Assessment of genetic damage induced by gadolinium-based radiocontrast agents

BACKGROUND

Today, although gadolinium based contrast agents have been frequently used in the field of medicine, there is limited data available whether gadolinium based agents affect the genome.

AIM

The present study aimed to investigate the genotoxic and cytotoxic potentials of gadoteric acid and gadoversetamide used as gadolinium-based contrast agents for magnetic resonance (MR) imaging.

MATERIAL AND METHODS

The cytokinesis-block micronucleus assay was applied to human peripheral blood lymphocytes to assess the genotoxicity measured as micronucleus (MN), nucleoplasmic bridge (NPBs) and nuclear bud (NBUDs) frequencies. Furthermore, cytokinesis-block proliferation index (CBPI) was calculated to determine cytostasis. Lymphocytes were treated with gadoteric acid at concentrations of 1.0, 2.5, 5.0, and 25 mM and with gadoversetamide at concentrations of 0.25, 1.0, 2.5, and 5.0 mM for 48 h.

RESULTS

Gadoteric acid did not cause significant increase in MN, NBPs and NBUDs frequencies and CBPI values at any concentration. Gadoversetamide induced significantly increase MN formation at concentration of 2.5 mM, NBP formation at concentrations of 1.0 and 2.5 mM, and NBUD formation at concentrations of 0.25, 1.0 and 2.5 mM. Additionally, gadoversetamide exposure resulted in statistically significant decrease in CBPI values compared to the control at concentrations of 2.5 and 5.0 mM. In addition, CBPI levels in response to concentrations of gadoversetamide was negatively and significantly associated with concentration.

CONCLUSION

These findings show that gadoteric acid does not have genotoxic or cytotoxic potential, while gadoversetamide might have both genotoxic and cytotoxic potential on human peripheral blood lymphocytes. As a comparison, gadoversetamide was found more genotoxic and cytotoxic.

Repeated gadoteric acid and gadobutrol exposure causes deterioration of behavior and memory functions in rats: MRI, histopathological and biochemical evidence

Gadolinium-based contrast agents (GBCAs) exert effects in different regions of the brain; however, studies on this topic are mostly focused on radiological outcomes of GBCA exposure. This paper is a preliminary attempt to identify whether there are changes in behavioral, cognitive, histopathological, radiological and biochemical characteristics with repeated exposure to gadobutrol and gadoteric acid. The effects of GBCAs were tested with the assessment of 4 groups -each comprised of 6 rats [controls, gadobutrol, gadoteric acid (Doteram), and gadoteric acid (Clariscan)]. Respective treatments of 0.1 ml/kg were administered for 3 weeks, followed by a recovery period of 1 week without any treatment. At the end of this regimen, behavioral tests (open field and passive learning test) were performed. Additionally, histopathological analysis of the hippocampal CA1 and CA3 regions (GFAP measurement and total neuron count), biochemical measurements [TNF-a, Malondialdehyde (MDA), Superoxide dismutase (SOD), homovalinic acid (HVA) and choline acetyl transferase (ChAT) levels], and radiological findings (MRI-region of interest) were carried out in each group. There was a significant impairment in all groups that had received gadolinium in open field and passive avoidance learning tests. Oxidative stress and inflammation markers were significantly elevated in all gadolinium groups. Additionally, increased hippocampal gliosis and decreased MRI-ROIs were observed in rats exposed to gadolinium. Chronic gadoteric acid and gadobutrol exposure causes hippocampal gliosis and elevates oxidative stress and inflammation in rats. Radiological outcomes are also consistent with these findings. Long-term studies might be required to conclude whether gadolinium deposition in the brain causes subtle neurological deficits.

Incidence of nephrogenic systemic fibrosis after administration of gadoteric acid in patients on renal replacement treatment

PURPOSE

Nephrogenic system fibrosis (NSF) is a rare complication detected in patients with renal insufficiency exposed to gadolinium-based contrast agents (GBCAs). The aim of our study is to evaluate the prevalence of NSF in a cohort of patients on renal replacement treatment who underwent GBCA-enhanced magnetic resonance imaging (MRI).

METHOD

We retrospectively reviewed all the charts of kidney transplant (KT) recipients, patients on hemodialysis (HD) and peritoneal dialysis (PD) who received a uniform protocol for contrast material enhanced-MRI with gadoteric acid at our center from January 2004 to December 2017.

RESULTS

Three-hundred forty-four patients (44.1% on HD, 11.3% on PD and 44.4% KT recipients) underwent 551 gadoteric acid-enhanced MRI. The median age of the patients was 58 years (IQR, 45-70 years) and 65.1% were men. Sixty-three patients (18.3%) had skin punch biopsy after integumentary assessment performed by a dermatologist. No cases of NSF were detected after a median follow-up of 4.5 years (IQR, 1.9-8.2 years). During this period of observation, 116 (33.7%) patients died and 11 (3.1%) were lost at follow-up.

CONCLUSIONS

None of the patients exposed to gadoteric acid developed NSF. Our results, in line with more recent studies, suggest that the use of gadoteric acid, a macrocyclic GBCA, appears safe even in chronic kidney disease (CKD) patients receiving dialysis.

T1-Weighted Intensity Increase After a Single Administration of a Linear Gadolinium-Based Contrast Agent in Multiple Sclerosis

Purpose

Through analysis of T1-weighted (T1w) images this study investigated gadolinium (Gd) deposition in the brain after administration of a linear (gadopentetic acid) and a cyclic (gadoteric acid) gadolinium-based contrast agent (GBCA) in patients with multiple sclerosis (MS), a disorder frequently requiring magnetic resonance imaging (MRI) scans over years.

Methods

A total of 3233 T1w images (unenhanced with respect to the same scanning session) of 881 MS patients were retrospectively analyzed. After spatial normalization and intensity scaling using a sphere within the pons, differences of all pairs of subsequent scans were calculated and attributed to either linear (n = 2718) or cyclic (n = 385) or no GBCA (n = 130) according to the first scan. Regional analyses were performed, focusing on the dentate nucleus, and whole brain analyses. By 1‑sample t‑tests, signal intensity increases within conditions were searched for; conditions were compared by 2‑sample t‑tests. Furthermore, recent hypotheses on the reversibility of GBCA deposition were tested.

Results

In the dentate nucleus, a significant increase was observed only after administration of linear GBCA even after a single GBCA administration. This increase differed significantly (p < 0.001) from the other conditions (cyclic and no GBCA). Whole brain analyses revealed T1w signal increases only after administration of linear GBCA within two regions, the dentate nucleus and globus pallidus. Additional analyses did not indicate any decline of Gd deposition in the brain.

Conclusion

The data point towards Gd deposition in the brain after administration of linear GBCA even after a single administration.

Impact of gadolinium-based contrast agents on the growth of fish cells lines

The present study was the first approach conducted under environmental concentrations of Gd-DOTA and Gd-DTPA-BMA to assess cellular impacts of these compounds. Gd-DOTA (Gadoteric acid) is one of the most stable contrast agent, currently used as Dotarem^® formulation during Magnetic Resonance Imaging exams. The study was mainly performed on a Zebra Fish cell line (ZF4; ATCC CRL-2050). At the concentrations of 0.127 nM and 63.59 nM (respectively 20 ng and 10 μg of Gd/L), we did not observed any toxicity of Dotarem^® but a slowdown of the cell growth was clearly measured. The effect is independent of medium renewing during 6 days of cell culturing. The same effect was observed i-with Gd-DOTA on another fish cell line (RT W1 gills; ATCC CRL-2523) and ii-with another contrast agent (Gd-DTPA-BMA - Omniscan^®) on ZF4 cells. On the ZF4 cell line, the diminution of the cell growth was of the same order during 20 days of exposure to a culture medium spiked with 63.59 nM of Dotarem^® and was reversible within the following 8 days when Dotarem^® was removed from the medium. As shown by using modified DOTA structure (Zn-DOTA), the effect may be due to the chelating structure of the contrast agent rather than to the Gd ion. Until now, the main attention concerning the impact of Gd-CA on living cells concerned the hazard due to Gd release. According to our results, quantifying the presence of Gd-CA chelating structures in aquatic environments must be also monitored.

Intraventricular Gadoteric Acid Intoxication: First Report

BACKGROUND

Gadolinium-based contrast agents are relatively safe for use in magnetic resonance imaging (MRI) of nervous system pathology. Few reports have been reported regarding the severe adverse effects. These are mostly mild anaphylactoid reactions, especially in the vulnerable group.

CASE DESCRIPTION

We report a case of an adverse effect of gadoteric acid concerning the misuse as intraventricular administration. To our knowledge, this is the first report related to intraventricular spillage and its results. A 38-year-old male patient with a complaint of headache and drowsiness was admitted to the hospital, after which cranial MRI revealed that he had a posterior fossa mass. An operation was performed with the catheterization of the lateral ventricule as a safety device at the beginning, and later mass was evacuated gross totally. Frozen pathology result showed the tumor was medulloblastoma. On the first postoperative day a control contrasted cranial and total spinal MRI was planned. He was observed to have a tonic-clonic generalized seizure soon after returning to the ward. After giving the acute management with antiepileptics, the patient was stabilized and it was recognized that the patient was administered contrast media by the intraventricular route. Symptomatic treatment and cerebrospinal fluid irrigation by external ventricular drainage helped the patient's improvement. After a week his symptoms were relieved and he had no complications during outpatient controls.

CONCLUSIONS

In addition to formal basic supportive treatment, cerebrospinal fluid irrigation of the toxic contrast material is the best management method in case of such an unexpected misadministration of gadoteric acid.

[Inferior myocardial infarction complicated by complete heart block and cardiac arrest following a gadolinium injection: A case of Kounis syndrome]

Kounis syndrome is an allergic acute coronary syndrome. It occurs on healthy or pathological arteries. Its complications, although often benign, can lead to cardiac arrest and death. Its triggering factors are multiple and include contrast products used in diagnostic imaging. We report the case of an 81 years old patient affected by hepatocellular carcinoma, who presented a type 2 Kounis syndrome with inferior myocardial infarction, complicated by cardiac arrest related to complete heart block following a gadoteric acid injection.

Physical rupture of the xylem in developing sweet cherry fruit causes progressive decline in xylem sap inflow rate

Xylem flow is progressively shut down during maturation beginning with minor veins at the stylar end and progressing to major veins and finally to bundles at the stem end. This study investigates the functionality of the xylem vascular system in developing sweet cherry fruit (Prunus avium L.). The tracers acid fuchsin and gadoteric acid were fed to the pedicel of detached fruit. The tracer distribution was studied using light microscopy and magnetic resonance imaging. The vasculature of the sweet cherry comprises five major bundles. Three of these supply the flesh; two enter the pit to supply the ovules. All vascular bundles branch into major and minor veins that interconnect via numerous anastomoses. The flow in the xylem as indexed by the tracer distribution decreases continuously during development. The decrease is first evident at the stylar (distal) end of the fruit during pit hardening and progresses basipetally towards the pedicel (proximal) end of the fruit at maturity. That growth strains are the cause of the decreased conductance is indicated by: elastic strain relaxation after tissue excision, the presence of ruptured vessels in vivo, the presence of intrafascicular cavities, and the absence of tyloses.

Diagnostic efficacy and safety of gadoteric acid MR mammography in 1537 patients

OBJECTIVES

To perform a large-scale multicenter post-marketing surveillance study for analyzing diagnostic effectiveness and safety of intravenous (IV) gadoteric acid (Dotarem^®) in magnetic resonance (MR) mammography under daily practice conditions.

MATERIALS AND METHODS

Patients underwent high-resolution MR mammography with gadoteric acid in 15 German centers. Radiologists used a standardized questionnaire to report data including patient demographics and medical history, characteristics of MR examination and results in terms of diagnosis and safety for the patient.

RESULTS

A total of 1537 patients were examined. In 99.2% of all patients, a diagnosis was established. In 91.6% of all patients, image quality was excellent or good. Histopathological examinations were performed for 232 of 1537 patients (15.1%) with invasive ductal carcinoma being the most frequent diagnosis (109 patients, 47.0%). Based on histopathology as the standard of reference, IV gadoteric acid-enhanced MR mammography confirmed diagnoses of invasive ductal carcinoma in 93.5% of the patients. Adverse drug reactions occurred in 5 of 1537 patients (0.3%) and were classified as serious in one case (tachycardia, dysphagia, urticaria, rash). All patients with adverse drug reactions fully recovered after the examination.

CONCLUSION

This noninterventional surveillance study shows IV gadoteric acid to be a safe and effective contrast agent for use in MR mammography.

Safety and efficacy of gadoteric acid in pediatric magnetic resonance imaging: overview of clinical trials and post-marketing studies

BACKGROUND

Gadoteric acid is a paramagnetic gadolinium macrocyclic contrast agent approved for use in MRI of cerebral and spinal lesions and for body imaging.

OBJECTIVE

To investigate the safety and efficacy of gadoteric acid in children by extensively reviewing clinical and post-marketing observational studies.

MATERIALS AND METHODS

Data were collected from 3,810 children (ages 3 days to 17 years) investigated in seven clinical trials of central nervous system (CNS) imaging (n = 141) and six post-marketing observational studies of CNS, musculoskeletal and whole-body MR imaging (n = 3,669). Of these, 3,569 children were 2-17 years of age and 241 were younger than 2 years. Gadoteric acid was generally administered at a dose of 0.1 mmol/kg. We evaluated image quality, lesion detection and border delineation, and the safety of gadoteric acid. We also reviewed post-marketing pharmacovigilance experience.

RESULTS

Consistent with findings in adults, gadoteric acid was effective in children for improving image quality compared with T1-W unenhanced sequences, providing diagnostic improvement, and often influencing the therapeutic approach, resulting in treatment modifications. In studies assessing neurological tumors, gadoteric acid improved border delineation, internal morphology and contrast enhancement compared to unenhanced MR imaging. Gadoteric acid has a well-established safety profile. Among all studies, a total of 10 children experienced 20 adverse events, 7 of which were thought to be related to gadoteric acid. No serious adverse events were reported in any study. Post-marketing pharmacovigilance experience did not find any specific safety concern.

CONCLUSION

Gadoteric acid was associated with improved lesion detection and delineation and is an effective and well-tolerated contrast agent for use in children.