Double-dose 1.0-M gadobutrol versus standard-dose 0.5-M gadopentetate dimeglumine in revealing small hypervascular hepatocellular carcinomas

Clinical Efficacy of Gadobutrol: Review of Over 25 Years of Use Exceeding 100 Million Administrations

BACKGROUND

Gadobutrol has been administered more than 100 million times worldwide, since February 1998, that is, over the last 25 years. Numerous clinical studies in a broad range of indications document the long-term experience with gadobutrol.

OBJECTIVE

The aim of this study was to provide a literature-based overview on gadobutrol's efficacy in 9 approved indications and use in children.

MATERIALS AND METHODS

Efficacy results in patients of all age groups including sensitivity, specificity, accuracy, and positive/negative predictive values were identified by a systematic literature search on Embase until December 31, 2022. Nine approved indications were considered: central nervous system (CNS), magnetic resonance angiography (MRA), breast, heart, prostate, kidney, liver, musculoskeletal, whole body, and various indications in children.

RESULTS

Sixty-five publications (10 phase III, 2 phase IV, 53 investigator-initiated studies) reported diagnostic efficacy results obtained from 7806 patients including 271 children, at 369 centers worldwide. Indication-specific sensitivity ranges were 59%-98% (CNS), 53%-100% (MRA), 80%-100% (breast), 64%-90% (heart), 64%-96% (prostate), 71-85 (kidney), 79%-100% (liver), 53%-98% (musculoskeletal), and 78%-100% (children). Indication-specific specificity ranges were 75%-100% (CNS), 64%-99% (MRA), 58%-98% (breast), and 47%-100% (heart).

CONCLUSIONS

The evaluated body of evidence, consisting of 65 studies with 7806 patients, including 271 children and 7535 adults, showed that gadobutrol is an efficacious magnetic resonance imaging contrast agent for all age groups in various approved indications throughout the whole body.

Assessment of the hepatic tumor extracellular matrix using elastin-specific molecular magnetic resonance imaging in an experimental rabbit cancer model

To investigate the imaging performance of an elastin-specific molecular magnetic resonance imaging (MRI) probe with respect to the extracellular matrix (ECM) in an experimental hepatic cancer model. Twelve rabbits with hepatic VX2 tumors were examined using 3 T MRI 14, 21, and 28 days after tumor implantation for two subsequent days (gadobutrol, day 1; elastin-specific probe, day 2). The relative enhancement (RE) of segmented tumor regions (central and margin) and the peritumoral matrix was calculated using pre-contrast and delayed-phase T1w sequences. MRI measurements were correlated to histopathology and element-specific and spatially resolved mass spectrometry (MS). Mixed-model analysis was performed to assess the performance of the elastin-specific probe. In comparison to gadobutrol, the elastin probe showed significantly stronger RE, which was pronounced in the tumor margin (day 14–28: P ≤ 0.007). In addition, the elastin probe was superior in discriminating between tumor regions (χ²(4) = 65.87; P < 0.001). MRI-based measurements of the elastin probe significantly correlated with the ex vivo elastinstain (R = .84; P <0 .001) and absolute gadolinium concentrations (ICP-MS: R = .73, P <0 .01). LA-ICP-MS imaging confirmed the colocalization of the elastin-specific probe with elastic fibers. Elastin-specific molecular MRI is superior to non-specific gadolinium-based contrast agents in imaging the ECM of hepatic tumors and the peritumoral tissue.

Dynamic contrast-enhanced MR imaging of the prostate: intraindividual comparison of gadoterate meglumine and gadobutrol

OBJECTIVES

To intraindividually compare the signal-enhancing effect of 0.5 M gadoterate meglumine and 1.0 M gadobutrol in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging of the prostate.

METHODS

Fifty patients who underwent two 3-T MR examinations of the prostate were included in this IRB-approved retrospective uncontrolled, unrandomized study. All received two scans (mean time interval, 20.5 months) including T1-weighted DCE-MR imaging, one with 0.5 M gadoterate meglumine and one with 1.0 M gadobutrol. Equimolar doses of gadolinium (0.1 mmol/kg body weight) were administered with identical injection speed (2 mL/s), resulting in differing gadolinium delivery rate. An identical region of interest (ROI_tz) within a BPH-node was identified on both scans. The area under the time-enhancement curve of each ROI_tz from 0 to 180 s post contrast arrival and pharmacokinetic parameters were calculated. Relative enhancement and signal-to-noise (SNR) and contrast-to-noise (CNR) ratios in the delayed phase at about 180 s were compared between both agents.

RESULTS

There was a significantly larger area under the time-enhancement curve (5.53 vs 4.97 p = 0.0007) and higher relative enhancement of BPH nodules (2.23 vs 1.96 p < 0.0001) with gadobutrol compared with gadoterate meglumine. There were no significant differences in SNR (44.55 vs 37.63 p = 0.12), CNR (31.22 vs 26.39 p = 0.18), and pharmacokinetic parameters Ktrans (0.31 vs 0.32 p = 0.86), Ve (1.36 vs 0.98 p = 0.13), and Kep (0.34 vs 0.36 p = 0.12).

CONCLUSIONS

At equimolar doses, increased gadolinium delivery over time using gadobutrol provides higher relative enhancement parameters in BPH nodules compared with gadoterate meglumine, but does not translate into improved SNR or CNR.

KEY POINTS

• At equal injection rate and equimolar total dose, gadobutrol compared with gadoterate meglumine provides a significantly greater relative enhancement in DCE-MR imaging of BPH over the first 180 s. • There are no significant differences in SNRs, CNRs, and pharmacokinetic parameters between the two GBCAs.

Advocating the Development of Next-Generation High-Relaxivity Gadolinium Chelates for Clinical Magnetic Resonance

The question of improved relaxivity, and potential efficacy therein, for a next-generation of magnetic resonance gadolinium chelates with extracellular distribution and renal excretion, which could also be viewed from the perspective of dose, is addressed on the basis of historical development, animal experimentation, and human trials. There was no systematic evaluation that preceded the choice of 0.1 mmol/kg as the standard dose for human imaging with the gadolinium chelates. In part, this dose was chosen owing to bloodwork abnormalities seen in phase I and phase II studies. Animal investigations and early clinical trials demonstrated improved lesion detectability at higher doses in the brain, liver, and heart. By designing an agent with substantially improved relaxivity, higher enhancement equivalent to that provided with the conventional gadolinium agents at high dose could be achieved, translating to improved diagnosis and, thus, clinical care. Implicit in the development of such high-relaxivity agents would be stability equivalent to or exceeding that of the currently approved macrocyclic agents, given current concern regarding dechelation and gadolinium deposition in the brain, skin, and bone with the linear agents that were initially approved. Development of such next-generation agents with a substantial improvement in relaxivity, in comparison with the current group of approved agents, with a 2-fold increase likely achievable, could lead to improved lesion enhancement, characterization, diagnosis, and, thus, clinical efficacy.

MRI Contrast Agents: Evolution of Clinical Practice and Dose Optimization

Accurate detection of lesions throughout the body is of paramount importance in contrast-enhanced magnetic resonance imaging (MRI). Optimal contrast agent performance is therefore of great importance and given the number of MRI contrast agent options today, this topic is of much ongoing study. The goal of this review article is to bring the read up to date on pertinent articles that relate to the evolution of radiological clinical practice and dose optimization pertaining to gadolinium contrast agents.

Effects of gadolinium-based contrast agent concentrations (0.5 M or 1.0 M) on the diagnostic performance of magnetic resonance imaging examinations: systematic review of the literature

Background To date there is no agreement as to what is the optimal concentration for gadolinium-based contrast agents (GBCAs). Purpose To assess whether diagnostic performance differences exist between 0.5 M and 1.0 M GBCAs used for magnetic resonance imaging (MRI). Material and Methods A PubMed literature search identified 21 clinical studies published between 2005 and 2013 which evaluated the diagnostic efficacy of both types of GBCAs. Study design, type of procedure, GBCA administration mode, imaging performances, impact on patient management, study limitations, and biases were analyzed. No statistical test was performed on pooled data. Results Sixteen comparative and five non-comparative studies were analyzed, involving 2183 patients who underwent MRI procedures for various indications. In 67% of the studies, 0.5 M and 1.0 M GBCAs were injected at equimolar gadolinium amounts per kg body weight. Only 33% applied the same molar flow rate for delivery of the GBCAs. No significant differences between GBCAs were reported for 23 out of 27 qualitative endpoints (mainly image quality, lesion, and vessel visualization) and 29 out of 40 quantitative endpoints. Three out of four studies with non-equimolar delivery rates showed better contrast-to-noise and signal-to-noise ratios for 1.0 M gadobutrol, without showing an impact on diagnostic performance. Methodological biases were identified in several studies impairing the interpretation of comparisons. Conclusion Imaging differences between 0.5 M and 1.0 M GBCAs were essentially observed under non-equimolar delivery rates. However, they did not result into greater diagnostic efficacy when performed under equimolar conditions.

Efficacy and Safety of Gadobutrol (1.0 M) versus Gadopentetate Dimeglumine (.5 M) for Enhanced Mri of Cns Lesions: A Phase Iii, Multicenter, Single-blind, Randomized Study in Chinese Patients

The aim of this study was to compare the efficacy and safety of macrocyclic gadobutrol (1.0 M) with linear gadopentetate dimeglumine (0.5 M) for contrast-enhanced magnetic resonance imaging (MRI) of central nervous system (CNS) lesions in Chinese patients (N = 147) with known or suspected CNS lesions, who were enrolled in this single-blind, randomized, parallel-group study. Three blinded independent readers evaluated all efficacy variables. The primary efficacy variable was the difference between the two agents for the change in contrast-to-noise ratio (CNR) between non-enhanced and contrast-enhanced scans of lesions. Secondary outcomes included mean change in number of lesions detected before and after contrast enhancement, diagnostic confidence, and safety and tolerability parameters. Gadobutrol was non-inferior to gadopentetate dimeglumine in respect to the difference in the mean change in CNR (6.94; 95% confidence interval [CI] lower limit: -3.90; predefined maximum 95% CI lower limit: -6.52). The mean change in the number of CNS lesions detected was greater with gadobutrol versus gadopentetate dimeglumine (1.2 vs. 0.2 lesions). Diagnostic confidence was classified as ‘high’ for more patients with gadobutrol versus gadopentetate dimeglumine by the investigators (58.8% vs. 55.4%) and by the three blinded readers (63.6% vs. 55.7%, 23.7% vs. 18.0% and 81.7% vs. 81.0%). Both agents were well tolerated by participating patients. We concluded that in Chinese patients with CNS lesions, gadobutrol (1.0 M) was as effective and well tolerated in contrast-enhanced MRI as gadopentetate dimeglumine (0.5 M). Gadobutrol provided improved visualization of CNS lesions compared with gadopentetate dimeglumine, with a comparable tolerability profile.