Iodixanol versus iopromide in cancer patients: Evidence from a randomized clinical trial

Prevention of post-contrast kidney injury in patients with cancer

Post-contrast acute kidney injury is defined as a nephropathy with an increase in serum creatinine of >0.3 mg/dL (or >26.5 μmol/L) or >1.5-times the baseline within 48-72 h of intravascular administration of a contrast medium. Patients with cancer have an increased risk of post-contrast acute kidney injury not only related to the frequent use of contrast medium for computed tomography scans but also to other factors, including the type of tumour, age, oncological therapies, use of other nephrotoxic agents and dehydration. Preventive strategies were developed and may be applied to different risk profiles. Patients at risk may be detected by recently published risk scores.

Iodixanol as a New Contrast Agent for Cyanoacrylate Embolization: A Preliminary In Vivo Swine Study

N-butyl cyanoacrylate (NBCA) is a lipophilic, permanent embolic glue that must be opacified for fluoroscopic guidance. Empirically, lipophilic Lipiodol Ultra Fluid® (LUF) has been added to produce a single-phase physically stable mixture. Varying the dilution ratio allows control of glue polymerization kinetics. LUF is far more costly than water-soluble iodinated contrast agents (ICAs). Our purpose was to evaluate whether a water-soluble nonionic iso-osmolar ICA could be used instead. We embolized both renal arteries of six swine using 1:3 NBCA-LUF or NBCA-iodixanol in 1:1, 1:3, and 1:7 ratios. We used both micro-computed tomography to assess the distality of glue penetration and indexed cast ratio and histology to assess distality, arterial obliteration, vessel-wall damage, and renal-parenchyma necrosis. Glue-LUF produced significantly greater indexed cast ratio and renal-artery ROI values and a significantly shorter cast-to-capsule distance. The injected volume was significantly greater with 1:7 iodixanol than with the other mixtures. No significant differences were found for histological evidence of artery obliteration, vessel-wall damage, or renal-parenchyma necrosis. This is the first study dealing with ICA alone as a contrast agent for cyanoacrylate embolization, compared to LUF. More research is needed to determine whether water-soluble nonionic iodinated agents can be used for human NBCA embolization given the good safety profile, availability, and low cost of ICA.

Bismuth chelate as a contrast agent for X-ray computed tomography

Backgrounds

Due to the unexpected side effects of the iodinated contrast agents, novel contrast agents for X-ray computed tomography (CT) imaging are urgently needed. Nanoparticles made by heavy metal elements are often employed, such as gold and bismuth. These nanoparticles have the advantages of long in vivo circulation time and tumor targeted ability. However, due to the long residence time in vivo, these nanoparticles may bring unexpected toxicity and, the preparation methods of these nanoparticles are complicated and time—consuming.

Methods

In this investigation, a small molecular bismuth chelate using diethylenetriaminepentaacetic acid (DPTA) as the chelating agent was proposed to be an ideal CT contrast agent.

Results

The preparation method is easy and cost—effective. Moreover, the bismuth agent show better CT imaging for kidney than iohexol in the aspect of improved CT values. Up to 500 µM, the bismuth agent show negligible toxicity to L02 cells and negligible hemolysis. And, the bismuth agent did not induce detectable morphology changes to the main organs of the mice after intravenously repeated administration at a high dose of 250 mg/kg. The pharmacokinetics of the bismuth agent follows the first—order elimination kinetics and, it has a short half—life time of 0.602 h. The rapid clearance from the body promised its excellent biocompatibility.

Conclusions

This bismuth agent may serve as a potential candidate for developing novel contrast agent for CT imaging in clinical applications.

Incidence of contrast-induced acute kidney injury (CI-AKI) in high-risk oncology patients undergoing contrast-enhanced CT with a reduced dose of the iso-osmolar iodinated contrast medium iodixanol

Objectives

To determine the incidence of post-contrast acute kidney injury (PC-AKI) and presumed contrast-induced acute kidney injury (CI-AKI) following contrast-enhanced CT (CECT) with intravenous application of a reduced dose of the iso-osmolar contrast agent iodixanol in cancer patients with chronic kidney disease.

Methods

198 oncology patients with a baseline estimated glomerular filtration rate (eGFR) <60ml/min/1.73m² undergoing a total of 237 CECTs using a reduced dose of 60ml iodixanol were retrospectively analyzed. Statistical analysis was performed for the entire cohort and subgroups. The effect of additional risk factors on the occurrence of PC-AKI was evaluated.

Results

The overall PC-AKI incidence was 6.3%. Excluding patients with concurrent medical conditions known to directly and independently impact kidney function and patients with AKI preceding the CT-scan resulted in a presumed CI-AKI incidence of 3.8%. No permanent post-contrast worsening of renal function and no AKI treatment were required. Subgroups considering baseline eGFR yielded PC-AKI incidences of 4.6% (eGFR 45-60ml/min/1.73m², n = 130), 7.4% (eGFR 30-45ml/min/1.73m², n = 95) and 16.7% (eGFR <30ml/min/1.73m², n = 12). Additional patient related risk factors did not show any significant effect on the occurrence of PC-AKI.

Conclusions

Low incidences of PC-AKI/CI-AKI suggest that a reduced dose of an iso-osmolar contrast agent is safe in high-risk oncological patients with impaired renal function.

Acute kidney injury from contrast-enhanced CT procedures in patients with cancer: white paper to highlight its clinical relevance and discuss applicable preventive strategies

Patients with cancer are subjected to several imaging examinations which frequently require the administration of contrast medium (CM). However, it has been estimated that acute kidney injury (AKI) due to the injection of iodinated CM accounts for 11% of all cases of AKI, and it is reported in up to 2% of all CT examinations. Remarkably, the risks of developing AKI are increased in the elderly, in patients with chronic kidney disease or diabetes, and with dehydration or administration of nephrotoxic chemotherapeutics. Given the common occurrence of postcontrast acute kidney injury (PC-AKI) in clinical practice, primary care physicians and all specialists involved in managing patients with cancer should be aware of the strategies to reduce the risk of this event. In 2018, a panel of four experts from the specialties of radiology, oncology and nephrology were speakers at the annual meeting of the Italian Society of Medical Radiology (Società Italiana di Radiologia Medica e Interventistica), with the aim of commenting on existing evidence and providing their experience on the incidence and management of PC-AKI in patients with cancer. The discussion represented the basis for this white paper, which is intended to be a practical guide organised by statements describing methods to reduce renal injury risks related to CM-enhanced CT examinations in patients with cancer.

Risk of renal events following intravenous iodinated contrast material administration among inpatients admitted with cancer a retrospective hospital claims analysis

BACKGROUND

There is little published evidence examining the use of contrast material (CM) and the risk of acute renal adverse events (AEs) in individuals with increasingly common risk factors including cancer and chronic kidney disease (CKD). The objective of this study was to use real world hospital data to test the hypothesis that inpatients with cancer having CT procedures with iodinated CM would have higher rates of acute renal AEs in comparison to inpatients without cancer.

METHODS

Inpatient hospital visits in the Premier Hospital Database from January 1, 2010 through September 30, 2015 were eligible for inclusion. The outcome of interest was a composite of acute renal AEs including: acute kidney injury, acute renal failure requiring dialysis, contrast induced-acute kidney injury and renal failure. Multivariable models, adjusted for differences in patient demographics and comorbid conditions, were used to estimate the incremental risk of acute renal AEs by CT (with or without iodinated CM), CKD stage and type of cancer.

RESULTS

Among 29,850,475 inpatient visits across 611 hospitals, 7.4% had record of a CT scan, 5.9% had CKD, and 3.4% had the primary diagnosis of cancer. The baseline risk for an acute renal AE in patients without cancer or CKD and no CT or CM was 0.5%. The absolute risk increases from baseline by 0.2% with a CT and by 0.8% with iodinated CM. Patients with CKD having a CT scan with iodinated CM have an absolute risk of 4.1 to 9.7% depending on the stage of CKD. For patients with cancer, the absolute risk increases, varying from 0.3 to 2.3% depending on the type of cancer.

CONCLUSIONS

Inpatients with cancer are at higher likelihood of developing acute renal AEs following CT with iodinated CM compared to those without a cancer. Understanding the underlying risks of acute renal AEs among complex inpatient admissions is an important consideration in treatment choices for oncology patients.