Abstract:
Background and aim of study: Differentiated thyroid carcinoma and thyrotoxicosis are commonly diagnosed in women in their reproductive years. In fact, 37% of women diagnosed with thyroid cancer are younger than 45 years of age. Gonadal germ cells are very vulnerable to radiotherapy. Following RAI treatment, retrospective studies have reported an 18-48 months earlier age at menopause. However, despite these reports, the full impact of RAI treatment on gonadal reserve has never been systematically studied. The aim of this study is to prospectively evaluate the effect of RAI therapy on ovarian reserve as assessed by the level of anti-Mullerian hormone (AMH), a common tool in the evaluation of women who present for fertility treatment.
Study Design: This prospective study aims at enrolling 30 patients, between the ages of 18-45 years, who are scheduled to undergo RAI treatment. Baseline evaluation includes a complete reproductive history and physical examination. Subjects with previous history of pelvic surgery or irradiation are excluded. Serum AMH, estradiol and gonadotropins are assessed at baseline, and subsequently every 3 months for a year following RAI treatment. While each subject serves as her own control, AMH levels will also be compared to the expected decline over time.
Preliminary Results: Ten patients, aged 20-40 have been enrolled in the study so far. All had experienced menarche between the ages of 11 and 12 years, and reported regular menstrual periods before treatment. Five women had borne children. Seven women received RAI for papillary thyroid cancer (all StageI) at doses between 30-150 mCi. Three patient received treatment for Graves' disease (10-18 mCi). The levels of AMH in the patients before the RAI treatment were 1.3 – 6.9 ng/ml. At 3 months, they decreased by more than 50% in 2 patients who received 150 mCi RAI (from 5.9±1.3 to 2.0±0.06). Additional data will be available shortly.
Conclusions: If confirmed, these preliminary data would suggest an early deleterious effect of RAI on ovarian reserve. This could potentially affect treatment decision particularly in young women with thyroid cancer.
Nothing to Disclose: IY, FA, RL, SS, NS, OG, KMT, EO