Isotope therapy is one of the methods used in primary hyperthyroidism.
The therapy is based on short-range beta radiation
emitted from radioactive iodine. Radioiodine administration
must always be preceded by pharmacological normalization
of thyroid function. Otherwise, post-radiation thyrocyte destruction
and thyroid hormones release may lead to hyperthyroidism
exacerbation.
Indications for radioiodine therapy in Graves-Basedow disease
include recurrent hyperthyroidism after thyrostatic treatment
or thyroidectomy and side-effects observed during thyrostatic
treatment.
In toxic nodule, isotope therapy is the first choice therapy. Radioiodine
is absorbed only in autonomous nodule. Therefore,
it destroys only this area and does not damage the remaining
thyroid tissue.
In toxic goitre, radioiodine is used mostly in recurrent nodules.
Absolute contraindications for radioiodine treatment are pregnancy
and lactation. Relative contraindications are thyroid nodules suspected of malignancy and age under 15 years. In
patients with thyroid nodules suspected of malignancy, radioiodine
treatment may be applied as a preparation for surgery, if
thyrostatic drugs are ineffective or contraindicated. In children,
radioiodine therapy should be considered in recurrent toxic
goitre and when thyrostatic drugs are ineffective.
In patients with Graves-Basedow disease and thyroid-associated
orbitopathy, radioiodine treatment may increase the inflammatory
process and exacerbate the ophthalmological symptoms.
However, thyroid-associated orbitopathy cannot be considered
as a contraindication for isotope therapy.
The potential carcinogenic properties of radioiodine, especially
associated with tissues with high iodine uptake (thyroid, salivary
glands, stomach, intestine, urinary tract, breast), have not been
confirmed.
Nuclear Med Rev 2011; 14, 1: 29–3