Pharmacokinetics and toxicity of intraarterial adriamycin for hepatocellular carcinoma: effect of coadministration of lipiodol

Efficacy, mechanism, and safety of melatonin-loaded on thermosensitive nanogels for rabbit VX2 tumor embolization: A novel design

Transarterial chemoembolization (TACE) has been widely used for hepatocellular carcinoma. Reducing hypoxia in the tumor microenvironment after TACE remains a challenge as tumor progression is common in post-TACE patients due to the hypoxic tumor microenvironment. In this study, melatonin loaded on p(N-isopropyl-acrylamide-co-butyl methylacrylate) (PIB-M) was used for tumor embolism. Two types of human hepatoma cell lines were used to explore the mechanism by which melatonin prevents the growth and metastasis of cancer cells in vitro. A VX2 rabbit tumor model was used to evaluate the efficacy, mechanism, and safety of PIB-M in vivo. We found that under hypoxic condition, melatonin could inhibit tumor cell proliferation and migration by targeting hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGF-A) in vitro. In vivo, PIB-M inhibited tumor growth and metastasis in rabbit VX2 tumors by promoting apoptosis of tumor cells and targeting related angiogenic proteins and vascular permeability proteins. A high concentration of melatonin in the PIB-M group could be maintained in tumor tissue for 72 h after embolization. The liver and kidney functions were most damaged on the first day but recovered to normal on the seventh day after embolization in the PIB-M group. This novel method may open avenues for reduction of tumor growth and metastasis after TACE and is efficacy and safety, which may be used for treatment for other solid tumors and clinical translation.

Multidisciplinary Taiwan consensus for the use of conventional TACE in hepatocellular carcinoma treatment

Developed in early 1980s, transarterial chemoembolization (TACE) with Lipiodol was adopted globally after large-scale randomized control trials and meta-analyses proving its effectiveness were completed. Also known as "conventional TACE" (cTACE), TACE is currently the first-line treatment for patients with unresectable intermediate stage hepatocellular carcinoma (HCC) and delivers both ischemic and cytotoxic effects to targeted tumors. Although new technology and clinical studies have contributed to a more comprehensive understanding of when and how to apply this widely-adopted therapeutic modality, some of these new findings and techniques have yet to be incorporated into a guideline appropriate for Taiwan. In addition, differences in the underlying liver pathologies and treatment practices for transcatheter embolization between Taiwan and other Asian or Western populations have not been adequately addressed, with significant variations in the cTACE protocols adopted in different parts of the world. These mainly revolve around the amount and type of chemotherapeutic agents used, the type of embolic materials, reliance on Lipiodol, and the degree of selectiveness in catheter positioning. Subsequently, interpreting and comparing results obtained from different centers in a systematic fashion remain difficult, even for experienced practitioners. To address these concerns, we convened a panel of experts specializing in different aspects of HCC treatment to devise modernized recommendations that reflect recent clinical experiences, as well as cTACE protocols which are tailored for use in Taiwan. The conclusions of this expert panel are described herein.

Sorafenib plus drug-eluting bead transarterial chemoembolization for early intrahepatic stage-progressed advanced hepatocellular carcinoma refractory to conventional transarterial chemoembolization

PURPOSE

To investigate the effectiveness and safety of the combination of sorafenib and drug-eluting bead transarterial chemoembolization (DEB-TACE) in the treatment of early intrahepatic stage-progressed advanced hepatocellular carcinoma (ISPA-HCC).

METHODS

This study was approved by the ethics committees of six tertiary medical centers in China. Between October 2017 and October 2020, 213 patients with advanced HCC received either sorafenib combined with on-demand DEB-TACE (DTS group, n = 103) or sorafenib monotherapy (S group, n = 110). Overall survival (OS), time to progression (TTP), local tumor response, and adverse events (AEs) were compared between the two groups.

RESULTS

The incidences of nause/vomiting, abdonimal pain, hyperbilirubinemia, fever and ALT/AST increasing were higher in the DTS group. The post-treatment partial response, objective response, and disease control rates were significantly higher in the DTS group than in the S group (51.5% vs. 23.6%; 56.3% vs. 25.5%; 77.7% vs. 56.4%, respectively). The median OS was significantly longer in the DTS group than in the S group [16.3 vs. 10.0 months; hazard ratio (HR) = 0.43; P < 0.001], as was the TTP (6.7 vs. 4.3 months; HR = 0.60; P = 0.001). In the DTS group, patients who received ≥ 2 sessions of DEB-TACE benefited more than those who received two sessions of DEB-TACE. Multivariate analysis revealed that the α-fetoprotein level and treatment allocation were independent predictors of OS and TTP.

CONCLUSION

The combination of sorafenib and DEB-TACE is safe and effective for the treatment of early ISPA-HCC.

Conventional versus drug-eluting embolic transarterial chemoembolization with doxorubicin: comparative drug delivery, pharmacokinetics, and treatment response in a rabbit VX2 tumor model

The purpose of this study was to compare intra-tumoral drug delivery, pharmacokinetics, and treatment response after doxorubicin (DOX) conventional (c-) versus drug-eluting embolic (DEE-) transarterial chemoembolization (TACE) in a rabbit VX2 liver tumor model. Twenty-four rabbits with solitary liver tumors underwent c-TACE (n = 12) (1:2 water-in-oil emulsion, 0.6 mL volume, 2 mg DOX) or DEE-TACE (n = 12) (130,000 70-150 µm 2 mg DOX-loaded microspheres). Systemic, intra-tumoral, and liver DOX levels were measured using mass spectrometry up to 7-day post-procedure. Intra-tumoral DOX distribution was quantified using fluorescence imaging. Percent tumor necrosis was quantified by a pathologist blinded to treatment group. Lobar TACE was successfully performed in all cases. Peak concentration (C_MAX, µg/mL) for plasma, tumor tissue, and liver were 0.666, 4.232, and 0.270 for c-TACE versus 0.103, 8.988, and 0.610 for DEE-TACE. Area under the concentration versus time curve (AUC, µg/mL ∗ min) for plasma, tumor tissue, and liver were 18.3, 27,078.8, and 1339.1 for c-TACE versus 16.4, 26,204.8, and 1969.6 for DEE-TACE. A single dose of intra-tumoral DOX maintained cytotoxic levels through 7-day post-procedure for both TACE varieties, with a half-life of 1.8 (c-TACE) and 0.8 (DEE-TACE) days. Tumor-to-normal liver DOX ratio was high (c-TACE, 20.2; DEE-TACE, 13.3). c-TACE achieved significantly higher DOX coverage of tumor vs. DEE-TACE (10.8% vs. 2.3%; P = 0.003). Percent tumor necrosis was similar (39% vs. 37%; P = 0.806). In conclusion, in a rabbit VX2 liver tumor model, both c-TACE and DEE-TACE achieved tumoricidal intra-tumoral DOX levels and high tumor-to-normal liver drug ratios, though c-TACE resulted in significantly greater tumor coverage.

Development and Validation of Sorafenib-eluting Microspheres to Enhance Therapeutic Efficacy of Transcatheter Arterial Chemoembolization in a Rat Model of Hepatocellular Carcinoma

Purpose

To validate the therapeutic efficacy of sorafenib-eluting embolic microspheres (SOR-EMs) used in combination with transarterial chemoembolization (TACE) for treatment of hepatocellular carcinoma (HCC) in a preclinical animal model.

Materials and Methods

SOR-EMs were prepared with poly(d,l-lactide-co-glycolide), iron oxide nanoparticles, and sorafenib. The morphology of the prepared SOR-EMs was confirmed by using optical microscopy. Drug release from the SOR-EMs was quantified in vitro by using high-performance liquid chromatography. In an orthotopic rat model of HCC, embolic doxorubicin-Lipiodol (ethiodized oil) emulsion (DLE) and SOR-EMs were sequentially injected into the hepatic artery of the rats: The rats in group 1 were injected with DLE; group 2 was injected with DLE plus unloaded embolic microspheres (DLE + EM); group 3, with DLE plus SOR-EMs (DLE + SOR-EM); and group 4, with saline solution. The SOR-EM and tumor size changes in each group (of six rats each) over time were measured by using MRI. Tissues were assessed by using immunohistochemistry, with hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated dUTP (2'-deoxyuridine 5'-triphosphate) nick-end labeling staining used for dead cells and CD34 staining used for new microvessel formation.

Results

The SOR-EMs were a mean size of 6.6 μm ± 2.3 (standard deviation) and showed 53.7% ± 8.3 sorafenib loading efficiency with T2-weighted MRI capability. In the HCC rat model, the intra-arterially injected SOR-EMs were successfully monitored by using MRI. The DLE + SOR-EM-treated rats showed a superior tumor growth-inhibitory effect compared with the rats treated with DLE only (P < .05). Immunohistochemical assessment of tissue specimens showed that compared with the other treatment groups, the DLE + SOR-EM treatment group had the lowest number of microvessels, as quantified by using the percentage of CD34-positive stained area (P < .01 for all comparisons).

Conclusion

In a preclinical rat HCC model, SOR-EMs used in combination with DLE TACE were effective in treating HCC.Keywords: Chemoembolization, Experimental Investigations, Laboratory Tests, Liver, Technology Assessment Supplemental material is available for this article. © RSNA, 2021See also the commentary by Yamada and Gayed in this issue.

Transarterial Chemoembolization Using 100-μm Drug-Eluting Microspheres in Patients with Hepatocellular Carcinoma: A Prospective Study and Midterm Follow-up

PURPOSE

The purpose of this study was to assess the safety and efficacy of drug-eluting embolic (DEE) transarterial chemoembolization for hepatocellular carcinoma (HCC) in patients who are ineligible for curative treatment, using doxorubicin-loaded Tandem (Varian Medical) microspheres.

MATERIALS AND METHODS

Between October 2015 and December 2017, 98 patients with unresectable HCC (69 males, 29 females; mean age, 60.5 ± 10.0 years of age; and American Joint Committee on Cancer [AJCC] stage ≦T3a) treated with DEE transarterial chemoembolization using 100-μm doxorubicin-loaded microspheres were enrolled prospectively. All studies were reviewed and approved by the Institutional Review Board of Chang Gung Memorial Hospital. Dynamic contrast-enhanced computed tomography or magnetic resonance imaging 1 month after treatment was used for tumor response assessment according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Outcomes included overall survival (OS), progression-free survival (PFS), and downstaging profile.

RESULTS

Median follow-up was 21.2 months. At follow-up examinations at 0.5-, 1-, 1.5- and 2.5-year follow-up, OS rates were 93.8%, 89.5%, 79.4%, and 77.0%, respectively. Complete response (CR), partial response, stable disease, and progressive disease were noted in 50 (51.0%), 23 (23.5%), 18 (18.4%), and 7 (7.1%) patients, respectively, with 93.9% disease control rate and 74.5% objective response rate. Mean OS was 28.7 months, and mean PFS was 19.6 months. Number of nodules >3, bilobar disease, larger tumor, and higher AJCC stage correlated with worse CR. No serious adverse events occurred after DEE transarterial chemoembolization. Successful downstage rate was 73.3% (22 of 30) and number of nodules predicting successful downstaging was 7 nodules (cutoff).

CONCLUSIONS

Tandem DEE transarterial chemoembolization provides safe and effective treatment for HCC and a bridge or downstage therapy for liver transplantation.

Handling and performance characteristics of a new small caliber radiopaque embolic microsphere

The in vitro and in vivo handling and performance characteristics of a small caliber radiopaque embolic microsphere, 40–90 μm DC Bead LUMI™ (LUMI40‐90), were studied. Microsphere drug loading and elution and effects on size, suspension, and microcatheter delivery were evaluated using established in vitro methodologies. In vivo evaluations of vascular penetration (rabbit renal artery embolization), long‐term biocompatibility and X‐ray imaging properties, pharmacokinetics and local tissue effects of both doxorubicin (Dox) and irinotecan (Iri) loaded microspheres (swine hepatic artery embolization) were conducted. Compared to 70–150 μm DC Bead LUMI (LUMI70‐150), LUMI40‐90 averaged 70 μm versus 100 μm, which was unchanged upon drug loading. Handling, suspension, and microsphere delivery studies were successfully performed. Dox loading was faster (20 min) and Iri equivalent (<10 min) while drug elution rates were similar. Contrast suspension times were longer with no delivery complications. Vascular penetration was statistically greater (rabbit) with no unexpected adverse safety findings (swine). Microspheres ± drug were visible under X‐ray imaging (CT) at 90 days. Peak plasma drug levels and area under the curve were greater for LUMI40‐90 compared to LUMI70‐150 but comparable to 70–150 μm DC BeadM1™ (DC70‐150). Local tissue effects showed extensive hepatic necrosis for Dox, whereas Iri displayed lower toxicity with more pronounced lobar fibrosis. LUMI40‐90 remains suspended for longer and have greater vessel penetration compared to the other DC Bead LUMI sizes and are similarly highly biocompatible with long‐term visibility under X‐ray imaging. Drug loading is equivalent or faster with pharmacokinetics similar to DC70‐150 for both Dox and Iri.

Interspecies prediction of pharmacokinetics and tissue distribution of doxorubicin by physiologically-based pharmacokinetic modeling

The aim of the study was to develop a physiologically-based pharmacokinetic (PBPK) model to describe and predict whole-body disposition of doxorubicin following intravenous administration. The PBPK model was established using previously published data in mice and included 10 tissue compartments: lungs, heart, brain, muscle, kidneys, pancreas, intestine, liver, spleen, adipose tissue, and plasma. Individual tissues were described by either perfusion-limited or permeability-limited models. All parameters were simultaneously estimated and the final model was able to describe murine data with good precision. The model was used for predicting doxorubicin disposition in rats, rabbits, dogs, and humans using interspecies scaling approaches and was qualified using plasma and tissue observed data. Reasonable prediction of the plasma pharmacokinetics and tissue distribution was achieved across all species. In conclusion, the PBPK model developed based on a rich dataset obtained from mice, was able to reasonably predict the disposition of doxorubicin in other preclinical species and humans. Applicability of the model for special populations, such as patients with hepatic impairment, was also demonstrated. The proposed model will be a valuable tool for optimization of exposure profiles of doxorubicin in human patients.

Effectiveness of drug-eluting bead transarterial chemoembolization versus conventional transarterial chemoembolization for small hepatocellular carcinoma in Child-Pugh class A patients

Background:

This study aimed to compare the therapeutic effectiveness including progression-free survival (PFS), overall survival (OS), and safety of conventional transarterial chemoembolization (cTACE) and drug-eluting bead transarterial chemoembolization (DEB-TACE) in a superselective fashion for the patients with nodular hepatocellular carcinoma (HCC) (n ⩽ 5) and Child–Pugh class A.

Methods:

A total of 198 consecutive patients with nodular HCCs (n ⩽ 5) and Child–Pugh class A liver function who were initially treated with cTACE (n = 125) or DEB-TACE (n = 57) were included retrospectively. The primary endpoint was PFS. Secondary endpoints included time-to-target lesion progression (TTTLP), OS, and safety.

Results:

The median follow up was 62 months (range, 1–87 months). The PFS was significantly longer in the cTACE group than in the DEB-TACE group (median, 18 months versus 7 months; hazard ratio [HR] = 0.658, log-rank p = 0.031), whereas OS was comparable (log-rank p = 0.299). TTTLP was significantly longer in the cTACE group than in the DEB-TACE group (median, 34 months versus 11 months; log-rank p < 0.001). In the stratification analysis based on tumor size, the cTACE group showed significantly longer TTTLP than the DEB-TACE group in the 1.0–2.0 cm and 2.1–3.0 cm subgroups (HR = 0.188, log-rank p < 0.001 and HR = 0.410, p = 0.015, respectively) but not in the 3.1–5.0 cm and 5.1–10.0 cm subgroups (all p > 0.05). Postembolization syndrome occurred more frequently in the cTACE group than in the DEB-TACE group (p = 0.006).

Conclusions:

DEB-TACE is followed by significantly shorter PFS than cTACE in patients with nodular HCCs (n ⩽ 5) and Child–Pugh class A, although OS is comparable. Postembolization syndrome occurs more frequently in cTACE than in DEB-TACE.

Intra-arterial idarubicin_lipiodol without embolisation in hepatocellular carcinoma: The LIDA-B phase I trial

BACKGROUND & AIMS

Idarubicin shows high cytotoxicity against hepatocellular carcinoma (HCC) cells, a high hepatic extraction ratio, and high lipophilicity leading to stable emulsions with lipiodol. A dose-escalation phase I trial of idarubicin_lipiodol (without embolisation) was conducted in patients with cirrhotic HCC to estimate the maximum-tolerated dose (MTD) and to assess the safety, efficacy, and pharmacokinetics of the drug, and the health-related quality of life achieved by patients.

METHODS

Patients underwent two sessions of treatment with a transarterial idarubicin_lipiodol emulsion without embolisation. The idarubicin dose was escalated according to a modified continuous reassessment method. The MTD was defined as the dose closest to that causing dose-limiting toxicity (DLT) in 20% of patients.

RESULTS

A group of 15 patients were enrolled, including one patient at 10 mg, four patients at 15 mg, seven patients at 20 mg, and three patients at 25 mg. Only two patients experienced DLT: oedematous ascitic decompensation and abdominal pain at 20 and 25 mg, respectively. The calculated MTD of idarubicin was 20 mg. The most frequent grade ≥3 adverse events were biological. One month after the second session, the objective response rate was 29% (complete response, 0%; partial response, 29%) based on modified Response Evaluation Criteria In Solid Tumours. The median time to progression was 5.4 months [95% confidence limit (CI) 3.0-14.6 months] and median overall survival was 20.6 months (95% CI 5.7-28.7 months). Pharmacokinetic analysis of idarubicin showed that the mean C_max of idarubicin after intra-arterial injection of the idarubicin-lipiodol emulsion is approximately half the C_max after intravenous administration. Health-related quality of life results confirmed the good safety results associated with use of the drug.

CONCLUSIONS

The MTD of idarubicin was 20 mg after two chemolipiodolisation sessions. Encouraging safety results, and patient responses and survival were observed. A phase II trial has been scheduled.

LAY SUMMARY

There is a need for transarterial regimens that improve the responses and survival of patients with unresectable HCC. In this phase I trial, we showed that two sessions of treatment with a transarterial idarubicin_lipiodol emulsion without embolisation was well tolerated and gave promising efficacy in terms of tumour control and patient survival.

Medical Treatment of Hepatocellular Carcinoma: Any Progress?

Background

Hepatocellular carcinoma (HCC) remains one of the most common neoplasms worldwide. Curative treatment options include liver transplantation or resection. Unfortunately, most patients still have unresectable or untransplantable HCC due to disease extension or comorbid factors and are therefore candidate only for palliative treatments.

Methods

In this review we have analyzed the different medical approaches employed in the treatment of HCC in an attempt to better define their roles.

Results

Palliative medical treatments including systemic chemotherapy, immunotherapy or hormonal manipulation rarely influence survival of the patients. Although a high response rate is often reported with new local therapies such as transcatheter arterial embolization, intraarterial chemotherapy or percutaneous ethanol injection, the real impact of these treatment modalities on patient survival remains to be determined.

Conclusion

One way to improve the diagnosis of HCC patients would be an appropriate approach to evaluate new drugs or treatment modalities. To answer all the open questions, further trials, possibly randomized, should be conducted on a substantial number of patients with homogeneous prognostic factors.

Activity and Tolerability of Courses of Intra-Arterial Chemotherapy Followed by Chemoembolization in Unresectable Hepatocellular Carcinoma

AIMS AND BACKGROUND

We previously reported encouraging response rates and survival with combined intra-arterial (i.a.) chemotherapy and chemoembolization in unresectable hepatocellular carcinoma. We therefore evaluated a new program combining three courses of i.a. chemotherapy with chemoembolization administered every 28 days.

PATIENTS AND METHODS

The treatment regimen consisted of L-leucovorin (100 mg/m2 i.v.), fluorouracil (800 mg/m2 i.a.), and carboplatin (250 mg/m2 i.a.). Chemoembolization with mitoxantrone (10 mg/m2) plus ethiodized oil and gelatin sponge was performed immediately after. The same treatment was given every 28 days for 3 times.

RESULTS

Twenty-eight patients entered the study and were assessable for response and side effects. There were 24 males and 4 females (median age, 68 yrs; range, 42-75). TNM stage was II-III in 20 and IVA in 8; 17 were Child's A and 11 Child's B. Baseline alpha-fetoprotein was elevated in 15, and there was cirrhosis in 23. Twelve patients had a partial response (43%; 95% confidence interval, 24-63%), 13 had stabilization, and 3 progressive disease. Median survival was 16.6 months (range, 2-24). Sixteen patients had grade I-II pain and 14 grade I-II fever.

CONCLUSIONS

Our results indicate that the regimen is safe and well tolerated. Despite 43% objective remissions, our results do not seem better than those obtained with less intensive regimens.

Image-Based Analysis of Tumor Localization After Intra-Arterial Delivery of Technetium-99m-Labeled SPIO Using SPECT/CT and MRI

The aim of this study is to evaluate the localization of ^99mTc-labeled dextran-coated superparamagnetic iron oxide (SPIO) nanoparticles to the liver tumor using image-based analysis. We delivered ^99mTc-SPIO intravenously or intra-arterially (IA) with/without Lipiodol to compare the tumor localization by gamma scintigraphy, single-photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) in a rabbit liver tumor. The gamma and SPECT image-based analysis shows that the uptake ratio of the tumor to the normal liver parenchyma is highest after delivery of ^99mTc-SPIO with Lipiodol IA and that well correlates with the trend of the signal decrease in the liver MRIs. Intra-arterial delivery of SPIO with Lipiodol might be a good drug delivery system targeting the hepatic tumors, as confirmed by image-based analysis.

Chitosan-Based Hydrogel Microparticles for Treatment of Carcinoma in a Rabbit VX2 Liver Tumor Model

PURPOSE

To investigate potential of chitosan hydrogel microparticles (CHI) for treatment of VX2 carcinoma.

MATERIALS AND METHODS

Two weeks after liver VX2 implantation, contrast-enhanced computerized tomographic scanning was conducted. Rabbits (n = 2) with successful tumor growth were treated with different sizes of ^99mTc-labeled CHI (60-80 μm and 100-120 μm) via intra-arterial hepatic catheterization. Liver distribution of ^99mTc-labeled CHI was determined by means of autoradiography, a radiation-based photographic technique. In the next part of this study, therapeutic effectiveness was examined with the use of CHI with the size range of 60-80 μm (n = 11). Tumor growth response and levels of blood liver enzymes were studied at baseline and 1 and 2 weeks after CHI treatment.

RESULTS

Successful tumor growth was confirmed in all rabbits (24/24). Intrahepatic CHI with the size range of 60-80 μm resulted in liver localization in more close proximity to tumor nodule versus 100-120 μm. Baseline tumor volume was 1,909 ± 575 mm³ in animals receiving CHI versus 1,831 ± 249 mm³ in control animals (P = .342). In control animals, tumor volume markedly increased by 1,544 ± 512% at 2 weeks after sham operation versus baseline. In animals receiving CHI, tumor volume remained relatively unchanged (54 ± 6% increase; P = .007 vs control). Levels of blood aspartate transaminase (AST) and alanine transaminase (ALT) in animals receiving CHI increased 1 week after treatment (P = .032 vs control for AST; P = .000 vs control for ALT), but returned to control levels at 2 weeks.

CONCLUSIONS

CHI embolization suppressed tumor growth without appreciable damages in liver function.

Transvascular therapy of Hepatocellular Carcinoma (HCC), status and developments

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Only 30-40% of patients diagnosed with HCC are candidates for curative treatment options. The remaining majority of patients undergo local, regional or systemic palliative therapies. Transvascular therapy of HCC takes advantage of the fact that hypervascularized HCCs receive their main perfusion from the hepatic artery. In this context transvascular therapy describes different therapies: bland embolization (transarterial embolization, TAE), cTACE (conventional transarterial chemoembolization), DEB-TACE (TACE with drug-eluting beads, DEB) and SIRT (selective internal radiation therapy, radioembolization). cTACE is the most common type of transvascular treatment and represents a combination of the intra-arterial use of a chemotherapeutic agent and embolization. There is no standardized regimen for cTACE. It remains unclear whether the intra-arterial application of a chemotherapeutic agent is definitely required, because bland embolization alone using very small spherical particles shows tumor necrosis comparable to cTACE. For DEB-TACE microparticles loaded with a chemotherapeutic drug combine the advantages of cTACE and bland embolization.

New therapeutic approaches to metastatic gastroenteropancreatic neuroendocrine tumors: A glimpse into the future

Neuroendocrine (NE) gastroenteropancreatic tumors are a heterogeneous group of neoplasias arising from neuroendocrine cells of the embryological gut. Their incidence have increased significantly over the past 3 decades probably due to the improvements in imaging and diagnosis. The recent advances in molecular biology have translated into an expansion of therapeutic approaches to these patients. Somatostatin analogs, which initially were approved for control of hormonal syndromes, have recently been proven to inhibit tumor growth. Several new drugs such as antiangiogenics and others targeting mammalian target of rapamycin pathways have been approved to treat progressive pancreatic neuroendocrine tumors (NETs) although their role in non-pancreatic is still controversial. The treatment of NETs requires a coordinated multidisciplinary approach. The management of localized NETs primarily involves surgical resection followed by surveillance. However, the treatment of unresectable and/or metastatic disease may involve a combination of surgical resection, systemic therapy, and liver-directed therapies with the goal of alleviating symptoms of peptide release and controlling tumor growth. This article will review the current therapeutic strategies for metastatic gastroenteropancreatic NETs and will take a glimpse into the future approaches.

Liver and biliary damages following transarterial chemoembolization of hepatocellular carcinoma: comparison between drug-eluting beads and lipiodol emulsion

OBJECTIVES

To compare transarterial chemoembolization (TACE)-related hepatic toxicities of conventional TACE (cTACE) and drug-eluting beads TACE (DEB-TACE) in patients with intermediate-stage hepatocellular carcinoma.

METHODS

In this retrospective study, 151 consecutive patients undergoing cTACE or DEB-TACE and MRI 3-6 weeks before and after therapy were included. Toxicity was assessed on imaging (global hepatic damages (GHD), overall biliary injuries, biliary cast, bile duct dilatation, intrahepatic biloma, portal thrombosis), and clinico-biological follow-ups. Tumour response, time to progression (TTP), and overall survival were assessed. Factors influencing complication rate were identified by generalized equation logistic regression model.

RESULTS

Biliary injuries and intrahepatic biloma incidence were significantly higher following DEB-TACE (p < 0.001). DEB-TACE showed a significant increased risk of GHD (OR: 3.13 [1.74-5.63], p < 0.001) and biliary injuries (OR: 4.53 [2.37-8.67], p < 0.001). A significant relationship was found between baseline prothrombin value and GHD, biliary injuries and intrahepatic biloma (all p < 0.01), and between the dose of chemotherapy and intrahepatic biloma (p = 0.001). Only TTP was significantly shorter following DEB-TACE compared to cTACE (p = 0.025).

CONCLUSIONS

DEB-TACE was associated with increased hepatic toxicities compared to cTACE. GHD, biliary injuries, and intrahepatic biloma were more frequently observed with high baseline prothrombin value, suggesting that cTACE might be more appropriate than DEB-TACE in patients with less advanced cirrhosis.

KEY POINTS

• DEB-TACE demonstrated more therapy-related hepatic locoregional complications compared to cTACE. • TACE-related hepatic locoregional toxicities occurred more frequently with high baseline PT value. • cTACE may be more appropriate in patients with high baseline PT value.

Multimodal Imaging of Nanocomposite Microspheres for Transcatheter Intra-Arterial Drug Delivery to Liver Tumors

A modern multi-functional drug carrier is critically needed to improve the efficacy of image-guided catheter-directed approaches for the treatment of hepatic malignancies. For this purpose, a nanocomposite microsphere platform was developed for selective intra-arterial transcatheter drug delivery to liver tumors. In our study, continuous microfluidic methods were used to fabricate drug-loaded multimodal MRI/CT visible microspheres that included both gold nanorods and magnetic clusters. The resulting hydrophilic, deformable, and non-aggregated microspheres were mono-disperse and roughly 25 um in size. Sustained drug release and strong MRI T₂ and CT contrast effects were achieved with the embedded magnetic nano-clusters and radiopaque gold nanorods. The microspheres were successfully infused through catheters selectively placed within the hepatic artery in rodent models and subsequent distribution in the targeted liver tissues and hepatic tumors confirmed with MRI and CT imaging. These multimodal nanocomposite drug carriers should be ideal for selective intra-arterial catheter-directed administration to liver tumors while permitting MRI/CT visualization for patient-specific confirmation of tumor-targeted delivery.

Preparation of Radiopaque Drug-Eluting Beads for Transcatheter Chemoembolization

PURPOSE

To develop a simple method to produce radiopaque drug-eluting microspheres (drug-eluting beads [DEBs]) that could be incorporated into the current clinical transcatheter arterial chemoembolization workflow and evaluate their performance in vitro and in vivo.

MATERIALS AND METHODS

An ethiodized oil (Lipiodol; Guerbet, Villepinte, France) and ethanol solution was added to a lyophilized 100-300 µm bead before loading with doxorubicin. These radiopaque drug-eluting beads (DEBs; Biocompatibles UK Ltd, Farnham, United Kingdom) were evaluated in vitro for x-ray attenuation, composition, size, drug loading and elution, and correlation between attenuation and doxorubicin concentration. In vivo conspicuity was evaluated in a VX2 tumor model.

RESULTS

Lipiodol was loaded into lyophilized beads using two glass syringes and a three-way stopcock. Maximum bead attenuation was achieved within 30 minutes. X-ray attenuation of radiopaque beads increased linearly (21-867 HU) with the amount of beads (0.4-12.5 vol%; R(2) = 0.9989). Doxorubicin loading efficiency and total amount eluted were similar to DC Bead (Biocompatibles UK Ltd); however, the elution rate was slower for radiopaque DEBs (P < .05). Doxorubicin concentration linearly correlated with x-ray attenuation of radiopaque DEBs (R(2) = 0. 99). Radiopaque DEBs were seen in tumor feeding arteries after administration by fluoroscopy, computed tomography, and micro-computed tomography, and their location was confirmed by histology.

CONCLUSIONS

A simple, rapid method to produce radiopaque DEBs was developed. These radiopaque DEBs provided sufficient conspicuity to be visualized with x-ray imaging techniques.

Improved stability of lipiodol-drug emulsion for transarterial chemoembolisation of hepatocellular carcinoma results in improved pharmacokinetic profile: Proof of concept using idarubicin

OBJECTIVES

To investigate the relationship between the improved stability of an anticancer drug-lipiodol emulsion and pharmacokinetic (PK) profile for transarterial chemoembolisation (TACE) of hepatocellular carcinoma (HCC).

METHODS

The stability of four doxorubicin- or idarubicin-lipiodol emulsions was evaluated over 7 days. PK and clinical data were recorded after TACE with the most stable emulsion in eight unresectable HCC patients, after institutional review board approval.

RESULTS

The most stable emulsion was the one that combined idarubicin and lipiodol (1:2 v:v). At 7 days, the percentages of aqueous, persisting emulsion and oily phases were 50-0-50, 33-0-67, 31-39-30, and 10-90-0 for the doxorubicin-lipiodol (1:1 v:v), doxorubicin-lipiodol (1:2 v:v), idarubicin-lipiodol (1:1 v:v), and the idarubicin-lipiodol (1:2 v:v) emulsion, respectively. After TACE, mean idarubicin Cmax and AUC0-24h were 12.5 ± 9.4 ng/mL and 52 ± 16 ng/mL*h. Within 24 h after injection, 40% of the idarubicin was in the liver, either in vessels, tumours, or hepatocytes. During the 2 months after TACE, no clinical grade >3 adverse events occurred. One complete response, five partial responses, one stabilisation, and one progression were observed at 2 months.

CONCLUSION

This study showed a promising and favourable PK and safety profile for the idarubicin-lipiodol (1:2 v:v) emulsion for TACE.

KEY POINTS

• Transarterial chemoembolisation (TACE) regimens that improve survival in hepatocellular carcinoma are needed. • Improved emulsion stability for TACE resulted in a favourable pharmacokinetic profile. • Preliminary safety and efficacy data for the idarubicin-lipiodol emulsion for TACE were encouraging.

MRI visible drug eluting magnetic microspheres for transcatheter intra-arterial delivery to liver tumors

Magnetic resonance imaging (MRI)-visible amonafide-eluting alginate microspheres were developed for targeted arterial-infusion chemotherapy. These alginate microspheres were synthesized using a highly efficient microfluidic gelation process. The microspheres included magnetic clusters formed by USPIO nanoparticles to permit MRI and a sustained drug-release profile. The biocompatibility, MR imaging properties and amonafide release kinetics of these microspheres were investigated during in vitro studies. A xenograft rodent model was used to demonstrate the feasibility to deliver these microspheres to liver tumors using hepatic transcatheter intra-arterial infusions and potential to visualize the intra-hepatic delivery of these microspheres to both liver tumor and normal tissues with MRI immediately after infusion. This approach offer the potential for catheter-directed drug delivery to liver tumors for reduced systemic toxicity and superior therapeutic outcomes.

Comparison of drug release and pharmacokinetics after transarterial chemoembolization using diverse lipiodol emulsions and drug-eluting beads

In many studies for chemoembolization of hepatocellular carcinoma, the Lipiodol emulsion preparation protocols, especially the mixing steps, were unclear or even unrevealed at all. However, doxorubicin (DOX) release may depend on the composition and volume ratio (Lipiodol to DOX solution) of a Lipiodol emulsion. Therefore, we conducted a preclinical study to compare in-vitro drug release and in-vivo pharmacokinetics of DOX from diverse Lipiodol emulsions and drug-eluting beads (DEBs) and to compare the tumor response in a rabbit VX2 carcinoma model. DOX release profiles of four types of Lipiodol emulsions with different media (normal saline or Pamiray as an iodinated contrast medium), volume ratio (Lipiodol to DOX solution), and DEBs were investigated in-vitro. For the in-vivo study, 15 rabbits bearing VX2 carcinoma in the liver were treated with 4∶1 volume ratio Lipiodol emulsion (group A), 1∶1 volume ratio Lipiodol emulsion (group B), and DEBs (group C) chemoembolization. Blood and tissue sampling was conducted to evaluate DOX concentration in plasma and tissues, histological changes, and liver toxicity. The most stable emulsion was formed with Pamiray (including DOX) at a 4∶1 volume ratio. The AUC value of group A was significantly lower than that of group B (p = 0.003) but comparable to that of group C (p = 0.071). The C_max value of group A was significantly different compared with those of group B (p = 0.004) and C (p = 0.015). The tissue drug concentration in group A was comparable to that in group C (p = 0.251). No viable tumor was detected in rabbits of group A and B. In group C, viable tumor less than 10% was seen in two of the five rabbits. There were no significant differences in liver enzyme levels after the procedure. In conclusion, DOX release and pharmacokinetics of presented emulsion systems depend substantially on their composition. Therefore, Lipiodol emulsion type should be considered when interpreting data and designing new studies dealing with chemoembolization.

Improved drug targeting to liver tumors after intra-arterial delivery using superparamagnetic iron oxide and iodized oil: preclinical study in a rabbit model

PURPOSE

The purpose of this study was to evaluate the feasibility and the therapeutic efficacy of a novel drug-delivery system that uses superparamagnetic iron oxide (SPIO) and iodized oil (IO) to improve the selective intra-arterial (IA) drug delivery to an experimentally induced hepatic tumor.

MATERIALS AND METHODS

This animal study was approved by our institutional animal care and use committee. Fifteen rabbits with hepatic VX2 carcinomas were treated with IA delivery of 4 different agents: doxorubicin alone (group A, n = 3), doxorubicin/IO (group B, n = 3), a doxorubicin/SPIO complex (group C, n = 4), and a doxorubicin/SPIO/IO complex (group D, n = 5). The infused doxorubicin dose was 1 mg for all groups. The serum doxorubicin concentration was measured at 0, 5, 30, 60, and 120 minutes after the delivery. To assess the distribution of the SPIO, magnetic resonance (MR) scans were performed at day 7 after the delivery, when computed tomographic scans were performed in addition to MR in group B and D to assess the distribution of IO. After the completion of follow-up imaging, all the animals were euthanized to measure the intratumoral doxorubicin concentration and to assess tumor viability through pathologic examination.

RESULTS

Groups C and D demonstrated significantly lower MR signal intensities, which inversely corresponded to SPIO deposition, in the tumor areas than did groups A and B. Group D exhibited the lowest serum doxorubicin concentration at all time points up to 180 minutes after the delivery, suggesting minimal passage of doxorubicin into the systemic circulation. The intratumoral doxorubicin concentrations were 72.4 ng/g for group A, 142.0 ng/g for group B, 264.1 ng/g for group C, and 679.6 ng/g for group D. The proportion of viable tumor cells were 65.3% for group A, 1.3% for group B, 17.0% for group C, and 0.1% for group D.

CONCLUSIONS

The drug-delivery system developed using SPIO and IO can result in better drug targeting when it is used for IA delivery to liver cancer. The results of this study warrant further investigation of this potential clinical treatment of advanced liver cancer.

Treatment of intermediate stage hepatocellular carcinoma: a review of intrahepatic doxorubicin drug-delivery systems

The biopharmaceutical properties of doxorubicin delivered via two drug-delivery systems (DDSs) for the palliative treatment of unresectable hepatocellular carcinoma were reviewed with relation to the associated liver and tumor (patho)physiology. These two DDSs, doxorubicin emulsified with Lipiodol® and doxorubicin loaded into DC Bead® are different regarding tumor delivery, release rate, local bioavailability, if and how they can be given repeatedly, biodegradability, length of embolization and safety profile. There have been few direct head-to-head comparisons of these DDSs, and in-depth investigations into their in vitro and in vivo performance is warranted.

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.

A randomised phase II/III trial of 3-weekly cisplatin-based sequential transarterial chemoembolisation vs embolisation alone for hepatocellular carcinoma

Background:

Transarterial chemoembolisation (TACE) has not been shown to be superior to bland embolisation (TAE) for treatment of hepatocellular carcinoma (HCC).

Methods:

We conducted a randomised phase II/III trial in patients with untreated HCC. Patients were randomised to TAE with polyvinyl alcohol (PVA) particles alone or sequential TACE (sTACE) in which cisplatin 50 mg was administered intrarterially 4–6 h before PVA embolisation. Treatment was repeated 3-weekly for up to three treatments. The primary endpoint was overall survival and secondary endpoints were progression-free survival, toxicity and response. Target sample sizes for phase II and III were 80 and 322.

Results:

The trial was terminated at phase II after 86 patients had been randomised. Patients were well matched for prognostic criteria. All three planned treatments were given to 57.1% (TAE) and 56.8% (TACE) patients. Grade 3/4 toxicity occurred in 63.5% and 83.7%, respectively (P=0.019). End-of-treatment RECIST response (CR+PR) was 13.2 and 32.6% (P=0.04) (mRECIST 47.3% and 67.4) and median overall survival and progression-free survival was 17.3 vs 16.3 (P=0.74) months and 7.2 vs 7.5 (P=0.59), respectively.

Conclusion:

Transarterial chemoembolisation according this novel schedule is feasible and associated with a higher response rate than TAE alone. The survival benefit of TACE over TAE remains unproven.

Transarterial chemoembolization with additional cisplatin infusion for hepatocellular carcinoma invading the hepatic vein

PURPOSE

To evaluate retrospectively the efficacy of transarterial chemoembolization in patients with hepatocellular carcinoma (HCC) with hepatic vein invasion by comparing the results of conventional transarterial chemoembolization and modified transarterial chemoembolization.

MATERIALS AND METHODS

From January 2000 to December 2009, 107 patients with HCC and hepatic vein invasion and Child-Pugh class A were treated by transarterial chemoembolization. Modified transarterial chemoembolization (conventional transarterial chemoembolization followed by additional infusion of 50-100 mg of cisplatin) has been undertaken since 2005. Clinical and radiologic data were reviewed and analyzed retrospectively. The overall survival rates were obtained by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

Conventional transarterial chemoembolization was performed in 60 patients, and modified transarterial chemoembolization was performed in 47 patients. No significant differences were observed in major complications between the groups. The median survival was longer in the modified group compared with the conventional group (9.7 mo, 95% confidence interval [CI], 4.3-15.1, vs 6.7 mo, 95% CI, 4.8-8.5; P = .047). By subgroup analysis, modified transarterial chemoembolization increased survival of patients with a diffuse tumor type (8.9 mo, 95% CI, 5.9-11.9, vs 3.8 mo, 95% CI, 2.5-5.0; P = .000) and patients without metastasis (20.9 mo, 95% CI, 12.2-29.5, vs 7.3 mo, 95% CI, 4.1-10.5; P = .005). Multivariate analysis identified three independent predictive factors for mortality: diffuse tumor type (P = .001), metastasis (P = .009), and modified transarterial chemoembolization protocol (P = .003).

CONCLUSIONS

A survival benefit was suggested with transarterial chemoembolization with additional cisplatin infusion over conventional transarterial chemoembolization in patients with HCC invading the hepatic vein.

DC Bead Transarterial Chemoembolization Is Effective in Hepatocellular Carcinoma Refractory to Conventional Transarteral Chemoembolization: A Pilot Study

Background/Aims

To determine if hepatocellular carcinoma refractory to conventional transarterial chemoembolization (TACE) responds to TACE with DC beads.

Methods

Between July 2008 to June 2010, 435 patients underwent TACE. Of these, 10 patients who had tumors refractory to conventional TACE and who thus were treated with TACE with DC beads were enrolled in this study. The treatment response after TACE with DC beads was evaluated according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) and the Response Evaluation Criteria in Cancer of the Liver (RECICL).

Results

Ten tumors were treated in 10 patients. Using the mRECIST and the RECICL, a complete response was observed in four (40%) of the tumors, and six tumors (60%) showed a partial response. Eight (80%) out of 10 HCCs showed delayed enhancement patterns upon angiography, and better responses were observed in these cases following DC bead treatment. The adverse effects of treatment with DC beads became tolerable.

Conclusions

TACE with DC beads was effective for HCCs refractory to conventional TACE, and this treatment elicited a better response, especially when the tumors were small and showed a delayed enhancement pattern upon angiography.

Transarterial therapies for hepatocellular carcinoma

Transarterial therapies for hepatocellular carcinoma are considered palliative and should be offered to patients with intermediate stage multinodular disease without extra-hepatic metastases and sufficient liver reserve. They mainly include transarterial chemoembolisation and transarterial embolisation. While transarterial therapy is now a validated treatment for unresectable HCC, there is still a lack of conclusive evidence as to which type and schedule is the optimal procedure. This is mainly due to the lack of standardisation. Combining local therapies or intra-arterial therapies with systemic targeted therapies might prove more effective strategies in the future. In the present article, we review transarterial therapies and critically comment on their indications, complications and outcomes.

Hepatic embolotherapy in interventional oncology: technology, techniques, and applications

Embolotherapy continues to play a growing role in the management of primary and secondary hepatic malignancies. In this review article, we examine the basis of therapy with a focus on neovascularization, which makes treatments via the hepatic artery possible. An overview of the three generations of embolic and therapeutic agents follows. The techniques, technologies, and complications of bland embolization, transarterial chemoembolization, drug-eluting beads, and selective internal radiotherapy are covered to give the reader an overview of this exciting field in interventional radiology.

Locoregional drug delivery using image-guided intra-arterial drug eluting bead therapy

Lipiodol-based transarterial chemoembolization (TACE) has been performed for over 3 decades for the treatment of solid tumors and describes the infusion of chemotherapeutic agents followed by embolization with particles. TACE is an effective treatment for inoperable hepatic tumors, especially hypervascular tumors such as hepatocellular carcinoma. Recently, drug eluting beads (DEBs), in which a uniform embolic material is loaded with a drug and delivered in a single image-guided step, have been developed to reduce the variability in a TACE procedure. DEB-TACE results in localization of drug to targeted tumors while minimizing systemic exposure to chemotherapeutics. Once localized in the tissue, drug is eluted from the DEB in a controlled manner and penetrates hundreds of microns of tissue from the DEB surface. Necrosis is evident surrounding a DEB in tissue days to months after therapy; however, the contribution of drug and ischemia is currently unknown. Future advances in DEB technology may include image-ability, DEB size tailored to tumor anatomy and drug combinations.

Cisplatin pharmacokinetics in nontumoral pig liver treated with intravenous or transarterial hepatic chemoembolization

PURPOSE

To evaluate cisplatin (CDDP) pharmacokinetics after its intravenous (IV) or intrahepatic arterial administration (IHA) in healthy pigs with or without embolization by absorbable gelatine.

MATERIAL AND METHODS

We analysed plasmatic and hepatic drug concentration in four groups of six mini-pigs each according to the modality of administration of CDDP (1 mg/kg): IV, IHA, IHA with partial embolization using absorbable gelatine (IHA-Pe), and IHA with complete embolization (IHA-Te). Unbounded plasmatic and hepatic platinum concentrations were measured. Concentration and pharmacokinetics parameters were compared using analysis of variance.

RESULTS

For all groups, there was a rapid and biexponential decrease in free platinum concentration. Plasmatic terminal half-life (T(1/2)) was significantly decreased after embolization at 191, 178, 42, and 41 min after IV, IHA, IHA-Pe, and IHA-Te administration, respectively. Maximal plasmatic concentration and systemic exposure to CDDP (AUC(24)) values were significantly decreased after embolization (C(max) p = 0.0075; AUC(24) p = 0.0053). Hepatic CDDP concentration rapidly peaked and then decreased progressively. After 24 h, the residual concentration represented 45, 47, 60, and 63 % of C(max), respectively, after IV, IHA, IHA-Pe, and IHA-Te. Hepatic T(1/2) and AUC(∞) values were increased after embolization, but the differences were not statistically significant.

CONCLUSION

This preliminary study confirms the feasibility of a pig model to study systemic and hepatic CDDP pharmacokinetics. Systemic exposure is lower after embolization, which could minimize systemic toxicity. Hepatic T(1/2) elimination and hepatic exposition values are increased with IHA compared with IV administration.

Liver/biliary injuries following chemoembolisation of endocrine tumours and hepatocellular carcinoma: lipiodol vs. drug-eluting beads

BACKGROUND & AIMS

Transarterial chemoembolisation (TACE) is usually performed by injecting an emulsion of a drug and iodised oil. Drug-eluting beads (DEBs) have undeniable pharmacological advantages by offering simultaneous embolisation and sustained release of the drug to the tumour. No data are currently available on liver/biliary injury following DEB-TACE. This study describes and compares liver/biliary injuries encountered with TACE in tumours developed in cirrhotic (hepatocellular carcinoma (HCC)) and non-cirrhotic (endocrine tumours (NETs)) livers.

METHODS

In consecutive patients treated for a well-differentiated metastatic NET (n=120) or a HCC (n=88), 684 CT- and MR-scans were analysed. Liver/biliary injuries were classified as follows: dilated bile duct, portal vein narrowing, portal venous thrombosis and biloma/liver infarct. A generalised estimating equation logistic regression model was used.

RESULTS

A liver/biliary injury followed 17.2% (82/476) of sessions in 30.8% (64/208) of patients. The occurrence of liver/biliary injury was associated with DEB-TACE (OR=6.63; p<0.001) irrespectively of the tumour type. Biloma/parenchymal infarct was strongly associated with both DEB-TACE (OR=9.78; p=0.002) and NETs (OR: 8.13; p=0.04). Biloma/liver infarcts were managed conservatively but were associated with an increase in serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatases, and gamma glutamyl transpeptidase (p=0.005, p=0.005, p=0.012, and p=0.006, respectively).

CONCLUSIONS

Liver/biliary injuries are independently associated with DEB-TACE. Biloma/liver infarct, the most serious injury, is independently associated with both DEB-TACE and NETs. The absence of such an association in TACE of HCC may be explained by the hypertrophied peribiliary plexus observed in cirrhosis, which protects against the ischemic/chemical insult of bile ducts. We suggest caution when using DEB-TACE in the non-cirrhotic liver.

Optimization of doxorubicin loading for superabsorbent polymer microspheres: in vitro analysis

PURPOSE

This study was designed to establish the ability of super-absorbent polymer microspheres (SAP) to actively uptake doxorubicin and to establish the proof of principle of SAP's ability to phase transfer doxorubicin onto the polymer matrix and to elute into buffer with a loading method that optimizes physical handling and elution characteristics.

METHODS

Phase I: 50-100 μm SAP subject to various prehydration methods (normal saline 10 cc, hypertonic saline 4 cc, iodinated contrast 10 cc) or left in their dry state, and combined with 50 mg of clinical grade lyophilized doxorubicin reconstituted with various methods (normal saline 10 cc and 25 cc, sterile water 4 cc, iodinated contrast 5 cc) were placed in buffer and assessed based on loading, handling, and elution utilizing high-performance liquid chromatography (HPLC). Phase II: top two performing methods were subject to loading of doxorubicin (50, 75, 100 mg) in a single bolus (group A) or as a serial loading method (group B) followed by measurement of loading vs. time and elution vs. time.

RESULTS

Phase I revealed the most effective loading mechanisms and easiest handling to be dry (group A) vs. normal saline prehydrated (group B) SAP with normal saline reconstituted doxorubicin (10 mg/mL) with loading efficiencies of 83.1% and 88.4%. Phase II results revealed unstable behavior of SAP with 100 mg of doxorubicin and similar loading/elution profiles of dry and prehydrated SAP, with superior handling characteristics of group B SAP at 50 and 75 mg.

CONCLUSIONS

SAP demonstrates the ability to load and bulk phase transfer doxorubicin at 50 and 75 mg with ease of handling and optimal efficiency through dry loading of SAP.

Advances in regional chemotherapy of the liver

INTRODUCTION

Primary and secondary liver tumors resemble some of the most common causes of cancer and represent a major clinical problem owing to the poor prognosis. First-line therapeutic concepts are mainly based on surgical resection and/or systemic chemotherapy (SCT). However, many patients are not suitable for surgery or have failed SCT, although the total tumor load is still limited, which makes a regional therapy approach appealing.

AREAS COVERED

This review focuses on different types of transarterial instillation of chemotherapy, which encompasses conventional and drug-eluting transarterial chemoembolization (TACE), hepatic arterial infusion (HAI) chemotherapy and isolated hepatic perfusion (ILP).

EXPERT OPINION

TACE can be regarded as the treatment of choice in patients with multinodular hepatocellular carcinoma, but it should still be performed as a lipiodol-based regimen, while the value of doxorubicin-eluting beads needs to be exploited in further randomized controlled trials (RCTs). For patients with colorectal liver metastases, HAI chemotherapy has been challenged by the advent of more effective SCT, but encouraging results have been observed for the combination of the most recent, active drugs given by means of HAI with SCT. Nevertheless, data from RCTs comparing SCT with this transarterial regional therapy approach, as well as with TACE and ILP, are urgently needed.

MDCT versus MRI assessment of tumor response after transarterial chemoembolization for the treatment of hepatocellular carcinoma

The purpose of this study was to compare the ability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) to evaluate treatment results after transarterial chemoembolization (TACE), with a special focus on the influence of Lipiodol on calculation of tumor necrosis according to EASL criteria. A total of 115 nodules in 20 patients (17 males, 3 females; 69.5 +/- 9.35 years) with biopsy-proven hepatocellular carcinoma were treated with TACE. Embolization was performed using a doxorubicin-Lipiodol emulsion (group I) or DC Beads loaded with doxorubicin (group II). Follow-up included triphasic contrast-enhanced 64-row MDCT (collimation, 0.625 mm; slice, 3 mm; contrast bolus, 120 ml iomeprol; delay by bolus trigger) and contrast-enhanced MRI (T1 native, T2 native; five dynamic contrast-enhanced phases; 0.1 mmol/kg body weight gadolinium-DTPA; slice thickness, 4 mm). Residual tumor and the extent of tumor necrosis were evaluated according to EASL. Contrast enhancement within tumor lesions was suspected to represent vital tumor. In the Lipiodol-based TACE protocol, MDCT underestimated residual viable tumor compared to MRI, due to Lipiodol artifacts (23.2% vs 47.7% after first, 11.9% vs 31.2% after second, and 11.4% vs 23.7% after third TACE; p = 0.0014, p < 0.001, and p < 0.001, respectively). In contrast to MDCT, MRI was completely free of any artifacts caused by Lipiodol. In the DC Bead-based Lipiodol-free TACE protocol, MRI and CT showed similar residual tumor and rating of treatment results (46.4% vs 41.2%, 31.9 vs 26.8%, and 26.0% vs 25.6%; n.s.). In conclusion, MRI is superior to MDCT for detection of viable tumor residuals after Lipiodol-based TACE. Since viable tumor tissue is superimposed by Lipiodol artifacts in MDCT, MRI is mandatory for reliable decision-making during follow-up after Lipiodol-based TACE protocols.

DNA double-strand breaks and their repair in blood lymphocytes of patients undergoing angiographic procedures

OBJECTIVES

To adapt gamma-H2AX immunofluorescence microscopy to assessment of induction and repair of DNA double-strand breaks (DSBs) in peripheral blood lymphocytes in patients undergoing angiographic procedures.

MATERIALS AND METHODS

The study was approved by the institutional ethics committee. After written informed patient consents were obtained, venous blood samples were taken from 19 patients (age 23-88 years) undergoing different angiographic procedures before, during, and after (10 minutes-24 hours) the examination. Individual DSB yields were visualized by detecting the phosphorylated variant of the histone H2AX (gamma-H2AX) in lymphocytes using fluorescence microscopy. Values were correlated with dose area product. Single in vitro irradiation with 50 mGy was performed in 14 and additional fractionated irradiation with 10 x 5 mGy over a time period corresponding to the angiography duration in 4 patients. The radiation doses to the blood delivered during angiography were estimated by comparing the number of DSBs after angiography with DSB yields obtained after in vitro irradiation.

RESULTS

In all patients in vivo and in vitro irradiation increased the number of DSBs (0.03-1.50 per cell), even if very small doses were applied (minimum 338 microGy x m). Thereafter in both in vitro and in vivo a rapid loss of gamma-H2AX foci was observed. The number of DSBs showed a linear correlation to dose area product for specific examination regions (eg, R = 0.85, pelvic and leg arteries). Calculated radiation doses to blood delivered during angiography ranged from 2.2 to 99.9 mGy and increased if fractioned in vitro samples were used as calibration instead of single in vitro irradiations at the same total dose.

CONCLUSIONS

gamma-H2AX immunofluorescence microscopy is a reliable and sensitive method for measuring the induction and repair of DNA damage caused by ionizing radiation during angiography. To estimate radiation doses delivered during procedures and to consider patients individual repair capacity, postangiography DSB-yields should be compared with DSB-yields after fractioned in vitro irradiation imitating examination conditions.

DC Bead: a major development in the toolbox for the interventional oncologist

The DC Bead is fast becoming the product of choice for use in the treatment of intermediate-stage hepatocellular carcinoma. It is a drug-eluting embolization system that is delivered intra-arterially and combines the effects of physical occlusion of the blood supply to a tumor with the local controlled delivery of a chemotherapeutic agent. While not suitable for use with all drugs, the components of this device enable rapid loading and sustained elution of therapeutic amounts of a range of clinically relevant anticancer compounds. Extensive preclinical testing has demonstrated the reproducibility and reliability of the device, together with reduced systemic drug exposure and sustained local drug delivery. Moreover, these attributes are translating into the clinic as significant benefits to patients with many types of liver tumors.

The current practice of transarterial chemoembolization for the treatment of hepatocellular carcinoma

Despite remarkable advancement in the surveillance and treatment of hepatocellular carcinoma (HCC) and the availability of novel curative options, a great proportion of HCC patients are still not eligible for curative treatment due to an advanced tumor stage or poor hepatic functional reserve. Therefore, there is a continuing need for effective palliative treatments. Although practiced widely, it has only recently been demonstrated that the use of transarterial chemoembolization (TACE) provides a survival benefit based on randomized controlled studies. Hence, TACE has become standard treatment in selected patients. TACE combines the effect of targeted chemotherapy with the effect of ischemic necrosis induced by arterial embolization. Most of the TACE procedures have been based on iodized oil utilizing the microembolic and drug-carrying characteristic of iodized oil. Recently, there have been efforts to improve the delivery of chemotherapeutic agents to a tumor. In this review, the basic principles, technical issues and complications of TACE are reviewed and recent advancement in TACE technique and clinical applicability are briefed.

TACE versus TAE as therapy for hepatocellular carcinoma

Transarterial chemoembolization (TACE) improves survival in cirrhotic patients with hepatocellular carcinoma (HCC). The optimal schedule, best anticancer agent and best technique are still unclear. TACE may not be better than transarterial embolization (TAE). HCC is very chemoresistant, thus embolization may be more important than chemotherapy. Lipiodol cannot be considered as an embolic agent and there are no data to show that it can release chemotherapeutic agents slowly. It can mask residual vascularity on CT imaging and its use is not recommended. Both TACE and TAE result in hypoxia, which stimulates angiogenesis, promoting tumor growth; thus combination of TACE with antiangiogenic agents may improve current results. To date, there is no evidence that TACE pre-liver transplantation or resection helps to expand current selection criteria for patients with HCC, nor results in less recurrence after surgery. Combination with other techniques, such as radiofrequency ablation and drugs, may enhance the effect of TACE. New trials are being conducted to clarify these issues.