Pediatric renal iodine-123 orthoiodohippurate dosimetry

Radiation exposure to the kidney from iodine-123 orthoiodohippurate ([123I]OIH) and any associated [124I]OIH contamination may vary by a factor of several hundred depending upon the health of the kidney. Calculations of kidney dose were made for patients with the following renal states: normal, acute tubular necrosis (ATN), obstruction, and renal transplant. The dosimetry was based on a minimum practical administered activity (MPAA) of 200 microCi for pediatric patients and 500 microCi for adults. High-grade obstruction of recent onset and severe ATN are the only disease processes which could result in high exposures, and this is due primarily to the contribution of 124I. For selected cases, OIH labeled with pure 123I should be very seriously considered.