The TRUTH confirmed: validation of an intraindividual comparison of gadobutrol and gadoteridol for imaging of glioblastoma using quantitative enhancement analysis.

BACKGROUND: Previous intraindividual comparative studies evaluating gadobutrol and gadoteridol for contrast-enhanced magnetic resonance imaging (MRI) of brain tumours have relied on subjective image assessment, potentially leading to misleading conclusions. We used artificial intelligence algorithms to objectively compare the enhancement achieved with these contrast agents in glioblastoma patients. METHODS: Twenty-seven patients from a prior study who received identical doses of 0.1 mmol/kg gadobutrol and gadoteridol (with appropriate washout in between) were evaluated. Quantitative enhancement (QE) maps of the normalised enhancement of voxels, derived from computations based on the comparison of contrast-enhanced T1-weighted images relative to the harmonised intensity on unenhanced T1-weighted images, were compared. Bland-Altman analysis, linear regression analysis and Pearson correlation coefficient (r) determination were performed to compare net QE and per-region of interest (per-ROI) average QE (net QE divided by the number of voxels). RESULTS: No significant differences were observed for comparisons performed on net QE (mean difference -24.37 ± 620.8, p = 0.840, r = 0.989) or per-ROI average QE (0.0043 ± 0.0218, p = 0.313, r = 0.958). Bland-Altman analysis revealed better per-ROI average QE for gadoteridol-enhanced MRI in 19/27 (70.4%) patients although the mean difference (0.0043) was close to zero indicating high concordance and the absence of fixed bias. CONCLUSIONS: The enhancement of glioblastoma achieved with gadoteridol and gadobutrol at 0.1 mmol/kg bodyweight is similar indicating that these agents have similar contrast efficacy and can be used interchangeably, confirming the results of a prior double-blind, randomised, intraindividual, crossover study.

Dose-Lowering in Contrast-Enhanced MRI of the Central Nervous System: A Retrospective, Parallel-Group Comparison Using Gadobenate Dimeglumine.

BACKGROUND: Concerns over gadolinium (Gd) retention encourage the use of lower Gd doses. However, lower Gd doses may compromise imaging performance. Higher relaxivity gadobenate may be suited to reduced dose protocols. PURPOSE: To compare 0.05 mmol/kg and 0.1 mmol/kg gadobenate in patients undergoing enhanced MRI of the central nervous system (CNS). STUDY TYPE: Retrospective, multicenter. POPULATION: Three hundred and fifty-two patients receiving 0.05 (n = 181) or 0.1 (n = 171) mmol/kg gadobenate. FIELD STRENGTH/SEQUENCES: 1.5 T and 3.0 T/precontrast and postcontrast T1-weighted spin echo/fast spin echo (SE/FSE) and/or gradient echo/fast field echo (GRE/FFE); precontrast T2-weighted FSE and T2-FLAIR. ASSESSMENT: Images of patients with extra-axial lesions at 1.5 T or any CNS lesion at 3.0 T were reviewed by three blinded, independent neuroradiologists for qualitative (lesion border delineation, internal morphology visualization, contrast enhancement; scores from 1 = poor to 4 = excellent) and quantitative (lesion-to-brain ratio [LBR], contrast-to-noise ratio [CNR]; SI measurements at regions-of-interest on lesion and normal parenchyma) enhancement measures. Noninferiority of 0.05 mmol/kg gadobenate was determined for each qualitative endpoint if the lower limit of the 95% confidence interval (CI) for the difference in precontrast + postcontrast means was above a noninferiority margin of -0.4. STATISTICAL TESTS: Student's t-test for comparison of mean qualitative endpoint scores, Wilcoxon signed rank test for comparison of LBR and CNR values; Wilcoxon rank sum test for comparison of SI changes. Tests were significant for P < 0.05. RESULTS: The mean change from precontrast to precontrast + postcontrast was significant for all endpoints. Readers 1, 2, and 3 evaluated 304, 225, and 249 lesions for 0.05 mmol/kg gadobenate, and 382, 309, and 298 lesions for 0.1 mmol/kg gadobenate. The lower limit of the 95% CI was above -0.4 for all comparisons. Significantly, higher LBR and CNR was observed with the higher dose. DATA CONCLUSION: 0.05 mmol/kg gadobenate was noninferior to 0.1 mmol/kg gadobenate for lesion visualization. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Contrast-enhanced MR mammography: improved lesion detection and differentiation with gadobenate dimeglumine.

OBJECTIVE: The objective of our study was to intraindividually compare 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine for contrast-enhanced breast MRI. SUBJECTS AND METHODS: Forty-seven women (mean age +/- SD, 50.8 +/- 12.9 years) with breast lesions classified as BI-RADS category 3, 4, or 5 for suspicion of malignancy underwent two identical MR examinations at 1.5 T separated by 48-72 hours. T1-weighted gradient-echo images were acquired before contrast administration and at 2-minute intervals after the randomized injection of gadopentetate dimeglumine or gadobenate dimeglumine at 2 mL/s. Two blinded readers evaluated randomized image sets for lesion detection and differentiation as benign or malignant compared with histology. The McNemar exact test and the generalized estimating equation (GEE) were used to compare lesion detection rates and diagnostic performance in terms of sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: Histopathology data were available for 78 lesions. Significantly more lesions overall (75/78 [96%] vs 62/78 [79%], respectively; p = 0.0002) and significantly more malignant lesions (49/50 [98%] vs 38/50 [76%]; p = 0.0009) were detected with gadobenate dimeglumine than gadopentetate dimeglumine. All detected malignant lesions were correctly diagnosed with both agents. More detected benign lesions were correctly diagnosed with gadobenate dimeglumine than with gadopentetate dimeglumine (20/26 [77%] vs 17/24 [71%], respectively). Differentiation of lesions was significantly (p = 0.0001) better with gadobenate dimeglumine. Significantly better diagnostic performance was noted with gadobenate dimeglumine than with gadopentetate dimeglumine, respectively, for sensitivity (98.0% vs 76.0%; p = 0.0064), accuracy (88.5% vs 69.2%; p = 0.0004), PPV (86.0% vs 76.0%; p = 0.0321), and NPV (95.2% vs 57.1%; p = 0.0003). CONCLUSION: Lesion detection and malignant-benign differentiation is significantly better with 0.1 mmol/kg gadobenate dimeglumine than 0.1 mmol/kg gadopentetate dimeglumine.

Enhancing lesions of the brain: intraindividual crossover comparison of contrast enhancement after gadobenate dimeglumine versus established gadolinium comparators.

RATIONALE AND OBJECTIVES: Gadobenate dimeglumine (Gd-BOPTA) possesses a two-fold higher T1 relaxivity compared to other available gadolinium contrast agents. The study was conducted to evaluate the benefits of this increased relaxivity for MR imaging of intracranial enhancing brain lesions. MATERIALS AND METHODS: Forty-five patients (31 males, 14 females) with suspected glioma or cerebral metastases were evaluated. Patients received Gd-BOPTA and either Gd-DTPA (n = 23) or Gd-DOTA (n = 22) in fully randomized order at 0.1 mmol/kg body weight and at a flow rate of 2 ml/s. The second agent was administered 1-14 days after the first agent. Images were acquired precontrast (T1wSE, T2wFSE sequences) and at sequential postcontrast time-points (T1wSE sequences at 0, 2, 4, 6, and 8 and 15 min and a T1wSE-MT sequence at 12 min) at 1.0 or 1.5 T using a head coil. Determination of contrast enhancement was performed quantitatively (lesion-to-brain ratio, contrast-to-noise ratio, and percent enhancement) and qualitatively (border delineation, internal morphology, contrast enhancement, and diagnostic preference) by two independent, fully blinded readers. RESULTS: Images from 43/45 patients were available for quantitative assessment. After correction for precontrast values, significantly greater lesion-to-brain ratio (P < .003), contrast-to-noise ratio (P < .03), and percent enhancement (P < .0001) was noted by both readers for Gd-BOPTA-enhanced images at all time-points from 2 min postcontrast. Qualitative assessment of all patients similarly revealed significant preference for Gd-BOPTA for lesion border delineation (P < .004), lesion internal morphology (P < .008), contrast enhancement (P < .0001), and diagnostic preference (P < .0005). CONCLUSIONS: The greater T1 relaxivity of Gd-BOPTA permits improved visualization of intracranial enhancing lesions compared to conventional gadolinium agents.

Comparison of gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for enhanced MR imaging of brain and spine tumours in children.

BACKGROUND: Gadobenate dimeglumine (Gd-BOPTA) demonstrates superior enhancement of brain tumours in adult patients than Gd-DTPA. OBJECTIVE: To determine whether Gd-BOPTA has advantages over Gd-DTPA for enhanced MR imaging of paediatric brain and spine tumours. MATERIALS AND METHODS: Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed. RESULTS: Pre-dose to post-dose changes in lesion visualization were significantly better for Gd-BOPTA for both lesion level (2.68+/-2.17 vs. 1.05+/-1.90, P=0.0106) and patient level (2.55+/-2.18 vs. 1.14+/-1.68, P=0.0079) comparisons. The mean pre-dose to post-dose change in CNR was greater for Gd-BOPTA (9.13+/-15.36) than Gd-DTPA (2.18+/-9.90), but the difference was only marginally significant (P=0.0779; 95% CI: -0.553, 14.454) because of wide variations of signal intensity between lesions. Similar findings were obtained for LBR and per cent enhancement. No differences between the agents were noted in terms of safety parameters. CONCLUSIONS: At an equivalent dose Gd-BOPTA is significantly better than Gd-DTPA for visualization of enhancing CNS tumours in paediatric patients.

Gadobenate dimeglumine-enhanced MRI of the breast: analysis of dose response and comparison with gadopentetate dimeglumine.

OBJECTIVE: The purpose of this study was to evaluate the clinical efficacy and dose response relationship of three doses of gadobenate dimeglumine for MRI of the breast and to compare the results with those obtained after a dose of 0.1 mmol/kg of body weight of gadopentetate dimeglumine. SUBJECTS AND METHODS. Gadobenate dimeglumine at 0.05, 0.1, or 0.2 mmol/kg of body weight or gadopentetate dimeglumine at 0.1 mmol/kg of body weight was administered by IV bolus injection to 189 patients with known or suspected breast cancer. Coronal three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 min after the administration of the dose. Images were evaluated for lesion presence, location, size, morphology, enhancement pattern, conspicuity, and type. Lesion signal intensity-time curves were acquired, and lesion matching with on-site final diagnosis was performed. A determination of global lesion detection from unenhanced to contrast-enhanced and combined images was performed, and evaluations were made of the diagnostic accuracy for lesion detection and characterization. A full safety evaluation was conducted. RESULTS: Significant dose-related increases in global lesion detection were noted for patients who received gadobenate dimeglumine (p < 0.04, all evaluations). The sensitivity for detection was comparable for 0.1 and 0.2 mmol/kg of gadobenate dimeglumine, and specificity was highest with the 0.1 mmol/kg dose. Higher detection scores and higher sensitivity values for lesion characterization were found for 0.1 mmol/kg of gadobenate dimeglumine compared with 0.1 mmol/kg of gadopentetate dimeglumine, although more variable specificity values were obtained. No differences in safety were observed, and no serious adverse events were reported. CONCLUSION: Gadobenate dimeglumine is a capable diagnostic agent for MRI of the breast. Although preliminary, our results suggest that 0.1 mmol/kg of gadobenate dimeglumine may offer advantages over doses of 0.05 and 0.2 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadopentetate dimeglumine for breast lesion detection and characterization.