Thyroid uptake of 67Ga-citrate is associated with thyroid autoimmunity and hypothyroidism in patients with sarcoidosis.

PURPOSE

To evaluate the association of gallium-67 ((67)Ga)-citrate thyroid uptake with the presence of thyroid disorders in patients with sarcoidosis (S patients).

METHODS

Eighty-four S patients were evaluated by a complete thyroid work-up (neck ultrasound, circulating thyroid hormones and anti-thyroid antibodies, fine-needle aspiration).

RESULTS

In S patients with (67)Ga thyroid uptake (respect those without): serum thyroid-stimulating hormone, the titre of anti-thyroid peroxidase (AbTPO) and/or anti-thyroglobulin antibodies (AbTg), and the prevalence of S patients with hypothyroidism or with positive AbTg or AbTPO was significantly higher; a thyroid hypoechoic pattern was more frequent. The prevalence of thyroid nodules was not significantly different between the two groups. Two cases of papillary thyroid cancer were observed in S patients without (67)Ga thyroid uptake, whilst no case in those with (67)Ga thyroid uptake.

CONCLUSIONS

(67)Ga thyroid uptake is associated with the presence of aggressive autoimmune thyroiditis and hypothyroidism in S patients; thyroid function and ultrasonography should be performed in the presence of (67)Ga thyroid uptake.