Safety of 125iodine and 192iridium implants to the canine carotid artery. Long-term results.

Thirty-nine healthy dogs underwent a simulated radical neck dissection followed by implantation of either 125Iodine (125I) or 192Iridium (192Ir) in various dose regimes randomized prospectively from 3,000 to 30,000 rad. Bilateral selective carotid angiography was performed immediately postoperatively and at 6, 12, 18, and 24 months. No significant effects occurred to the animals who received 15,000 rad 125I or 6,000 rad 192Ir. In the higher dosed animals the 125I-treated group fared better than the 192Ir-treated group, probably due to the lower dose rate delivery. Fewer and less serious complications occurred in the 125I-treated group, but this group developed more complications after one year than the Iridium group.