Targeting of different ethiodized oil-doxorubicin mixtures to hypovascular hepatic metastases with intraarterial and intraportal injections

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 (AUC_0−∞) 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.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

MoS2 nanosheets encapsulated in sodium alginate microcapsules as microwave embolization agents for large orthotopic transplantation tumor therapy

In recent years, it is prevalent to treat various kinds of the tumors through microwave ablation method. However, it is still very difficult to ablate large tumors by the traditional microwave ablation therapy. In this work, an effective microwave embolization agent designed by encapsulating molybdenum sulfide nanosheets in the sodium alginate microcapsules, denoted as MSMCs, was prepared for the effective therapy of large tumor. The toxicity evaluation showed that MSMC had a good biocompatibility in vitro. The in vitro and in vivo experiments demonstrated that the MSMC was an excellent embolic and microwave susceptible agent that could be used for dual-enhanced microwave ablation therapy. As such, the MSMC showed excellent tumor therapeutic effect with 5 times larger ablation zone observed by magnetic resonance (MR) imaging than the microwave alone after 3 days treating. Besides, the tumor is nearly completely ablated and can not be recurrent due to the persistent hyperthermia. Moreover, MSMCs have a good biocompatibility and can be degraded and cleared from the body. It is believed that the MSMC is demonstrated to be a promising multifunctional theranostic agent used for treating the larger tumor via the synergistic therapy of enhanced microwave ablation and transcatheter arterial embolization (TAE).

Use of Lipiodol as a drug-delivery system for transcatheter arterial chemoembolization of hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) remains a major public health problem. Transarterial chemoembolization (TACE) is recognized as the standard of care for patients with unresectable, asymptomatic, noninvasive and multinodular HCC. This procedure is based on percutaneous administration of a cytotoxic drug emulsified with Lipiodol followed by embolization of the tumour-feeding arteries. The standard procedure involves Lipiodol, an oily contrast medium which consists of a mixture of long-chain di-iodinated ethyl esters of poppy seed fatty acids. The aim of this review is to discuss the physical properties, tumour uptake behaviour and drug delivery effects of Lipiodol, the parameters influencing tumour uptake and future prospects. Lipiodol has a unique place in TACE as it combines three specific characteristics: drug delivery, transient and plastic embolization and radiopacity properties. Substantial heterogeneity in the physicochemical characteristics of Lipiodol/cytotoxic agent emulsions might reduce the efficacy of this procedure and justifies the current interest in Lipiodol for drug delivery.

The expanding role of interventional radiology in the supportive care of the oncology patient: From diagnosis to therapy

Interventional radiology (IR) plays an increasing role in the supportive care of the cancer patient from the placement of catheters to treating the offending tumor via image-guided methods. These methods entail the use of both local and regional means, with thermal ablative technology comprising the former and intra-arterial embolization with radioactive particles the latter. Direct placement of the radiofrequency or cryotherapy probes into tumors that are accessible using computed tomography (CT), ultrasound, or magnetic resonance imaging (MRI) guidance provides reliable symptomatic relief of single or multiple tumors in liver, kidney, lung, bone, or soft tissue. Combined with systemic chemotherapy, these techniques increase patient survival. Intra-arterial delivery of radioactive particles to unresectable tumors both provides symptomatic relief and extends survival when combined with current systemic chemotherapy. These new approaches allow IR to provide crucial therapy for cancer patients.

Hepatic perfusion changes in mice livers with developing colorectal cancer metastases

PURPOSE

To evaluate whether intrahepatic flow alterations occur during formation of hepatic colorectal cancer metastases and to identify possible causes of these alterations.

MATERIALS AND METHODS

Intravital imaging of exteriorized livers was performed in 72 live mice. Three groups of mice were studied: a sham-operated control group (n = 24), a group with nonmetastasizing subcutaneous gliomas (n = 24), and a group with developing hepatic CX-1 colon cancer metastases (n = 24). Microvascular flow parameters, leukocyte-endothelial interactions, and wall shear stress were directly measured in hepatic sinusoids and postsinusoidal venules at 2-day intervals prior to and during the development of metastases. The Kruskal-Wallis test was used initially to test for overall equality of medians in each data group. Single posttest comparisons of independent samples were performed with the Mann-Whitney test, with an overall statistical significance of .05.

RESULTS

Prior to the development of visible colorectal cancer metastases, significant (P <.05) reductions occurred in sinusoidal and postsinusoidal flow and wall shear rates, coupled with increased leukocyte rolling and adherence. With tumor growth, flow was further compromised in 92% of tumors larger than 0.5 mm in diameter by extrinsic compression of sinusoids and portal venules and narrowing caused by adherent leukocytes.

CONCLUSION

Significant intrahepatic flow alterations occur in mouse livers prior to growth of visible metastases and provide a rational explanation for elevation in the Doppler perfusion index that occurs prior to tumor formation.

Hepatic colon cancer metastases in mice: dynamic in vivo correlation with hypoechoic rims visible at US

PURPOSE

To use videomicroscopy of tumor-bearing livers of live mice to depict tumors directly to determine the exact nature of rims seen on corresponding ultrasonographic (US) scans.

MATERIALS AND METHODS

Seventy-six hepatic colorectal cancer metastases were studied in exteriorized livers of 18 mice by using intravital microscopy, US, and histologic examination of the same tumors.

RESULTS

Hypoechoic rims correlated with distended sinusoidal spaces in vivo. These spaces surrounded only locally invasive tumors (mean diameter, 0.85 mm) that had obstructed the supplying terminal portal venules. These spaces, containing adherent leukocytes and tumor cells, gave rise to new tumor vasculature. Results of histologic examination of rims (portal inflammation, congested or compressed sinusoids, cell atrophy) correlated with leukocyte endothelial adherence, occluded sinusoids, and new vessel formation in vivo.

CONCLUSION

Unlike results from previous studies, dynamic in vivo observations of peritumoral rims demonstrated distended sinusoidal spaces giving rise to new tumor-penetrating vessels. These sinusoids arose around locally invasive tumors and were associated with more advanced intrahepatic disease. These dynamic observations provide a pathophysiologic explanation for previous histologic correlates of peritumoral rims.

Modification of arterial and portal hemodynamics after injection of iodized oils and different emulsions of iodized oils in the hepatic artery: an experimental study

PURPOSE

A strong embolic effect of iodized oil/drug mixtures injected in the hepatic artery appeared to be an efficient way of prolonging the contact time between drugs and tumor tissue. Therefore, the authors evaluated arterial and portal embolic effects after hepatic intra-arterial injection of iodized oils and various emulsions of iodized oil.

MATERIALS AND METHODS

Twenty-five pigs were monitored for the Doppler resistance index (DRI) in the hepatic artery and wedge hepatic vein pressure (WHVP) during 1 hour after injection of pure iodized oil, ultra-fluid or fluid, and four different emulsions of iodized oil ultra-fluid, into the hepatic artery.

RESULTS

Mean area under the curve (AUC) values of DRI increases varied from 20.3 to 24.2 after injection of pure iodized oils or water-in-oil emulsions, and were 13.2 for large-droplet oil-in-water emulsion and 8.2 for small-droplet oil-in-water emulsion. Mean AUC values of WHVP increases varied from 151.6 to 195.6 after injection of pure iodized oils or water-in-oil emulsions, and were 105.5 for large-droplet oil-in-water emulsion and 8.5 for small-droplet oil-in-water emulsion. There was a significant difference in DRI and WHVP modifications between small-droplet oil-in-water emulsions and all other products (P = .001), between the two oil-in-water emulsions and the two water-in-oil emulsions (P = .004), and between the two oil-in-water emulsions and pure iodized oils (P = .002).

CONCLUSION

After hepatic intra-arterial injection, water-in-oil emulsions and pure iodized oils provided a stronger embolic effect than oil-in-water emulsion, both in the hepatic artery and in the portal vein.