Superparamagnetic iron oxide-enhanced magnetic resonance imaging for focal hepatic lesions: Systematic review and meta-analysis

Magnetic particle imaging angiography of the femoral artery in a human cadaveric perfusion model

BACKGROUND

Magnetic particle imaging (MPI) allows for radiation-free visualization of tracers without background signal. With the first human-sized interventional MPI scanner being recently developed, the aim of the present study was to test its performance for guiding of endovascular procedures in a realistic perfusion model.

METHODS

Three fresh-frozen cadaveric legs were prepared to establish continuous circulation in the superficial femoral artery via introducer sheaths in the inguinal and infragenicular region. To facilitate vessel visualization, a mixture of a MPI tracer (Resotran® or Perimag®) and X-ray contrast agent was injected under continuous extracorporeal perfusion and imaged simultaneously with MPI angiography and digital subtraction angiography (DSA) as reference.

RESULTS

The MPI scanner integrates seamlessly into the standard operating procedures in the angiography suite and simultaneous imaging with DSA and MPI is feasible. The MPI scanner detects a tracer bolus of 2 ml Perimag® or 1.5 ml Resotran®. Imaging results are consistent and reproducible in three cadaveric leg phantoms.

CONCLUSION

This study demonstrates, that the recently developed human-sized MPI scanner facilitates reliable radiation-free image guidance for peripheral vascular interventions in the superficial femoral artery with a tracer approved for use in humans.

Biodistribution and histological analysis of iron oxide-dextran nanoparticles in wistar rats

Iron oxide nanoparticles (IONP) are showing promise in many biomedical applications. One of these- magnetic hyperthermia- utilizes externally applied alternating magnetic fields and tumor-residing magnetic nanoparticles to generate localized therapeutic temperature elevations. Magnetic hyperthermia is approved in Europe to treat glioblastoma and is undergoing clinical assessment in the United States to treat prostate cancer. In this study, we performed biodistribution and histological analysis of a new IONP (RCL-01) in Wistar rats. These nanoparticles are currently undergoing clinical assessment in locally advanced pancreatic ductal adenocarcinoma to determine the feasibility of magnetic hyperthermia treatment in this disease. The study presented here aimed to determine the fate of these nanoparticles in vivo and whether this results in organ damage. Wistar rats were injected intravenously with relatively high doses of IONP (30 mgFe/kg, 45 mgFe/kg and 60 mgFe/kg) and compared to a vehicle control to determine the accumulation of iron in organs and whether this resulted in histological changes in these tissues. Dose-dependent increases of iron were observed in the liver, spleen and lungs of IONP-treated animals at 7 days postinjection; however, this did not result in significant histological changes in these tissues. Immunofluorescent imaging determined these nanoparticles are internalized by macrophages in tissue, suggesting they are readily phagocytosed by the reticuloendothelial system for eventual recycling. Notably, no changes in iron or dextran staining were found in the kidneys across all treatment groups, providing evidence for potential renal clearance.

IOP Injection, A Novel Superparamagnetic Iron Oxide Particle MRI Contrast Agent for the Detection of Hepatocellular Carcinoma: A Phase II Clinical Trial

BACKGROUND

MRI is crucial in diagnosing hepatocellular carcinoma (HCC). Superparamagnetic iron oxide particles (SPIO) are liver-specific contrast agents which enhance lesions in T2 -weighted images. Iron oxide nano-particle m-PEG-silane (IOP) Injection, a newly developed SPIO, showed promising imaging effects and good safety profile in preclinical studies and in phase I clinical trial.

PURPOSE

To evaluate the safety and clinical validity of IOP Injection as MRI contrast agent in diagnosing HCC.

STUDY TYPE

Prospective.

SUBJECTS

A total of 52 subjects (61.6 ± 11.05 years, 45 males/7 females) with suspected HCC.

FIELD STRENGTH/SEQUENCE

1.5 T, T1 -weighted in/opposed phase, T2 *-weighted gradient echo, T2 -weighted fast spin echo, true fast imaging with steady-state free precession.

ASSESSMENT

Adverse effects and clinical monitoring were recorded throughout the 5-day study. Two independent readers (M.G.H. with 30 years of experience, S.P.K. with 26 years of experience) made the diagnosis. The diagnostic performance of IOP-enhanced MRI was evaluated with sensitivity and positive predictive value by comparing to the pathology reports from subsequent hepatic resection. The number of lesions with various sizes and degrees of differentiation detected by IOP-enhanced MRI was assessed. The relative change in signal intensities over time was indirectly measured from acquired images.

STATISTICAL TESTS

Sensitivity and positive predictive value were used to evaluate the diagnostic performance of IOP-enhanced MRI. Prevalence-adjusted and bias-adjusted 𝜅 coefficient was used to assess the interreader variability.

RESULTS

No serious adverse event related to IOP Injection was found. IOP Injection enhanced the lesion-to-liver contrast ratio in T2 *-weighted images by 50.1% ± 4.8%. IOP-enhanced MRI detected HCC with 100% sensitivity by subject and 96% sensitivity by lesion. IOP Injection visualized subtle vascular invasion as filling defect within vessels in true fast imaging with steady-state free precession (TrueFISP) images.

DATA CONCLUSION

IOP Injection was safe and efficacious as MRI contrast agent in diagnosing HCC in a limited group of subjects.

EVIDENCE LEVEL

2.

TECHNICAL EFFICACY

Stage 2.

Magnetic Relaxation Switching Assay Using IFNα-2b-Conjugated Superparamagnetic Nanoparticles for Anti-Interferon Antibody Detection

Type I interferons, particularly IFNα-2b, play essential roles in eliciting adaptive and innate immune responses, being implicated in the pathogenesis of various diseases, including cancer, and autoimmune and infectious diseases. Therefore, the development of a highly sensitive platform for analysis of either IFNα-2b or anti-IFNα-2b antibodies is of high importance to improve the diagnosis of various pathologies associated with the IFNα-2b disbalance. For evaluation of the anti-IFNα-2b antibody level, we have synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coupled with the recombinant human IFNα-2b protein (SPIONs@IFNα-2b). Employing a magnetic relaxation switching assay (MRSw)-based nanosensor, we detected picomolar concentrations (0.36 pg/mL) of anti-INFα-2b antibodies. The high sensitivity of the real-time antibodies' detection was ensured by the specificity of immune responses and the maintenance of resonance conditions for water spins by choosing a high-frequency filling of short radio-frequency pulses of the generator. The formation of a complex of the SPIONs@IFNα-2b nanoparticles with the anti-INFα-2b antibodies led to a cascade process of the formation of nanoparticle clusters, which was further enhanced by exposure to a strong (7.1 T) homogenous magnetic field. Obtained magnetic conjugates exhibited high negative MR contrast-enhancing properties (as shown by NMR studies) that were also preserved when particles were administered in vivo. Thus, we observed a 1.2-fold decrease of the T2 relaxation time in the liver following administration of magnetic conjugates as compared to the control. In conclusion, the developed MRSw assay based on SPIONs@IFNα-2b nanoparticles represents an alternative immunological probe for the estimation of anti-IFNα-2b antibodies that could be further employed in clinical studies.

CT and MRI Imaging of Theranostic Bimodal Fe3O4@Au NanoParticles in Tumor Bearing Mice

Gold-containing nanoparticles are proven to be an effective radiosensitizer in the radiotherapy of tumors. Reliable imaging of nanoparticles in a tumor and surrounding normal tissues is crucial both for diagnostics and for nanoparticle application as radiosensitizers. The Fe₃O₄ core was introduced into gold nanoparticles to form a core/shell structure suitable for MRI imaging. The aim of this study was to assess the in vivo bimodal CT and MRI enhancement ability of novel core/shell Fe₃O₄@Au theranostic nanoparticles. Core/shell Fe₃O₄@Au nanoparticles were synthesized and coated with PEG and glucose. C57Bl/6 mice bearing Ca755 mammary adenocarcinoma tumors received intravenous injections of the nanoparticles. CT and MRI were performed at several timepoints between 5 and 102 min, and on day 17 post-injection. Core/shell Fe₃O₄@Au nanoparticles provided significant enhancement of the tumor and tumor blood vessels. Nanoparticles also accumulated in the liver and spleen and were retained in these organs for 17 days. Mice did not show any signs of toxicity over the study duration. These results indicate that theranostic bimodal Fe₃O₄@Au nanoparticles are non-toxic and serve as effective contrast agents both for CT and MRI diagnostics. These nanoparticles have potential for future biomedical applications in cancer diagnostics and beyond.

Diagnostic and therapeutic roles of iron oxide nanoparticles in biomedicine

Nanotechnology changed our understanding of physics and chemics and influenced the biomedical field. Iron oxide nanoparticles (IONs) are one of the first emerging biomedical applications of nanotechnology. The IONs are composed of iron oxide core exhibiting magnetism and coated with biocompatible molecules. The small size, strong magnetism, and biocompatibility of IONs facilitate the application of IONs in the medical imaging field. We listed several clinical available IONs including Resovist (Bayer Schering Pharma, Berlin, Germany) and Feridex intravenous (I.V.)/Endorem as magnetic resonance (MR) contrast agents for liver tumor detection. We also illustrated GastroMARK as a gastrointestinal contrast agent for MR imaging. Recently, IONs named Feraheme for treating iron-deficiency anemia have been approved by the Food and Drug Administration. Moreover, tumor ablation by IONs named NanoTherm has also been discussed. In addition to the clinical application, several potential biomedical applications of IONs including cancer-targeting capability by conjugating IONs with cancer-specific ligands, cell trafficking tools, or tumor ablation agents have also been discussed. With the growing awareness of nanotechnology, further application of IONs is still on the horizon that would shed light on biomedicine.

Magnetic resonance imaging for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease and ranks sixth in terms of global incidence of cancer, and third in terms of cancer deaths. In clinical practice, magnetic resonance imaging (MRI) is used as a second-line diagnostic imaging modality to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma on prior diagnostic test such as abdominal ultrasound or alpha-fetoprotein, or both, either in surveillance programmes or in clinical settings. According to current guidelines, a single contrast-enhanced imaging study (computed tomography (CT) or MRI) showing typical hallmarks of hepatocellular carcinoma in people with cirrhosis is considered valid to diagnose hepatocellular carcinoma. The detection of hepatocellular carcinoma amenable to surgical resection could improve the prognosis. However, a significant number of hepatocellular carcinomas do not show typical hallmarks on imaging modalities, and hepatocellular carcinoma may, therefore, be missed. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival: the conflicting results can be a consequence of inaccurate detection, ineffective treatment, or both. Assessing the diagnostic accuracy of MRI may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of MRI in people with chronic liver disease who are not included in surveillance programmes is needed for either ruling out or diagnosing hepatocellular carcinoma.

OBJECTIVES

Primary: to assess the diagnostic accuracy of MRI for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease. Secondary: to assess the diagnostic accuracy of MRI for the diagnosis of resectable hepatocellular carcinoma in adults with chronic liver disease, and to identify potential sources of heterogeneity in the results.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Hepato-Biliary Group Diagnostic Test of Accuracy Studies Register, the Cochrane Library, MEDLINE, Embase, and three other databases to 9 November 2021. We manually searched articles retrieved, contacted experts, handsearched abstract books from meetings held during the last 10 years, and searched for literature in OpenGrey (9 November 2021). Further information was requested by e-mails, but no additional information was provided. No data was obtained through correspondence with investigators. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of MRI for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened studies, extracted data, and assessed the risk of bias and applicability concerns, using the QUADAS-2 checklist. We presented the results of sensitivity and specificity, using paired forest plots, and we tabulated the results. We used a hierarchical meta-analysis model where appropriate. We presented uncertainty of the accuracy estimates using 95% confidence intervals (CIs). We double-checked all data extractions and analyses.

MAIN RESULTS

We included 34 studies, with 4841 participants. We judged all studies to be at high risk of bias in at least one domain because most studies used different reference standards, often inappropriate to exclude the presence of the target condition, and the time interval between the index test and the reference standard was rarely defined. Regarding applicability, we judged 15% (5/34) of studies to be at low concern and 85% (29/34) of studies to be at high concern mostly owing to characteristics of the participants, most of whom were on waiting lists for orthotopic liver transplantation, and due to pathology of the explanted liver being the only reference standard. MRI for hepatocellular carcinoma of any size and stage: sensitivity 84.4% (95% CI 80.1% to 87.9%) and specificity 93.8% (95% CI 90.1% to 96.1%) (34 studies, 4841 participants; low-certainty evidence). MRI for resectable hepatocellular carcinoma: sensitivity 84.3% (95% CI 77.6% to 89.3%) and specificity 92.9% (95% CI 88.3% to 95.9%) (16 studies, 2150 participants; low-certainty evidence). The observed heterogeneity in the results remains mostly unexplained. The sensitivity analyses, which included only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted without knowledge of the results of the index test, showed no variation in the results.

AUTHORS' CONCLUSIONS

We found that using MRI as a second-line imaging modality to diagnose hepatocellular carcinoma of any size and stage, 16% of people with hepatocellular carcinoma would be missed, and 6% of people without hepatocellular carcinoma would be unnecessarily treated. For resectable hepatocellular carcinoma, we found that 16% of people with resectable hepatocellular carcinoma would improperly not be resected, while 7% of people without hepatocellular carcinoma would undergo inappropriate surgery. The uncertainty resulting from the high risk of bias in the included studies and concerns regarding their applicability limit our ability to confidently draw conclusions based on our results.

Recent advances in hepatocellular carcinoma therapeutic strategies and imaging-guided treatment

Hepatocellular carcinoma (HCC) is one of the most common malignant cancer in the world, which greatly threatens human health. However, the routine treatment strategies for HCC have failed to specifically eradicate the tumorigenic cells, leading to the occurrence of metastasis and recurrence. To improve treatment efficacies, the development of novel effective technologies is urgently required. Recently, nanotechnologies have gained the extensive attention in cancer targeted therapy, which could provide a promising way for HCC clinical practice. However, a successful cancer management depends on accurate diagnosis of the tumour along with precise therapeutic protocol, thereby predicting the tumour response to existing therapies. The synergistic effect of targeted therapeutic systems and imaging approaches (also called 'imaging-guided cancer treatment') may establish a more effective platform for individual cancer care. This review outlines the recent advanced nano-targeted and -traceable therapeutic strategies for HCC management. The multifunctional nano agents that have both diagnosis and therapy abilities are highlighted. Finally, we conclude with our perspectives on the future development and challenges of HCC nanotheranostics.

Advances in the early diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers globally. In contrast to the declining death rates observed for all other common cancers such as breast, lung, and prostate cancers, the death rates for HCC continue to increase by ~2–3% per year because HCC is frequently diagnosed late and there is no curative therapy for an advanced HCC. The early diagnosis of HCC is truly a big challenge. Over the past years, the early diagnosis of HCC has relied on surveillance with ultrasonography (US) and serological assessments of alpha-fetoprotein (AFP). However, the specificity and sensitivity of US/AFP is not satisfactory enough to detect early onset HCC. Recent technological advancements offer hope for early HCC diagnosis. Herein, we review the progress made in HCC diagnostics, with a focus on emerging imaging techniques and biomarkers for early disease diagnosis.

Diagnostic accuracy of midkine for hepatocellular carcinoma: A meta-analysis

Background

There have been many reports on midkine as a promising marker in the diagnosis of hepatocellular carcinoma (HCC). However, the results are inconsistent and even conflicting.

Methods

This meta‐analysis was performed to investigate the accuracy of midkine in the diagnosis of HCC. Meta‐DiSc 1.4 software was used to extract data and to calculate the overall sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Data are presented as forest plots and summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance.

Results

Ten studies with a total of 753 HCC patients and 977 non‐HCC patients were included. The overall pooled diagnostic data were as follows: the pooled sensitivity of 0.86 (95% confidence interval [CI]: 083–0.88), the pooled specificity of 0.75 (95% CI: 0.73–0.78), the pooled PLR of 4.71 (95% CI: 2.80–7.90), the pooled NLR of 0.18 (95% CI: 0.11–0.30), and the pooled DOR of 36.83 (95% CI: 13.56–100.05). The area under curve value was 0.9266 in the overall SROC curve.

Conclusion

Midkine has moderate diagnostic accuracy for HCC. Due to the design limitations, results inpublished studies should be carefully interpreted. In addition, more well‐designed studies with large sample sizes should be performed to rigorously evaluate the diagnostic accuracy of the MDK.

How to Provide Gadolinium-Free PET/MR Cancer Staging of Children and Young Adults in Less than 1 h: the Stanford Approach

PURPOSE

To provide clinically useful gadolinium-free whole-body cancer staging of children and young adults with integrated positron emission tomography/magnetic resonance (PET/MR) imaging in less than 1 h.

PROCEDURES

In this prospective clinical trial, 20 children and young adults (11-30 years old, 6 male, 14 female) with solid tumors underwent 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) PET/MR on a 3T PET/MR scanner after intravenous injection of ferumoxytol (5 mg Fe/kg) and [¹⁸F]FDG (2-3 MBq/kg). Time needed for patient preparation, PET/MR image acquisition, and data processing was compared before (n = 5) and after (n = 15) time-saving interventions, using a Wilcoxon test. The ferumoxytol-enhanced PET/MR images were compared with clinical standard staging tests regarding radiation exposure and tumor staging results, using Fisher's exact tests.

RESULTS

Tailored workflows significantly reduced scan times from 36 to 24 min for head to mid thigh scans (p < 0.001). These streamlined PET/MR scans were obtained with significantly reduced radiation exposure (mean 3.4 mSv) compared to PET/CT with diagnostic CT (mean 13.1 mSv; p = 0.003). Using the iron supplement ferumoxytol "off label" as an MR contrast agent avoided gadolinium chelate administration. The ferumoxytol-enhanced PET/MR scans provided equal or superior tumor staging results compared to clinical standard tests in 17 out of 20 patients. Compared to PET/CT, PET/MR had comparable detection rates for pulmonary nodules with diameters of equal or greater than 5 mm (94 vs. 100 %), yet detected significantly fewer nodules with diameters of less than 5 mm (20 vs 100 %) (p = 0.03). [¹⁸F]FDG-avid nodules were detected with slightly higher sensitivity on the PET of the PET/MR compared to the PET of the PET/CT (59 vs 49 %).

CONCLUSION

Our streamlined ferumoxytol-enhanced PET/MR protocol provided cancer staging of children and young adults in less than 1 h with equivalent or superior clinical information compared to clinical standard staging tests. The detection of small pulmonary nodules with PET/MR needs to be improved.

In vitro toxicity of FemOn, FemOn-SiO2 composite, and SiO2-FemOn core-shell magnetic nanoparticles

Over the last decade, magnetic iron oxide nanoparticles (IONPs) have drawn much attention for their potential biomedical applications. However, serious in vitro and in vivo safety concerns continue to exist. In this study, the effects of uncoated, FemOn-SiO2 composite flake-like, and SiO2-FemOn core-shell IONPs on cell viability, function, and morphology were tested 48 h postincubation in human umbilical vein endothelial cell culture. Cell viability and apoptosis/necrosis rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and annexin V-phycoerythrin kit, respectively. Cell morphology was evaluated using bright-field microscopy and forward and lateral light scattering profiles obtained with flow cytometry analysis. All tested IONP types were used at three different doses, that is, 0.7, 7.0, and 70.0 μg. Dose-dependent changes in cell morphology, viability, and apoptosis rate were shown. At higher doses, all types of IONPs caused formation of binucleated cells suggesting impaired cytokinesis. FemOn-SiO2 composite flake-like and SiO2-FemOn core-shell IONPs were characterized by similar profile of cytotoxicity, whereas bare IONPs were shown to be less toxic. The presence of either silica core or silica nanoflakes in composite IONPs can promote cytotoxic effects.

Clinically Approved Nanoparticle Imaging Agents

Nanoparticles are a new class of imaging agent used for both anatomic and molecular imaging. Nanoparticle-based imaging exploits the signal intensity, stability, and biodistribution behavior of submicron-diameter molecular imaging agents. This review focuses on nanoparticles used in human medical imaging, with an emphasis on radionuclide imaging and MRI. Newer nanoparticle platforms are also discussed in relation to theranostic and multimodal uses.

Current status of superparamagnetic iron oxide contrast agents for liver magnetic resonance imaging

Five types of superparamagnetic iron oxide (SPIO), i.e. Ferumoxides (Feridex^® IV, Berlex Laboratories), Ferucarbotran (Resovist^®, Bayer Healthcare), Ferumoxtran-10 (AMI-227 or Code-7227, Combidex^®, AMAG Pharma; Sinerem^®, Guerbet), NC100150 (Clariscan^®, Nycomed,) and (VSOP C184, Ferropharm) have been designed and clinically tested as magnetic resonance contrast agents. However, until now Resovist^® is current available in only a few countries. The other four agents have been stopped for further development or withdrawn from the market. Another SPIO agent Ferumoxytol (Feraheme^®) is approved for the treatment of iron deficiency in adult chronic kidney disease patients. Ferumoxytol is comprised of iron oxide particles surrounded by a carbohydrate coat, and it is being explored as a potential imaging approach for evaluating lymph nodes and certain liver tumors.

Diagnostic Value of the Combination of Golgi Protein 73 and Alpha-Fetoprotein in Hepatocellular Carcinoma: A Meta-Analysis

Conflicting results have been widely reported on the use of Golgi protein 73 (GP73) as a serum biomarker for diagnosing hepatocellular carcinoma (HCC). This study evaluated the accuracy of GP73, alpha-fetoprotein (AFP), and GP73 + AFP for diagnosing HCC. The meta-analysis was performed on 11 studies that were selected by means of a comprehensive systematic literature review. Summary diagnostic accuracy, meta-regression analysis for heterogeneity and publication bias, and other statistical analyses were performed using Meta-Disc (version 1.4) and Stata (version 12.0). Pooled sensitivity, specificity, and diagnostic odds ratio were 0.77 (95% CI: 0.75–0.79), 0.91 (95% CI: 0.90–0.92), and 12.49 (95% CI: 4.91–31.79) for GP73; 0.62 (95% CI: 0.60–0.64), 0.84 (95% CI: 0.83–0.85), and 11.61 (95% CI: 8.02–16.81) for AFP; and 0.87 (95% CI: 0.85–0.89), 0.85 (95% CI: 0.84–0.86), and 30.63 (95% CI: 18.10–51.84) for GP73 + AFP. The area under the curve values were 0.86, 0.84, and 0.91 for GP73, AFP, and GP73 + AFP, respectively. These results indicate that for HCC diagnosis, the accuracy of GP73 was higher than that of AFP, and that GP73 + AFP exhibited significantly higher diagnostic accuracy than did GP73 or AFP alone.

On-demand drug delivery from local depots

Stimuli-responsive polymeric depots capable of on-demand release of therapeutics promise a substantial improvement in the treatment of many local diseases. These systems have the advantage of controlling local dosing so that payload is released at a time and with a dose chosen by a physician or patient, and the dose can be varied as disease progresses or healing occurs. Macroscale drug depot can be induced to release therapeutics through the action of physical stimuli such as ultrasound, electric and magnetic fields and light as well as through the addition of pharmacological stimuli such as nucleic acids and small molecules. In this review, we highlight recent advances in the development of polymeric systems engineered for releasing therapeutic molecules through physical and pharmacological stimulation.