LEUKEMIA AFTER RADIOIODINE THERAPY FOR HYPERTHYROIDISM

Area of Science:

• Endocrinology
• Oncology
• Nuclear Medicine

Background:

• Hyperthyroidism is a common endocrine disorder.
• Radioiodine (I-131) therapy has been used for hyperthyroidism since the mid-20th century.
• The potential long-term effects of radioiodine therapy, including secondary malignancies like leukemia, warrant investigation.

Purpose of the Study:

• To investigate the occurrence of leukemia in patients treated with radioiodine for hyperthyroidism.
• To assess any potential association between radioiodine therapy and leukemia development.

Main Methods:

• Retrospective analysis of 650 hyperthyroidism patients treated with radioiodine (I-131) between 1945 and 1961.
• Monitoring for the development of leukemia in the patient cohort over time.

Main Results:

• Two cases of leukemia were observed in the cohort.
• One patient developed chronic lymphatic leukemia three years post-therapy.
• Another patient developed acute or subacute myelomonocytic leukemia 14 years post-therapy.

Conclusions:

• The observed leukemia cases do not establish a causal relationship with radioiodine therapy.
• The incidence of leukemia in this cohort may be attributable to natural occurrence rates.
• Further long-term studies are needed to fully understand the risks associated with radioiodine therapy.