[Clinical evaluation of 123I-orthoiodohippurate (123I-OIH) for diagnosis of renal function: dose finding study]

The safety, clinical usefulness and the optimal dose of 123I-orthoiodohippurate (123I-OIH) were evaluated in patients with mild renal disorders. 123I-OIH was administered intravenously to 45 patients, and 39 of those patients were analyzed for the clinical usefulness. The numbers of cases analyzed were 10 for 9.25 MBq (0.25 mCi), 18.5 MBq (0.5 mCi) and 74 MBq (2.0 mCi) and 9 for 37 MBq (1.0 mCi). Neither adverse reaction nor abnormal laboratory findings due to 123I-OIH administration were observed in the 45 patients. The clinical usefulness of the drug was evaluated in terms of individual renal function, regional renal functions, renal blood flow, parenchymal function and urinary function, and ability to differentiate between the renal and urinary functions, and the overall clinical usefulness. In the evaluation by the investigators, there were no significant differences in each of these parameters among any of the doses administered. In the evaluation by the Committee, however, the usefulness with 74 MBq superior to those with 9.25 MBq and 18.5 MBq, while there was no significant differences between those with 37.5 MBq and 74 MBq. The qualities of the blood flow phase images, functional phase images, functional images, and the statistical noises of the individual and the regional kidney renograms were also evaluated by the Committee. The image qualities and the statistical noises with 37 MBq were superior to those with 9.25 MBq and 18.5 MBq except for the functional image quality, and there were no significant differences between those with 37 MBq and 74 MBq other than the regional renograms and the functional images, which were superior with 74 MBq.(ABSTRACT TRUNCATED AT 250 WORDS)