Radioidine therapy temporarily increases circulating endothelial cells and decreases endothelial progenitor cells.

ABSTRACT

BACKGROUND: Radiotherapy can cause vascular injury. No data on radioiodine therapy and vascular damage are available. MATERIAL AND METHODS: We examined the number of circulating endothelial cells (CEC) and circulating endothelial progenitor cells (CEPC) before therapy 1, 2, 3 and 5 days as well as 1, 2, 3, 4, 6, 8, 10, and 12 weeks after therapy with (131)I at doses ranging from 5-200 mCi. The individual number of CEC and CEPC is associated with the presence of risk factors. RESULTS: Irrespective of prevalues, CEC exhibited a significant dose-dependent temporary increase reaching the maximum in weeks 1 and 2. In contrast, CEPC show a decrease at the same time. CONCLUSIONS: These results indicate that (131)I-therapy induces a dose-dependent radiation injury at the vascular wall level enhancing endothelial desquamation and reducing reendothelialization and thereby a proatherogenic stage. The clinical consequence of these findings still needs to be assessed.