DIAGNOSIS OF CEREBRAL METASTASES BY MEANS OF STANDARD DOSES OF GADOBUTROL VERSUS A HIGH-DOSE PROTOCOL - INTRAINDIVIDUAL EVALUATION OF A PHASE-II HIGH-DOSE STUDY

Purpose: To assess the effectiveness and safety of normal and high dos es of Gadobutrol versus a standard dose of Gadolinium DTPA in the MR e valuation of patients with brain metastases. Material and methods: In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadob utrol, a new nonionic, low osmolality contrast agent. Each patient rec eived an initial injection of 0.1 mmol/kg body weight and an additiona l dose of 0.2 mmol/kg Gadobutrol 10 min later, Spin-echo images were o btained before and after the two applications of Gadobutrol. Dynamic s canning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intrai ndividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Result s: Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine che mistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiori ty of high-dose Gadobutrol injection in comparison to the standard dos e. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol, Qualitative delineation and contrast of the lesions increased significantly. The use of high- dose Gadobutrol improved the detection of 36 additional lesions in 6 p atients. Conclusion: The first in vivo results prove the excellent con trast capacity of the nonionic contrast agent Gadobutrol for the diagn osis of intracerebral metastases.