ASSESSMENT OF FEMALE FERTILITY AND CARCINOGENESIS AFTER I-131 THERAPYFOR DIFFERENTIATED THYROID-CARCINOMA

The aim of this study was to evaluate female fertility, carcinogenic, and genetic effects after treatment with I-131 of differentiated thyro id carcinoma. Methods: A total of 814 females of child-bearing age wer e studied. The fertility of 627 females who received I-131 therapy was compared to 187 untreated females. Birth histories of the children bo rn from these women were registered. The carcinogenic effect was evalu ated by comparing the incidence of tumors in 730 patients treated with I-131 with an internal control group, as well as with local populatio n incidence. Results: There was no significant difference in the ferti lity rate, birth weight and prematurity between the two groups. Only o ne case of a ventricular septal defect was observed in a child born to a woman treated with I-131. The overall standardized incidence ratio (SIR) of second tumors was 1.19 (95% cl:0.76-1.77) in patients treated with I-131. An elevated SIR was registered for salivary gland tumors and melanoma. No case of leukemia was registered. Conclusion: The risk of long-term effects of I-131 treatment of differentiated thyroid car cinoma is quite low. Iodine-131 may be safely used in treating cases w ith a high risk of recurrence.