was injected into the tube. The flow cessation time was defined as the time it took to stop the serum draining from the end of the tube. Six samples of 100, 66, 50, 40, 33, and 20 vol% NBCA were assessed. RESULTS: The median polymerization times for each concentration were 0.12, 3.72, 12.30, 27.41, 57.68, and 63.67 s, respectively. The median flow cessation times were 0.28, 0.78, 1.43, 3.75, 4.50, and 9.29 s, respectively. The flow cessation time was significantly shorter than the polymerization time for all samples except for 100 vol% cyanoacrylate (p < 0.05). CONCLUSION: The flow cessation time of cyanoacrylate glue was significantly shorter than the polymerization time in an in vitro experiment. The injected glue possibly stops the blood flow before the completion of polymerization in the vascular system.

Characterisation of the physical, chemical and mechanical properties of a radiopaque polyethylene.

Ultra-high molecular weight polyethylene has a low X-ray attenuation, hence, the performance of the polyethylene implants used for joint replacements cannot be directly investigated using X-ray-based imaging techniques. In this study, the X-ray attenuation of polyethylene was increased by diffusing an FDA-approved oil-based contrast agent (Lipiodol ultra fluid) into the surface of the samples, and the suitability of this novel radiopaque ultra-high molecular weight polyethylene for clinical applications was examined. Different levels of radiopacity were created by controlling the diffusion parameters, and the level of radiopacity was quantified from computed tomography scans and reported in Hounsfield units. The physical, chemical and tensile properties of the radiopaque ultra-high molecular weight polyethylene were examined and compared to untreated and thermally treated controls. The results of this study confirmed that for the samples treated at 115°C or less the diffusion of the contrast agent did not significantly alter the crystallinity (p = 0.7) or melting point (p = 0.4) of the polyethylene. Concomitantly, the tensile properties were not significantly different from the control samples (p > 0.05 for all properties). In conclusion, the radiopaque ultra-high molecular weight polyethylene treated for less than 18 h at a temperature of 115°C or below is a promising candidate for joint replacement applications as it can be identified in a standard X-ray while retaining the tensile properties of clinically used radiolucent ultra-high molecular weight polyethylene.

A Canine Model for Lymphangiography and Thoracic Duct Access.

OBJECTIVE: To evaluate the technical feasibility of intranodal lymphangiography and thoracic duct (TD) access in a canine model. MATERIALS AND METHODS: Five male mongrel dogs were studied. The dog was placed in the supine position, and the most prominent lymph node in the groin was accessed using a 26-gauge spinal needle under ultrasonography (US) guidance. If the cisterna chyli (CC) was not opacified by bilateral lymphangiography, the medial iliac lymph nodes were directly punctured and Lipiodol was injected. After opacification, the CC was directly punctured with a 22-gauge needle. A 0.018-in microguidewire was advanced through the CC and TD. A 4-Fr introducer and dilator were then advanced over the wire. The microguidewire was changed to a 0.035-in guidewire, and this was advanced into the left subclavian vein through the terminal valve of the TD. Retrograde TD access was performed using a snare kit. RESULTS: US-guided lymphangiography (including intranodal injection of Lipiodol [Guerbet]) was successful in all five dogs. However, in three of the five dogs (60%), the medial iliac lymph nodes were not fully opacified due to overt Lipiodol extravasation at the initial injection site. In these dogs, contralateral superficial inguinal intranodal injection was performed. However, two of these three dogs subsequently underwent direct medial iliac lymph node puncture under fluoroscopy guidance to deliver additional Lipiodol into the lymphatic system. Transabdominal CC puncture and cannulation with a 4-Fr introducer was successful in all five dogs. Transvenous retrograde catheterization of the TD (performed using a snare kit) was also successful in all five dogs. CONCLUSION: A canine model may be appropriate for intranodal lymphangiography and TD access. Most lymphatic intervention techniques can be performed in a canine using the same instruments that are employed in a clinical setting.

Pickering emulsions with ethiodized oil and nanoparticles for slow release of intratumoral anti-CTLA4 immune checkpoint antibodies.

BACKGROUND: Intratumorous immunotherapy for cancer is currently thriving. The aim of such local strategy is to improve the therapeutic index of these treatments, for higher on-target/on-tumor activity and less on-target/off-tumor adverse events. Strategies allowing for slow release of anti-CTLA4 in the tumor microenvironment could improve their clinical efficacy.The purpose of the study was to develop a radiopaque delivery platform to improve the targeting and exposure of intratumorous anti-CTLA4 antibodies for cancer immunotherapy. METHODS: Pickering emulsions of anti-CTLA4 antibodies were formulated with radiopaque ethiodized oil and poly-lactic-co-glycolic acid (PLGA) nanoparticles. We characterized the microscopic aspect and stability of such emulsions using Turbiscan. We monitored the release of anti-CTLA4 over time from these emulsions and evaluated their structure using mass spectrometry. We then tested the functionality of the released antibodies by preforming ex vivo competitive binding assays. Finally, we assessed the in vivo efficacy of intratumorous anti-CTLA4 Pickering emulsions. RESULTS: Pickering emulsions of ethiodized oil and PLGA nanoparticles (PEEPs) resulted in a radiopaque water-in-oil emulsion with average internal phase droplet size of 42±5 µm at day 7. Confocal microscopy showed that anti-CTLA4 antibodies were effectively encapsulated by ethiodized oil with PLGA nanoparticles located at the interface between the aqueous and the oily phase. Turbiscan analysis showed that emulsions were stable with continuous and progressive release of anti-CTLA4 antibodies reaching 70% at 3 weeks. Structural and functional analysis of the released antibodies did not show significant differences with native anti-CTLA4 antibodies. Finally, intratumorous anti-CTLA4 PEEPs were able to eradicate tumors and cure mice in a syngeneic immunocompetent preclinical tumor model. CONCLUSION: Pickering emulsions of ethiodized oil and PLGA is an innovative radiopaque delivery platform that does not alter the functionality of anti-CTLA4 immune checkpoint antibodies. Beyond local anti-CTLA4 applications, these emulsions might be used with other therapeutic molecules for optimal intratumorous or intra-arterial delivery of novel cancer immunotherapies.