Detection of Intracranial Metastases

Abstract

To compare gadobenate dimeglumine (MultiHance) with other commercially available MRI contrast agents for the detection of intracranial metastases. A retrospective assessment was performed on MR images from 22 patients enrolled in a prior phase II clinical trial of gadobenate dimeglumine. Each patient underwent two examinations: a first examination with one of three "comparator" agents (gadopentetate dimeglumine, gadodiamide, and gadoterate meglumine) at a dosage of either 0.1 or 0.2 mmol/kg, and then a similar examination with gadobenate dimeglumine at equal dosage. All images were evaluated randomly for lesion number and location in unpaired and then paired fashion by two independent, masked neuroradiologists. A third assessor performed quantitative assessments on the available complete sets of digitally recorded images (10 cases). The findings for the comparator agents were pooled. Sensitivity for lesion detection with gadobenate dimeglumine (93%-100%) was markedly superior to that of comparator-enhanced examinations (65%-73%). The increase of lesion-to-brain contrast of the main lesion was consistently greater with gadobenate dimeglumine than with comparator agents relative to unenhanced contrast (+43% vs. +27%). Gadobenate dimeglumine proved to be a more efficacious agent than comparator contrast agents for the detection of intracranial metastatic lesions: superior efficacy was noted by both reviewers for total lesion count as well as for sensitivity and positive predictive value for lesion detection. The higher relaxivity of gadobenate dimeglumine might explain the superior sensitivity of gadobenate dimeglumine-enhanced MRI for the detection of central nervous system metastases.