A novel irinotecan-lipiodol nanoemulsion for intravascular administration: pharmacokinetics and biodistribution in the normal and tumor bearing rat liver.

Colorectal cancer is one of the most common cancers in the United States and treatment options are limited for patients who develop liver metastases. Several chemotherapeutic regimens have been used for transvascular liver-directed therapy in the treatment of colorectal liver metastases without clear evidence of superiority of one therapy over another. We describe the development of a novel nanoemulsion through combining irinotecan (IRI), a first line systemic agent used for the treatment of colon cancer, with lipiodol, an oily contrast medium derived from poppy seed oil, and evaluated its pharmacokinetic and biodistribution profile as a function of portal venous chemoembolization (PVCE) versus transarterial chemoembolization (TACE) delivery. The Tessari technique was used to create a stable emulsion (20 mg IRI mixed with 2 mL lipiodol) with resultant particle size ranging from 28.9 nm to 56.4 nm. Pharmacokinetic profile established through venous sampling in Buffalo rats demonstrate that the area under the curve (AUC0-∞) of IRI was significantly less after PVCE with IRI-lipiodol as compared to IRI alone (131 vs. 316 µg*min/mL, p-value = .023), suggesting significantly higher amounts of IRI retention in the liver with the IRI-lipiodol nanoemulsion via first-pass extraction. Subseqent biodistribution studies in tumor-bearing WAG/Rjj rats revealed more IRI present in the tumor following TACE versus PVCE (29.19 ± 12.33 µg/g versus 3.42 ± 1.62; p-value = .0033) or IV (29.19 ± 12.33 µg/g versus 1.05 ± 0.47; p-value = .0035). The IRI-lipiodol nanoemulsion demonstrated an acceptable hepatotoxicity profile in all routes of administration. In conclusion, the IRI-lipiodol nanoemulsion via TACE showed promise and warrants further investigation as an option for the treatment of metastatic colorectal cancer.

Occurrence of Vascular Lake Phenomenon Before Embolization for the Prediction of Lipiodol Uptake for Intermediate-Stage Hepatocellular Carcinoma Patients that Underwent cTACE.

PURPOSE: To compare Lipiodol uptake and tumor response in intermediate-stage hepatocellular carcinoma (HCC) with and without pre-embolization vascular lake phenomenon (VLP) and to identify the incidence and predictive factors of this phenomenon, in patients treated by conventional transarterial chemoembolization (cTACE). MATERIALS AND METHODS: This retrospective study included 151 consecutive patients with intermediate HCC totaling 232 nodules, who underwent cTACE from June 2015 to October 2018. Patients were divided into two groups according to the presence of VLP before embolization. Initial Lipiodol uptake was assessed using post-cTACE computed tomography (CT) within 1-1.5 months after cTACE. Enhanced CT or magnetic resonance imaging was performed at 6 months after the procedure to assess local recurrence and distant metastasis. RESULTS: The VLP was demonstrated in 21.85% (33/151) patients and 16.81% (39/232) nodules on the super-selective angiography. On nodule-based analysis, significantly better Lipiodol uptake (p < 0.001) and higher ORR (60.61% vs. 26.49%, p < 0.001) and DCR (87.88% vs. 51.66%, p < 0.001) were observed in the VLP group compared to the non-VLP group. The multivariate logistic regression analysis showed that the presence of VLP (OR 6.431, 95% CI 2.495-16.579) might be a predictive factor for better Lipiodol uptake. Univariate and multivariate logistic regression analysis showed that poor differentiation of tumor (OR 6.397, 95% CI 2.804-19.635) remained predictive for the VLP. CONCLUSION: The incidence of VLP before embolization is 21.19%. The presence of VLP is well correlated with tumor Lipiodol uptake after cTACE and may be a new predictive factor for evaluation of cTACE efficacy and prognosis of intermediate HCC.

Transcatheter arterial chemoembolization (TACE) with iRGD peptide in rabbit VX2 liver tumor.

PURPOSE: Transcatheter arterial chemoembolization (TACE) is the first-line therapy for unresectable hepatocellular carcinoma (HCC). However, its therapeutic effects are hampered by the poor distribution of anticancer drugs in tumors. iRGD, a novel tumor-penetrating peptide, enhances the penetration distance and therapeutic efficacy of anticancer drugs. Herein, we evaluated the therapeutic effects of iRGD coupled with TACE in the rabbit VX2 liver tumor model. SUBJECTS AND METHODS: This study had two stages: tumor permeability assay and anticancer efficacy evaluation. In the tumor permeability assay, we coadministered TACE with either iRGD + lipiodol-doxorubicin emulsion (LDE) or LDE in the rabbit VX2 liver tumor model. We evaluated the doxorubicin (DOX) distribution at predetermined times by immunofluorescence microscopy. To evaluate anticancer efficacy, we administered saline, LDE, or iRGD + LDE to tumor-grafted rabbits. We measured tumor volume using magnetic resonance scanning. We quantified the expression levels of Bax, Bcl-2, and cleaved caspase-3 using Western blot (WB) analysis and determined the apoptosis rate in tumor cells using transferase-mediated dUTP nick-end labeling assay. RESULTS: The iRGD + LDE infusion significantly increased the DOX concentration and DOX penetration in tumors compared with the LDE infusion (P < 0.05). The antitumor efficacy of the iRGD + LDE in tumor inhibition was higher than that of the other treatments (P < 0.05). Besides, iRGD + LDE induced more apoptosis (P < 0.05). CONCLUSIONS: We demonstrated that iRGD coadministered with TACE is effective against HCC.

Drug Release Property of Lipiodol Emulsion Formed by Glass Membrane Emulsification Device for Transarterial Chemoembolization.

PURPOSE: To evaluate physiochemical characteristics of emulsions formed by a modified emulsification device and to compare in vitro drug release properties of ethiodized oil (Lipiodol)-drug solution emulsion formed by the device and a 3-way-stopcock for conventional transarterial chemoembolization. MATERIALS AND METHODS: A V-shaped pumping emulsification device with a 100-µm-micropore glass membrane was developed to reduce the resistance of pumping. Epirubicin solution was mixed with Lipiodol (ratio 1:2) with pumping exchanges through the device. The percentage of water-in-oil (W/O) and droplet size distribution and viscosity were evaluated. The in vitro drug release properties were compared between using the device and a 3-way-stopcock. RESULTS: Percentage of W/O was 98.45 ± 0.03%. The median droplet size was 22.58 ± 1.70 µm, and the viscosity was 143.70 ± 12.36 cP. The released epirubicin at 0 min was 1.73 ± 1.05% in the device, whereas 41.02 ± 7.27% in a 3-way-stopcock (P < 0.001). The half-life of release (t50%) of the device was significantly longer than that of a 3-way-stopcock (175 ± 25 vs. 8 ± 6 min, P < 0.001). CONCLUSION: The V-shaped emulsification device with a 100-µm-micropore glass membrane can form nearly 100% W/O emulsion with homogenous droplet sizes. Emulsion formed by the device showed a slower epirubicin release property compared with that of a 3-way-stopcock.

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.

Lipiodol retention pattern after TACE for HCC is a predictor for local progression in lesions with complete response.

BACKGROUND: To evaluate the predictive value of the lipiodol retention pattern for local progression of HCC with a complete response (CR) on CT according to mRECIST criteria after a first session of conventional chemoembolization (cTACE). METHODS: From January 2014 to May 2016 all consecutive patients undergoing a first cTACE session for HCC were identified. Inclusion criteria were the presence of ≤3 HCCs and available pre- and post-cTACE CT. Tumor response was classified according to mRECIST criteria. The analysis focused on tumors with a CR. The lipiodol retention pattern in these tumors was classified as complete (C-Lip, covering the entire tumor volume), or incomplete (I-Lip). Local progression was defined as the reappearance of areas of enhancement on arterial-phase images with washout on portal/delayed phase images within 2 cm from treated tumors on follow-up CT. RESULTS: The final population included 50 patients with 82 HCCs. A total of 46 (56%) HCCs were classified with a CR, including 16 (35%) with I-Lip, and 30 (65%) with C-Lip. After a median follow-up of 14 months (3.2-35.9 months), 15/16 (94%) and 10/30 (30%) of I-Lip and C-Lip HCCs showed local progression on CT, respectively (p < 0.001), with no significant difference in the time to progression (mean 11.1 ± 2 vs. 13.4 ± 3 months for I-Lip and C-Lip, respectively p = 0.51). CONCLUSIONS: HCCs with incomplete lipiodol retention after a first cTACE session have a high risk of local progression even when there is a CR according to mRECIST, and should be considered to be incompletely treated.

Analysis of Lipiodol uptake in angiography and computed tomography for the diagnosis of malignant versus benign hepatocellular nodules in cirrhotic liver.

OBJECTIVES: To evaluate the diagnostic value of Lipiodol distribution in angiography and CT to differentiate between hepatocellular carcinoma (HCC) and benign nodules of LI-RADS 3 and 4 lesions observed in MRI of liver cirrhosis. METHODS: This retrospective study included all patients with liver cirrhosis who had diagnosis of LI-RADS 3 or 4 lesions by MRI who underwent a Lipiodol-based angiography and post-interventional unenhanced CT- and liver biopsy. Two independent radiologists evaluated appearance, contrast enhancement, Lipiodol uptake in angiography, and morphological parameters (size, form, and density) of the lesions in unenhanced post-angiography CT. α-Fetoprotein (AFP) levels and pre-existing liver conditions were additionally taken into consideration. Differences between HCC lesions and benign nodules were analyzed. Sensitivity and specificity were calculated. P < 0.05 was considered as statistically significant. RESULTS: Of 60 patients (men, n = 42 [70.0%]; women, 18 [30.0%]; mean age, 61 ± 9.1 years) 36 (60.0%) had HCC and 24 (40.0%) benign nodules. Clear visibility in angiography (sensitivity [se], 100%; specificity [sp], 87.5%) with homogeneous or lacunar Lipiodol enhancement (se, 86.1%; sp, 100%) in consecutive CT can be diagnosed as HCC lesions in cirrhotic liver. Lesion form (p < 0.001), round or oval, and intense contrast (p < 0.001) are minor features which can facilitate the findings. Furthermore, patients with HCC showed a larger lesion size in CT (p = 0.026). CONCLUSION: Clearly detectable lesions in Lipiodol-based angiography and a homogeneous or lacunar enhancement in post-angiographic non-contrast CT allow for differentiation of intrahepatic lesions classified as LI-RADS 3 or 4 into benign vs. malign liver lesions with high sensitivity and specificity in patients with liver cirrhosis. Definite diagnosis may not require an additional biopsy. KEY POINTS: • Combination of clear visibility in Lipiodol-based angiography and homogeneous or lacunar enhancement in following native CT scan is HCC-defining. • In lesions classified with MRI as LI-RADS 3 or 4, evaluation based on Lipiodol angiography and following plain CT performed is highly sensitive and specific for the differentiation between HCC and benign nodules in a cirrhotic liver. • The results lead to an alternative pathway in the diagnosis of HCC in cirrhotic liver without the need of an additional liver biopsy.

Lipiodol deposition in portal vein tumour thrombus predicts treatment outcome in HCC patients after transarterial chemoembolisation.

OBJECTIVE: To study lipiodol deposition in portal vein tumour thrombus (PVTT) in predicting the treatment outcome of hepatocellular carcinoma (HCC) patients after transarterial chemoembolisation (TACE). METHODS: We retrospectively reviewed data from 379 HCC patients with PVTT who underwent TACE as the initial treatment at Sun Yat-Sen University Cancer Center from January 2008 to December 2015. Patients were grouped by positive and negative lipiodol deposition based on the extent of lipiodol deposition in PVTT. The overall survival (OS) and progression-free survival (PFS) were compared between negative and positive lipiodol deposition groups; furthermore, the value of the combinatorial evaluation of tumour responses and lipiodol deposition in PVTT in predicting prognosis was analysed in subgroup patients with stable disease (SD) after TACE. RESULTS: Of the 379 patients, 264 (69.7%) had negative and 115 (30.3%) had positive lipiodol deposition in PVTT after TACE. Multivariate analysis identified positive lipiodol deposition in PVTT as an independent prognostic factor for favourable OS (p = 0.001). The median OS and PFS of negative and positive lipiodol deposition groups were 4.70 vs. 8.97 months (p = 0.001) and 3.1 months vs. 5.8 months (p < 0.001). In subgroup patients, the median OS and PFS of negative and positive lipiodol deposition groups were 4.7 months vs. 10.5 months (p < 0.001) and 3.5 months vs. 7.0 months (p < 0.001), respectively. CONCLUSIONS: The patients with positive lipiodol deposition in PVTT had a longer OS than those with negative lipiodol deposition. Furthermore, the positive lipiodol deposition in PVTT can further differentiate HCC patients with favourable prognosis from SD patients. KEY POINTS: • Lipiodol deposition in PVTT is a prognostic indicator for HCC patients after TACE treatment. • Positive lipiodol deposition in PVTT is associated with a better prognosis.

Biodegradable Pickering emulsions of Lipiodol for liver trans-arterial chemo-embolization.

Water-in-oil (W/O) Lipiodol emulsions remain the preferable choice for local delivery of chemotherapy in the treatment of hepatocellular carcinoma. However, their low stability severely hampers their efficiency. Here, remarkably stable W/O Lipiodol emulsion stabilized by biodegradable particles was developed thanks to Pickering technology. The addition of poly(lactide-co-glycolide) nanoparticles (NPs) into the aqueous-phase of the formulation led to W/O Pickering emulsion by a simple emulsification process through two connected syringes. Influence of nanoparticles concentration and water/oil ratio on emulsion stability and droplet size were studied. All formulated Pickering emulsions were W/O type, stable for at least one month and water droplets size could be tuned by controlling nanoparticle concentration from 24 µm at 25 mg/mL to 69 µm at 5 mg/mL. The potential of these emulsions to efficiently encapsulate chemotherapy was studied through the internalization of doxorubicin (DOX) into the aqueous phase with a water/oil ratio of 1/3 as recommended by the medical community. Loaded-doxorubicin was released from conventional emulsion within a few hours whereas doxorubicin from stable Pickering emulsion took up to 10 days to be completely released. In addition, in vitro cell viability evaluations performed on the components of the emulsion and the Pickering emulsion have shown no significant toxicity up to relatively high concentrations of NPs (3 mg/mL) on two different cell lines: HUVEC and HepG2. STATEMENT OF SIGNIFICANCE: We present an original experimental research in the field of nanotechnology for biomedical applications. In particular, we have formulated, thanks to Pickering technology, a new therapeutic emulsion stabilized with biodegradable PLGA nanoparticles. As far as we know, this is the first therapeutic Pickering emulsion reported in the literature for hepatocellular carcinoma. Such a new emulsion allows to easily prepare a predictable and stable lipiodolized emulsion having all the required characteristics for optimum tumor uptake. As demonstrated throughout our manuscript, emulsions stabilized with these nanoparticles have the advantage of being biodegradable, biocompatible and less toxic compared to usual emulsions stabilized with synthetic surfactants. These findings demonstrate the plausibility of the use of Pickering emulsions for chemoembolization as a therapeutic agent in extended release formulations.

Comparison of Stable and Unstable Ethiodized Oil Emulsions for Transarterial Chemoembolization of Hepatocellular Carcinoma: Results of a Single-Center Double-Blind Prospective Randomized Controlled Trial.

PURPOSE: To compare the stability of stable and unstable water-in-oil emulsions and the efficacy and safety of these emulsions in a single-center, prospective double-blind trial of transarterial chemoembolization for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 812 patients with inoperable HCC were randomized (stable emulsion, n = 402; unstable emulsion, n = 410). The 2 emulsions were prepared by using the same protocol except that different solvents were used for chemotherapy agents, including epirubicin, lobaplatin, and mitomycin C. The solvent in the stable emulsion arm was contrast medium and distilled water, and the solvent in the unstable emulsion arm was distilled water. The primary endpoint was overall survival (OS), and secondary endpoints were time to progression (TTP), tumor response, adverse events (AEs), and plasma epirubicin concentrations. RESULTS: In vitro, stable emulsions did not occur until 1 day, and unstable emulsions, with a lower peak plasma concentration (P = .001) in vivo, exhibited rapid separation of the oil and aqueous phases after 10 minutes. Median OS times in the stable and unstable emulsion arms were 17.7 and 19.2 months, respectively (P = .81). No differences were found in TTP, tumor response, and AEs except for myelosuppression (anemia, 3.5% vs 7.6%; thrombocytopenia, 11.5% vs 17.7%), which was significantly more severe and frequent in the unstable emulsion arm (P = .013). CONCLUSIONS: Chemoembolization is equally effective with the use of stable and unstable emulsions, but the use of a stable emulsion has the advantage of less myelosuppression and a favorable pharmacokinetic profile.

Mechanism of Action, Pharmacokinetics, Efficacy, and Safety of Transarterial Therapies Using Ethiodized Oil: Preclinical Review in Liver Cancer Models.

PURPOSE: To systematically review mechanism of action, pharmacokinetics (PKs), efficacy, and safety of ethiodized oil-based locoregional therapy (LRT) for liver cancer in preclinical models. MATERIALS AND METHODS: A MEDLINE search was performed from 1988 to 2016. Search terms included hepatocellular carcinoma (HCC), HCC, liver-cell carcinoma, liver, hepatic, hepatocarcinoma, transarterial or chemoembolization, TACE, animal, Lipiodol, Ethiodol, iodized oil, and/or poppy-seed oil. Inclusion criteria were: publication in a peer-reviewed journal, an accepted animal model, and PK/safety/efficacy data reported. Exclusion criteria were: inadequate PK, safety, or efficacy data; anticancer drug name/dose not available; and article not in English. Outcomes included intratumoral anticancer drug uptake, PKs, tolerance, tumor response, and survival. RESULTS: Of 102 identified articles, 49 (49%) met the inclusion criteria. Seventeen, 35, and 2 articles used rat, rabbit, and pig models. Mechanism of action was investigated in 11 articles. Eleven articles reported drug uptake, PK, and tolerance data, showing 0.5%-9.5% of injected chemotherapy dose in tumor. Tumor-to-liver drug distribution ratios were 2-157. Toxicology data across 6 articles showed transient liver laboratory level elevations 1 day after LRT. There was no noteworthy liver or extrahepatic histologic damage. Nine articles reported tumor response, with 0%-30% viable tumor and -10% to -38% tumor growth at 7 days after LRT. Two articles reported survival, showing significantly longer survival after LRT vs untreated controls (56/60 d vs 33/28 d). Several articles described ethiodized oil mixed with radiopharmaceutical (n = 7), antiangiogenic (n = 6), gene (n = 6), nanoembolic (n = 5), immune (n = 2), or other novel (n = 1) agents. CONCLUSIONS: Animal studies show preferential tumor uptake of anticancer agent, good hepatic/systemic tolerance, high tumor response, and enhanced survival after ethiodized oil-based LRT.

The value of paradoxical uptake of hepatocellular carcinoma on the hepatobiliary phase of gadoxetic acid-enhanced liver magnetic resonance imaging for the prediction of lipiodol uptake after transcatheter arterial chemoembolization.

PURPOSE: To compare the response to transcatheter arterial chemoembolization (TACE) between hepatocellular carcinoma (HCC) with paradoxical uptake on the hepatobiliary phase (HBP) (HCCpara) and HCC with defect on the HBP (HCCdef), and to identify some imaging features that can differentiate between two groups. MATERIALS AND METHODS: Ninety-three HCCs from 54 patients who underwent gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) prior to TACE were included. HCCs were classified into two groups according to the signal intensity (SI) on the HBP: HCCpara and HCCdef. Using post-TACE computed tomography (CT) as a reference standard, initial compact lipiodol uptake was assessed and compared between groups. The arterial enhancement ratio (AER), SI ratios of the arterial phase and HBP, and presence of the capsule appearance were compared between groups. After initial response, local tumor recurrence within 6 and 18 months was evaluated based on follow-up CT or MRI. RESULTS: Fifteen HCCpara and 78 HCCdef were included. Compared to HCCdef, HCCpara showed more frequent initial compact lipiodol uptake (p=0.009), larger mean size (p=0.019), lower AER (p=0.005), higher SI ratio of the HBP (p<0.0001), and more frequent capsule appearance (p<0.0001). Local tumor recurrence rate within 6 months was also significantly lower in HCCpara than in HCCdef (p=0.008). CONCLUSION: Despite larger size and lower AER, HCCpara showed more frequent initial compact lipiodol uptake and lower early local recurrence rate after TACE than did HCCdef.

Preparation and Characterization of Hyaluronic Acid-Polycaprolactone Copolymer Micelles for the Drug Delivery of Radioactive Iodine-131 Labeled Lipiodol.

Micelles, with the structure of amphiphilic molecules including a hydrophilic head and a hydrophobic tail, are recently developed as nanocarriers for the delivery of drugs with poor solubility. In addition, micelles have shown many advantages, such as enhanced permeation and retention (EPR) effects, prolonged circulation times, and increased endocytosis through surface modification. In this study, we measured the critical micelle concentrations, diameters, stability, and cytotoxicity and the cell uptake of micelles against hepatic cells with two kinds of hydrophilic materials: PEG-PCL and HA-g-PCL. We used 131I as a radioactive tracer to evaluate the stability, drug delivery, and cell uptake activity of the micelles. The results showed that HA-g-PCL micelles exhibited higher drug encapsulation efficiency and stability in aqueous solutions. In addition, the 131I-lipiodol loaded HA-g-PCL micelles had better affinity and higher cytotoxicity compared to HepG2 cells.

Lipiodol retention pattern assessed by cone beam computed tomography during conventional transarterial chemoembolization of hepatocellular carcinoma: accuracy and correlation with response.

BACKGROUND: To investigate accuracy of intraprocedural cone beam computed tomography (CBCT) compared to fluoroscopy for detection of lipiodol retention pattern during conventional transarterial chemoembolization (cTACE) of hepatocellular carcinoma (HCC) and its correlation with short-term response. METHODS: Between September 2013 and July 2014, 29 patients with HCC underwent chemoembolization of 51 tumors (mean diameter 28.1 mm, range 10.0-136.3 mm). Lipiodol retention pattern was assessed by CBCT at the endpoint of cTACE compared by fluoroscopy. Depending on the pattern of tumor covered by lipiodol three classes were defined: complete (more than 90 %, no peripheral defects), moderate (50-90 %, some with or without peripheral defects), and poor (less than 50 %). Tumor response was assessed by modified Response Evaluation Criteria in Solid Tumors (mRECIST) based on follow-up contrast enhanced (CE) computed tomography (CT) or magnetic resonance imaging (MRI) obtained 4-6 weeks post-cTACE. Correlations between lipiodol retention patterns on CBCT and fluoroscopy as well as tumor response were assessed using multivariate logistic regression. RESULTS: Of 51 hepatic tumors, 40 (78.4 %) had complete response (CR); 8 (15.7 %) had partial response (PR); 1 (2.0 %) had stable disease (SD); and 2 (3.9 %) had progressive disease (PD). The degree of lipiodol retention scored excellent, moderate, and poor, in fluoroscopic images vs CBCT images were 23 (45.1 %) vs 39 (76.5 %), 19 (37.3 %) vs 11 (21.6 %), and 9 (17.6 %) vs 1 (2.0 %), respectively. Lipiodol retention assessment with CBCT (Az = 0.75) is more accurate than fluoroscopy (Az = 0.54) in predicting target tumor response. Other than lipiodol retention pattern assessed with CBCT (p = 0.01), tumor size (p = 0.04) is an independent predictors of CR. CONCLUSION: CBCT is more accurate than fluoroscopy in classification of lipiodol retention pattern in HCC tumors at the time of cTACE. CBCT could be used as a reliable intra precedural monitoring modality of cTACE.

Availability of applying diaphragm matching with the breath-holding technique in stereotactic body radiation therapy for liver tumors.

PURPOSE: Image-guided radiotherapy (IGRT) based on bone matching can produce large target-positioning errors because of expiration breath-hold reproducibility during stereotactic body radiation therapy (SBRT) for liver tumors. Therefore, the feasibility of diaphragm-based 3D image matching between planning computed tomography (CT) and pretreatment cone-beam CT was investigated. METHODS: In 59 liver SBRT cases, Lipiodol uptake after transarterial chemoembolization was defined as a tumor marker. Further, the relative isocenter coordinate that was obtained by Lipiodol matching was defined as the reference coordinate. The distance between the relative isocenter coordinate and reference coordinate, which was obtained from diaphragm matching and bone matching techniques, was defined as the target positioning error. Furthermore, the target positioning error between liver matching and Lipiodol matching was evaluated. RESULTS: The positioning errors in all directions by the diaphragm matching were significantly smaller than those obtained by using by the bone matching technique (p < 0.05). Further, the positioning errors in the A-P and C-C directions that were obtained by using liver matching were significantly smaller than those obtained by using bone matching (p < 0.05). The estimated PTV margins calculated by the formula proposed by van Herk for diaphragm matching, liver matching, and bone matching were 5.0 mm, 5.0 mm, and 11.6 mm in the C-C direction; 3.6 mm, 2.4 mm, and 6.9 mm in the A-P direction; and 2.6 mm, 4.1 mm, and 4.6 mm in the L-R direction, respectively. CONCLUSIONS: Diaphragm matching-based IGRT may be an alternative image matching technique for determining liver tumor positions in patients.

Cone-Beam Computed Tomography Correlates with Conventional Helical Computed Tomography in Evaluation of Lipiodol Accumulation in HCC after Chemoembolization.

BACKGROUND & AIMS: The amount of drug-loaded lipiodol in an HCC tumor post-transarterial chemoembolization (TACE) correlates with the risk of local tumor recurrence. Lipiodol enhancement of a tumor on conventional CT, measured in Hounsfield units (HU), can predict tumor response. Here we investigate whether cone-beam CT (CBCT) can also be used to predict tumor response, providing the benefit of being able to optimize the patient's treatment plan intra-procedurally. METHODS: A total of 82 HCC nodules (82 patients), ≤5 cm in diameter, were treated with balloon-occluded TACE using miriplatin between December 2013 and November 2014. For each patient, both CBCT and conventional CT images were obtained post-TACE. The degree of correlation between CBCT and conventional CT was determined by comparing identical regions of interest for each imaging modality using pixel values. RESULTS: The pixel values from conventional CT and CBCT were highly correlated, with a Pearson correlation coefficient of 0.912 (p<0.001). The location of the nodules within the liver did not affect the results; the correlation coefficient was 0.891 (p<0.001) for the left lobe and 0.926 (p<0.001) for the right lobe. The mean pixel value for conventional CT was 439 ± 279 HU, and the mean pixel value for CBCT was 416 ± 311 HU. CONCLUSIONS: CBCT may be used as a substitute for conventional CT to quantitatively evaluate the amount of drug-loaded lipiodol within an HCC nodule and, hence, the efficacy of TACE treatment. The major benefit of using CBCT is the ability to predict the likelihood of local recurrence intra-procedurally, enabling subsequent treatment optimization.

Initial Experience with Balloon-Occluded Trans-catheter Arterial Chemoembolization (B-TACE) for Hepatocellular Carcinoma.

PURPOSE: This study was performed to evaluate the accumulation of lipiodol emulsion (LE) and adverse events during our initial experience of balloon-occluded trans-catheter arterial chemoembolization (B-TACE) for hepatocellular carcinoma (HCC) compared with conventional TACE (C-TACE). METHODS: B-TACE group (50 cases) was compared with C-TACE group (50 cases). The ratio of the LE concentration in the tumor to that in the surrounding embolized liver parenchyma (LE ratio) was calculated after each treatment. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Effects (CTCAE) version 4.0. RESULTS: The LE ratio at the level of subsegmental showed a statistically significant difference between the groups (t test: P < 0.05). Only elevation of alanine aminotransferase was more frequent in the B-TACE group, showing a statistically significant difference (Mann-Whitney test: P < 0.05). While B-TACE caused severe adverse events (liver abscess and infarction) in patients with bile duct dilatation, there was no statistically significant difference in incidence between the groups. Multivariate logistic regression analysis suggested that the significant risk factor for liver abscess/infarction was bile duct dilatation (P < 0.05). CONCLUSION: The LE ratio at the level of subsegmental showed a statistically significant difference between the groups (t test: P < 0.05). B-TACE caused severe adverse events (liver abscess and infarction) in patients with bile duct dilatation.

Differentiation between tuberculosis and leukemia in abdominal and pelvic lymph nodes: evaluation with contrast-enhanced multidetector computed tomography

PURPOSE: To compare the characteristics of tubercular vs. leukemic involvement of abdominopelvic lymph nodes using multidetector computed tomography (CT). MATERIALS AND METHODS: We retrospectively reviewed multidetector computed tomography features including lymph node size, shape, enhancement patterns, and anatomical distribution, in 106 consecutive patients with newly diagnosed, untreated tuberculosis (55 patients; 52%) or leukemia (51 patients; 48%). In patients with leukemia, 32 (62.7%) had chronic lymphocytic leukemia, and 19 (37.3%) had acute leukemias; of these, 10 (19.6%) had acute myeloid leukemia, and 9 (17.6%) had acute lymphocytic leukemia. RESULTS: The lower para-aortic (30.9% for tuberculosis, 63.2% for acute leukemias and 87.5% for chronic lymphocytic leukemia) and inguinal (9.1% for tuberculosis, 57.9% for acute leukemias and 53.1% for chronic lymphocytic leukemia) lymph nodes were involved more frequently in the three types of leukemia than in tuberculosis (both with p <0.017). Tuberculosis showed peripheral enhancement, frequently with a multilocular appearance, in 43 (78.2%) patients, whereas patients with leukemia (78.9% for acute myeloid leukemia and acute lymphocytic leukemia, 87.5% for chronic lymphocytic leukemia) demonstrated predominantly homogeneous enhancement (both with p <0.017). For the diagnosis of tuberculosis, the analysis showed that a peripheral enhancement pattern had a sensitivity of 78.2%, a specificity of 100%, and an accuracy of 88.7%. For the diagnosis of leukemia, the analysis showed that a homogeneous enhancement pattern was associated with a sensitivity of 84.3%, a specificity of 94.5%, and an accuracy of 89.6%. CONCLUSION: Our findings indicate that the anatomical distribution and enhancement patterns of lymphadenopathy seen on multidetector computed tomography are useful for differentiating between untreated tuberculosis and leukemia of the abdominopelvic lymph nodes. .

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.

Using intravoxel incoherent motion (IVIM) MR imaging to predict lipiodol uptake in patients with hepatocellular carcinoma following transcatheter arterial chemoembolization: a preliminary result.

PURPOSE: To assess the usefulness of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) for predicting lipiodol uptake in patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS: The institutional review board approved this study. 44 HCC patients underwent IVIM-DWI and Gd-EOB-DTPA-enhanced MRI prior to TACE. Using post-TACE CT as a reference standard, each HCC was classified into either lipiodol good uptake (LGU) or poor uptake (LPU) group. Apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion coefficient (D*), and perfusion fraction (f) in HCC were calculated. Arterial enhancement ratio (AER) and IVIM parameters were compared between those two groups using the Mann-Whitney U test. RESULTS: Of the 51 HCCs, 37 (72.5%) were LGU group and 14 (27.5%) were LPU group. AER of HCC was significantly higher in LGU than LPU (0.99±0.54 and 0.67±0.45; P=.034). ADC, D, and f values were not significantly different (P=.073, .059, and .196, respectively) between these two groups. D* was significantly elevated in LGU than LPU (48.10±15.33 and 26.75±9.55; P=.001). CONCLUSION: Both AER derived from contrast enhanced MRI and D* values derived from IVIM-DWI for HCC were significantly higher in LGU than in LPU. These parameters would be helpful for predicting the lipiodol uptake.