Patient exposure when using 99Tcm-DTPA for evaluation of cerebrospinal fluid shunt patency.

The absorbed dose from 99Tcm-DTPA was estimated from 12 investigations in 9 patients who were evaluated for the patency of ventriculo-peritoneal shunts. The distribution of 99Tcm-DTPA in the ventricles, urinary bladder and peritoneal cavity was determined in regions of interest from repeated static gamma camera images. The effective dose equivalent was calculated to be less than 0.10 mSv for an injected activity of 15 MBq.