Ovarian function after radioiodine therapy in patients with thyroid cancer.
OBJECTIVE
To assess ovarian function in young women treated with radioiodine.


METHODS
The study was conducted on 50 women with thyroid carcinoma aged less than 40 years (mean, 29.8 years), with regular menstrual cycles and normal FSH levels prior to radioiodine therapy. FSH determination was repeated 6 and 12 months after radioiodine therapy (mean, 4.24 GBq iodine-131) and menstrual cycles were monitored during this period.


RESULTS
Twenty percent of the patients reported amenorrhea during the first year. FSH levels increased after 6 months (from 5.1 +/- 1.8 to 10.6 +/- 2.2 IU/l, p < 0.00 001) and 28 % of the patients showed elevated values, which had returned to normal by the end of the first year.


CONCLUSIONS
Radioiodine causes transitory alterations in ovarian function even in younger women and after a mean activity of 4.2 GBq (115 mCi).
Nuclear Medicine and Endocrinology Service, Santa Casa de Belo Horizonte, Minas Gerais, Brazil. pedrorosario@globo.com.br
P W
PW
Souza Rosário
T
T
Alvarenga Fagundes
A S
AS
Villas-Boas Fagundes
A L
AL
Barroso
L
L
Lamego Rezende
E
E
Lanza Padrão
V C
VC
Guimarães
A C
AC
Horta
M
M
Franco
S
S
Purisch
D000328:Adult; D002277:Carcinoma / Q000097:blood / Q000532:radiotherapy*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D008597:Menstrual Cycle / Q000502:physiology / Q000528:radiation effects; D010053:Ovary / Q000502:physiology / Q000528:radiation effects*; D013964:Thyroid Neoplasms / Q000097:blood / Q000532:radiotherapy*
D007457:Iodine Radioisotopes; D005640:Follicle Stimulating Hormone