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- Hahn, Gabriele, et al.
(författare)
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Pharmacokinetics and safety of gadobutrol-enhanced magnetic resonance imaging in pediatric patients
- 2009
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Ingår i: Investigative Radiology. - 0020-9996 .- 1536-0210. ; 44:12, s. 776-783
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This clinical study investigated the pharmacokinetics and safety of gadobutrol, a magnetic resonance (MR) imaging extracellular contrast agent, in pediatric patients aged 2 to 17 years. MATERIALS AND METHODS: In this open-label, multicenter study, patients scheduled for routine contrast-enhanced MR imaging of the brain, spine, liver or kidney, or MR angiography received a single intravenous injection of gadobutrol (0.1 mmol/kg/0.1 mL/kg). Patients were stratified by age groups (2-6, 7-11, and 12-17 years). Blood and urine samples were collected at prespecified time points and analyzed for gadolinium concentrations. Plasma data were evaluated by means of a nonlinear mixed effects model, and urine data were analyzed using descriptive statistics. In addition, the safety of gadobutrol was evaluated. RESULTS: A total of 130 patients (2-6 years, n = 45; 7-11 years, n = 39; 12-17 years, n = 46) were included in the final population pharmacokinetic analysis. Gadobutrol pharmacokinetics in children aged 2 to 17 years were adequately described by an open 2-compartment model with elimination from the central compartment. The median estimates (2.5th percentile, 97.5th percentile) of body weight-normalized total body clearance (L/h/kg) per age group were 0.10 (0.05, 0.17) for all ages, 0.13 (0.09, 0.17) in the 2 to 6 year age group, 0.10 (0.05, 0.17) in the 7 to 11 year age group and 0.09 (0.05, 0.10) in the 12 to 17 year age group. The body weight-normalized median estimates of total volume of distribution (L/kg) were 0.20 (0.12, 0.28) for all ages, 0.24 (0.20, 0.28) in the 2 to 6 year age group, 0.19 (0.14, 0.23) in the 7 to 11 year age group and 0.18 (0.092, 0.23) in the 12 to 17 year age group. Median gadolinium plasma concentrations at 20 minutes postinjection were simulated using the population pharmacokinetic model and ranged from 414 (13 kg subject) to 518 micromol/L (65 kg subject). Body weight was identified as the major covariate influencing the pharmacokinetic parameters of total body clearance and central volume of distribution. Age was not found to be an additional independent parameter. The median amount of renally excreted gadolinium was 77.0% of the administered dose within 6 hours postinjection, indicating that gadobutrol was renally excreted in this pediatric population aged 2 to 17 years. Gadobutrol was well tolerated, with drug-related adverse events of mild intensity reported for 8 (5.8%) of 138 patients. CONCLUSIONS: Observed differences in pharmacokinetics were attributed to body weight, with no additional independent effect of age. Thus, no dose adjustment from the standard dose of gadobutrol in adults based on body weight (0.1 mmol/kg) is necessary in pediatric patients aged 2 to 17 years. Gadobutrol was safe and well tolerated in the pediatric population in this study.
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| 2. |
- van der Beek, Justine N., et al.
(författare)
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MRI Characteristics of Pediatric Renal Tumors : A SIOP-RTSG Radiology Panel Delphi Study
- 2022
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Ingår i: Journal of Magnetic Resonance Imaging. - : Wiley. - 1053-1807 .- 1522-2586. ; 55:2, s. 543-552
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Tidskriftsartikel (refereegranskat)abstract
- Background: The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. Purpose: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. Study Type: Consensus process using a Delphi method. Population: Not applicable. Field Strength/Sequence: Abdominal MRI including T1- and T2-weighted imaging, contrast-enhanced MRI, and diffusion-weighted imaging at 1.5 or 3 T. Assessment: Twenty-three radiologists from the SIOP-RTSG radiology panel with ≥5 years of experience in MRI of pediatric renal tumors and/or who had assessed ≥50 MRI scans of pediatric renal tumors in the past 5 years identified potentially discriminatory characteristics in the first questionnaire. These characteristics were scored in the subsequent second round, consisting of 5-point Likert scales, ranking- and multiple choice questions. Statistical Tests: The cut-off value for consensus and agreement among the majority was ≥75% and ≥60%, respectively, with a median of ≥4 on the Likert scale. Results: Consensus on specific characteristics mainly concerned the discrimination between WTs and non-WTs, and WTs and nephrogenic rest(s) (NR)/nephroblastomatosis. The presence of bilateral lesions (75.0%) and NR/nephroblastomatosis (65.0%) were MRI characteristics indicated as specific for the diagnosis of a WT, and 91.3% of the participants agreed that MRI is useful to distinguish NR/nephroblastomatosis from WT. Furthermore, all participants agreed that age influenced their prediction in the discrimination of pediatric renal tumors. Data Conclusion: Although the discrimination of pediatric renal tumors based on MRI remains challenging, this study identified some specific characteristics for tumor subtypes, based on the shared opinion of experts. These results may guide future validation studies and innovative efforts. Level of Evidence: 3. Technical Efficacy Stage: 3.
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