[Radiopharmaceuticals in kidney diagnosis]

Abstract

Nuclear medicine is potentially of great value in assessing renal function. Due to the many simple methods which have been proposed and new developments in renal radiopharmaceuticals and computer software, quick, reliable and precise answers to questions from clinicians are possible. Depending on the needs and infrastructure of each clinic, and due to specific renal radiopharmaceuticals combined with the simplicity of radioactivity measurements, plasma clearance can be obtained from one or two plasma samples within 45 minutes with good accuracy. More widely used methods require the gamma camera, which gives the same functional results but, besides the global function, split renal function is obtainable. Today we have radiopharmaceuticals which are well validated. They measure functional parameters such as glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF). Others can be used to give morphological information. The recently developed drugs can be labeled with Tc-99m, work-horse of the nuclear medicine physician. This radionuclide combines optimal physical properties (ideal gamma energy [140 keV]), no beta emission, short half life (6 h) and consequent low radiation dose to the patient) with low cost and permanent availability. Of the many agents cleared by GFR, two are mainly used in the clinic (chromium-51-EDTA and Tc-99m-DTPA). The first agent is very reliable due to its radiochemical and biological properties, but only the latter can be used when imaging is required. Two agents which are actively secreted by the renal tubules are available for the estimation of ERPF: radioiodinated ortho-iodohippurate (OIH) as radioactively labeled analog of the classic agent para-aminohippurate (PAH), and the new drug Tc-99m-mercaptoacetyltriglycine (MAG3).(ABSTRACT TRUNCATED AT 250 WORDS)