Accuracy of magnetic resonance imaging in predicting dentate line invasion in low rectal cancer.

PURPOSE: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in predicting dentate line invasion in low rectal cancer. MATERIALS AND METHODS: Eighty-one patients with primary rectal cancer were assessed by dynamic contrast-enhanced MRI. The location of the dentate line was assessed on MRI in 27 patients with upper-mid rectal cancer. Two observers independently evaluated the distance between the distal tumor edge and the MRI-defined dentate line in 54 patients with low rectal cancer, and the imaging and histological findings were compared. RESULTS: The MRI-defined dentate line was 24.0 ± 3.8 mm above the anal verge in patients with upper-mid rectal cancer. The dentate line invasion status agreed with the histological findings in 49/54 (91%) patients (κ = 0.72 [95% CI 0.50-0.95]) for observer 1, and in 51/54 (94%) patients (κ = 0.83 [0.65-1.00]) for observer 2 in patients with low rectal cancer. Interobserver agreement was good (κ = 0.83 [0.65-1.00]). The MRI-derived distance between the distal tumor edge and the dentate line had significant correlation with the histological distance (r = 0.86 for reader 1 and 0.75 for observer 2). CONCLUSION: MRI demonstrates high accuracy in predicting dentate line invasion in low rectal cancer.

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.

Use of a Glass Membrane Pumping Emulsification Device Improves Systemic and Tumor Pharmacokinetics in Rabbit VX2 Liver Tumor in Transarterial Chemoembolization.

PURPOSE: To evaluate the phamacokinetics of epirubicin in conventional transarterial chemoembolization using a developed pumping emulsification device with a microporous glass membrane in VX2 rabbits. MATERIALS AND METHODS: Epirubicin solution (10 mg/mL) was mixed with ethiodized oil (1:2 ratio) using the device or 3-way stopcock. Forty-eight rabbits with VX2 liver tumor implanted 2 weeks prior to transarterial chemoembolization were divided into 2 groups: a device group (n = 24) and a 3-way-stopcock group (n = 24). Next, 0.5 mL of emulsion was injected into the hepatic artery, followed by embolization using 100-300-µm microspheres. The serum epirubicin concentrations (immediately after, 5 minutes after, and 10 minutes after) and the tumor epirubicin concentrations (20 minutes after and 48 hours after) were measured after transarterial chemoembolization. Histopathologic evaluation was performed with a fluorescence microscope. RESULTS: The area under the curve and maximum concentrations of epirubicin in plasma were 0.45 ± 0.18 µg min/mL and 0.13 ± 0.06 µg/mL, respectively, in the device group and 0.71 ± 0.45 µg min/mL and 0.22 ± 0.17 µg/mL, respectively, in the 3-way-stopcock group (P = .013 and P = .021, respectively). The mean epirubicin concentrations in VX2 tumors at 48 hours in the device group and the 3-way-stopcock group were 13.7 ± 6.71 and 7.72 ± 3.26 µg/g tissue, respectively (P = .013). The tumor necrosis ratios at 48 hours were 62 ± 11% in the device group and 51 ± 13% in the 3-way-stopcock group (P = .039). CONCLUSIONS: Conventional transarterial chemoembolization using the pumping emulsification device significantly improved the pharmacokinetics of epirubicin compared to the current standard technique using a 3-way stopcock.

Improved Local Tumor Control and Survival Rates by Obtaining a 3D-Safety Margin in Superselective Transarterial Chemoembolization for Small Hepatocellular Carcinoma.

OBJECTIVE: To investigate technical factors affecting local tumor control of small hepatocellular carcinoma (HCC) treated by superselective conventional transarterial chemoembolization (cTACE) using lipiodol and to compare prognoses between groups with and without these factors. MATERIALS AND METHODS: Sixty-three consecutive patients with 73 HCC nodules (diameter, 1-3 cm) treated by cTACE were retrospectively analyzed. A positive or a negative 3D-safety margin was defined as a ≥ 1-mm area of lipiodol accumulation or as a diameter of lipiodol accumulation < 1 mm in liver parenchyma surrounding the tumor using plain CT images obtained within a week after TACE. Uni- and multivariate analyses were performed to identify technical factors determining local tumor control rate. Subgroup analysis of survival rates in treatment-naïve patients was performed according to the detected factors. RESULTS: In univariate analyses, three-dimensional (3D)-safety margin and portal vein visualization were associated with local tumor control rates. In multivariate analysis, only positive 3D-safety margin remained a significant contributor (p = 0.001). Two-year cumulative local disease-free survival rates with positive and negative 3D-safety margin were 82.8% and 19.3%, respectively (p = 0.001). In subgroup survival analysis of the 36 newly diagnosed patients, the 1-, 2-, 3-, 4-, and 5-year cumulative OS rates for patients with and without positive margins were 100% versus 100%, 96.4% versus 75.0%, 81.8% versus 62.5%, 74.4% versus 41.7%, and 47.0% versus 0%, respectively (median survival time; 57.6 months vs. 37.1, p = 0.047). CONCLUSION: Obtaining a 3D-safety margin can suppress local tumor recurrence and prolong survival in superselective cTACE for small HCC.

Selective TACE with irinotecan-loaded 40 µm microspheres and FOLFIRI for colorectal liver metastases: phase I dose escalation pharmacokinetic study.

BACKGROUND: Efficacy of treatments for colorectal liver metastases after failure of first-line chemotherapy is limited. The aim of this study was to prospectively evaluate the feasibility, tolerability, and pharmacokinetics of selective transarterial chemoembolization (TACE) with irinotecan-loaded 40 µm microspheres combined with systemic FOLFIRI for colorectal liver metastases refractory to oxaliplatin regimen. METHODS: The dose escalation study was conducted in three patient groups with different amounts of irinotecan loaded (50, 75 and 100 mg per mL-microspheres). Selective catheterization was performed to embolize subsegments or segments of located tumors using TACE navigation system. FOLFIRI was administrated 7 days after TACE. Plasma concentration was measured before and time points after administration. RESULTS: Nine patients successfully underwent a total of 22 TACE procedures. Dose-limiting toxicity did not appear at any level. The overall response rate was 55.6%. The median progression free and overall survival were 8.1 and 18.2 months, respectively. The AUC and Cmax of plasma SN-38 per 1 mg injected irinotecan dose were significantly higher in irinotecan-loaded microspheres compared with FOLFIRI (P = 0.009 and P <  0.001, respectively). CONCLUSION: Selective TACE using 40 µm irinotecan-loaded microspheres combined with systemic FOLFIRI was feasible and safe even when a high dose of irinotecan was loaded. Irinotecan-loaded microspheres resulted in a higher plasma concentration and AUC of SN-38 than treatment with FOLFIRI. Further large scale trials to evaluate the efficacy are mandatory. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN) Clinical Trials Registry, Registration number; UMIN000015367 ; Registered date; 08,10,2014.

Safety and Prognosis of Transarterial Chemoembolization for Octogenarians with Hepatocellular Carcinoma.

PURPOSE: The global population of the aged is escalating. The need of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) in patients older than 80 years is on the rise. The aim of this study was to retrospectively evaluate the safety and the prognosis of TACE in octogenarians with HCC. MATERIALS AND METHODS: From January 2007 to January 2018, 86 octogenarians with HCC initially treated with TACE, who were treatment naïve or had a recurrence after surgery and/or radiofrequency ablation, were enrolled in this study. The adverse events were evaluated. The overall survival (OS) after TACE and causes of death were investigated. The prognostic factors for OS were analyzed using Cox proportional hazard models. RESULTS: Grade 4 adverse events (according to the Common Terminology Criteria for Adverse Event version 4.0) of AST, ALT and tumor rupture were found in 8, 4 and 1 patients, respectively. There were no treatment-related deaths. The 1-, 3- and 5-year overall survival rates were 84.1%, 61.1% and 27.6%, respectively. The overall median survival time was 38.3 months (HR 2.854, 95% CI 32.7-43.8). 56.9% causes of death were HCC or liver dysfunction. Multivariate analysis revealed that performance status (ECOG: 0) was an independent prognostic significant factor (95% CI 1.103-4.573; P = .026). CONCLUSIONS: TACE is safe and could improve survival of octogenarians with HCC. Performance status is an important prognosis factor predicting the OS.

Development of Repeatable Microcatheter Access Port for Intra-arterial Therapy of Liver Cancer.

PURPOSE: To develop an implantable port in which a microcatheter can be inserted for a combination therapy of repeated transarterial chemoembolization (TACE) and hepatic arterial infusion chemotherapy (HAIC) for advanced liver cancer. MATERIALS AND METHODS: The design of a currently used implantable port was modified. A funnel part was constructed in the port. The septum was punctured by a 20-gauge indwelling needle, and 2.0-Fr non-tapered microcatheter was inserted into the port. In the in vitro studies, the advance of a microcatheter out of the funnel part was evaluated via seven different septum puncture sites. A 5-Fr indwelling catheter connected to the port was placed in a vascular model, and a microcatheter catheterization was evaluated. In an in vivo study, the port-catheter system was implanted in the hepatic artery in a pig. A microcatheter was percutaneously inserted through the port into the hepatic arterial branches, and embolization was performed. RESULTS: In the in vitro studies, the microcatheter was smoothly advanced out of the port and catheterizations into the hepatic arteries were successful via all septum puncture sites. In the in vivo study, repeated selective embolization through the port was successfully conducted on 7, 14 and 21 days after the implantation. CONCLUSION: The developed implantable port can be used for repeated catheter insertion into the hepatic artery. The combination of repeated TACE and HAIC could be possible using this device.

Superabsorbent Polymer Microspheres Prepared with Hypertonic Saline to Reduce Microsphere Expansion.

PURPOSE: To analyze size changes of superabsorbent polymer (SAP) microspheres with the reduced expansion technique, and to evaluate pharmacological advantages of transarterial chemoembolization using cisplatin-loaded SAP microspheres with the reduced expansion technique. MATERIALS AND METHODS: In an in vitro study, diluted contrast materials containing different concentrations of sodium ions were examined to expand SAP microspheres and determined the reduced expansion technique. Size distributions of cisplatin-loaded SAP microspheres were analyzed. In an in vivo study, TACE was performed using cisplatin-loaded SAP microspheres with the reduced expansion and control techniques in 18 VX2 rabbits. RESULTS: The degree of expansion was reduced to the greatest extent by using a mixture of non-ionic contrast material and 10% NaCl at a 4:1 ratio. The mean diameter of the reduced expansion of cisplatin-loaded SAP microspheres was 188.4 µm, while that of the control expansion was 404.9 µm. The plasma platinum concentrations of the reduced expansion group at 5 min after TACE were significantly higher than those of the control expansion group (2.19 ± 0.77 vs. 0.75 ± 0.08 µg/mL, P = .01). The tumor platinum concentrations of the reduced expansion group at 1 h were significantly higher than those of the control expansion group (10.76 ± 2.57 vs. 1.57 ± 0.14 µg/g, P = .044). CONCLUSION: The expanding level of SAP microspheres can be reduced by using hypertonic saline. Cisplatin-loaded SAP microspheres with the reduced expansion technique have the advantages of achieving higher cisplatin tissue concentration in TACE for liver tumors.

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.

Intraarterial Therapy Using Micellar Nanoparticles Incorporating SN-38 in a Rabbit Liver Tumor Model.

PURPOSE: To evaluate the pharmacokinetics of intraarterial (IA) administration of micellar nanoparticles incorporating SN-38 injection compared with intravenous (IV) administration in a rabbit liver tumor model. MATERIALS AND METHODS: In this animal care committee-approved study, 18 rabbits (mean weight, 3.89 kg; range, 3.20-4.70 kg) with VX2 liver tumors were divided into two groups (IA and IV). Micellar nanoparticles incorporating SN-38 (30 mg/kg) were injected through the left hepatic artery in the IA group and the right femoral vein in the IV group. NK012 and free SN-38 in the plasma, liver parenchyma, and tumors were measured within 24 hours. Histologic examinations were conducted at 2 and 24 hours. RESULTS: There were no significant differences in the serum area under the concentration-time curve (0-24 h) for free SN-38, at 1,500 and 1,310 µg∙min/mL in the IA and IV groups, respectively (P = .152). The IA group showed significantly higher free SN-38 concentrations in tumor tissues at all time points compared with the IV group (P = .002 at 3 min, P = .011 at 2 h, and P = .047 at 24 h). Histologic findings showed that significantly higher tumor necrosis ratios were observed in the IA group compared with the IV group at 24 hours (P = .028). CONCLUSIONS: Micellar nanoparticles could be a promising IA drug delivery system to achieve high tumor tissue concentrations of SN-38.

Pharmacokinetics and Histopathological Findings of Chemoembolization Using Cisplatin Powder Mixed with Degradable Starch Microspheres in a Rabbit Liver Tumor Model.

PURPOSE: The purpose of this study is to evaluate the pharmacokinetics and histopathological findings of transarterial chemoembolization (TACE) using cisplatin powder mixed with degradable starch microspheres (DSM) (Cis/DSM-TACE) compared with cisplatin arterial infusion (Cis-AI). MATERIALS AND METHODS: Eighteen rabbits with VX2 liver tumors were divided into two groups: Cis/DSM-TACE (n = 9) and Cis-AI (n = 9) groups. In the Cis/DSM-TACE group, a mixture of cisplatin powder and DSM was injected until stasis of hepatic arterial flow was achieved. In the Cis-AI group, cisplatin solution was infused. RESULTS: The platinum concentrations in VX2 tumors in the Cis/DSM-TACE group at 24 and 72 h were significantly elevated compared with those in the Cis-AI group (P = .016 and .019, respectively). There were no significant differences in the platinum concentrations in plasma. Histopathological examination revealed the presence of several microspheres inside the tumors at 1 h, which completely disappeared at 24 h. Tumor cell apoptosis at 1 h in the Cis/DSM-TACE group was more frequently observed compared with that in the Cis-AI group (P = .006). CONCLUSIONS: TACE using cisplatin powder mixed with DSM provides a higher drug concentration in tumors, thereby achieving stronger antitumor effects compared with arterial infusion of cisplatin solution.

Pancreatic neuroendocrine neoplasm: correlation between computed tomography enhancement patterns and prognostic factors of surgical and endoscopic ultrasound-guided fine-needle aspiration biopsy specimens.

PURPOSE: To retrospectively determine whether enhancement patterns in the pancreatic and equilibrium phases of computed tomography (CT) for pancreatic neuroendocrine neoplasms are related to prognostic factors of surgical and endoscopic ultrasound-guided fine-needle aspiration biopsy specimens. METHODS: Twenty-five pancreatic neuroendocrine neoplasms in 22 patients underwent preoperative dynamic CT. Tumors were classified into two groups by enhancement patterns on preoperative CT. A washout pattern was defined as peak enhancement in the pancreatic phase with washout of at least 60 Hounsfield units in the equilibrium phase. Group 1 comprised tumors showing a washout pattern in more than half of tumor and Group 2 comprised tumors showing a washout pattern in less than half of the tumor. The Ki-67 index and the presence of vascular invasion were evaluated in surgical specimens. The Ki-67 index from biopsy specimens was compared with that from surgical specimens. RESULTS: There were 12 surgical specimens in Group 1 and 13 in Group 2. Group 2 showed significant correlations with larger Ki-67 indices (p < 0.05) and positive vascular invasion (p < 0.05). The Ki-67 index discrepancy between biopsy and surgical specimens of Group 2 was significantly greater than that of Group 1 (p < 0.05). CONCLUSIONS: Pancreatic neuroendocrine neoplasms in which less than half of the tumor showed a washout pattern were correlated with poor prognostic factors. Analysis of enhancement patterns may provide predictive information about whether endoscopic ultrasound-guided fine-needle aspiration biopsy is reliable for the assessment of Ki-67 index.