Chromosome Aberrations after Treatment with Radioactive Iodine for Thyroid Cancer

Abstract

The study aimed to investigate whether the determination of chromosome aberrations in circulating blood lymphocytes could be useful to assess whole-body exposure from radioactive iodine released accidentally. Ten patients treated with two doses of 1850 MBq of 131I given 24 h apart for thyroid cancer were studied for chromosome aberrations (dicentrics) in blood samples taken before and at various times after exposure. The increase in the yield of aberrations caused by the exposure to iodine was small but statistically significant. Compared to published values for whole-body doses after such treatment, this increase appears to be somewhat smaller than expected from dose-effect relationships obtained for an acute exposure of lymphocytes in vitro or in vivo, a fact which could be explained by the low dose rate of the 131I exposure. Thus, in situations where a population was exposed as a result of the release of radioactive iodine, a determination of chromosome aberrations in blood lymphocytes would not appear to be very useful to determine exposure from iodine.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

“…Therefore, it is important to allow for recovery of bone marrow between 131 I treatments. In support of these clinical observations, 131 I has been shown in peripheral lymphocytes to induce a significant increase in the number of dicentric chromosomes (275)(276)(277), and the aberrations of chromosomes 1, 4, and 10 are not only more prevalent but are still apparent after 4 years (276). A recent report comparing thyroid hormone withdrawal to rhTSH suggests a lower frequency of lymphocyte chromosomal rearrangements after 131 I dosing using rhTSH preparation (278).…”

Chromosome aberrations after high-dose 131I and 99mTc-MIBI administration using a micronucleus assay

“…Watanabe et al [10] reported that the incidence of micronuclei has been elevated as a consequence of 131 I exposure. Baugnet-Mahieu et al [8] reported a small but significant increase in chromosomal aberration in the lymphocytes of patients with thyroid cancer treated with 1850 MBq of 131 I for 24 h.…”

“…It has earlier been shown that 99m Tc-MIBI is particularly accumulated in peripheral blood lymphocytes, which are recognized to be extremely vulnerable to radiopharmaceuticals [7]. There are also reports in which 131 I has resulted in increased micronuclei incidence in peripheral lymphocytes [8][9][10].…”

Evaluation the Synergistic Effect of High Dose Radiation of Radioiodine on the Immune System Suppressed By Cyclosporine

“…So far, there have been many studies on the biological damages after radioiodine treatment, however, there are very few reports regarding the effects of radiation emitted by radioactive iodine on the immune system (Baugnet-Mahieu et al, 1994).…”