[RI cisternography with 111-In-DTPA].

In contrast to 169Yb-DTPA the usage of 111In-DTPA, a new radiopharmaceutical, is not as yet popular for RI cisternography. This report deals with a comparative study of these two radiopharmaceuticals for RI cisternography. For the past one year 301 RI cisternography. For the past one year 301 RI cisternographies were performed in 160 cases at the Neurosurgical Survice of Shizuoka Rosai Hospital. Among those 169Yb-DTPA was used in 137 occasions, 111In-DTPA in 53, and both 169Yb-DTPA and 111In-DTPA in 30. The results of this study were as follow. 1. 111In-DTPA was chemically stable in intrathecal administration. 2. A reactive fever was minimal with 111In-DTPA if any. 3. There was no adverse reaction, such as aseptic meningitis, following 111In-DTPA cisternographies. 4. The effective half-life of 111In-DTPA was 16 hours, and that of 169Yb-DTPA 22 hours in this series. This means the men were exposed to radioactivity less with 111In-DTPA than with 169Yb-DTPA. 5. However, there was no difference in diagnostic value between these two radiopharmaceuticals, even 48 hours after intrathecal administration. From this study 111In-DTPA appears to be more suitable for RI cisternography than 169Yb-DTPA.