The Dose of Radioactive Iodine Needed to Ablate the Thyroid Remnant Left Behind After Thyroidectomy
Status:
Unknown status
Trial end date:
2020-09-01
Target enrollment:
Participant gender:
Summary
The thyroid cells take up iodine, and radioactive iodine is commonly used to irradiate
residual thyroid tissue and thyroid cancer following surgical removal of the thyroid gland
(thyroidectomy). A whole body radioactive iodine scanning is usually carried out after
thyroidectomy to assess the amount of thyroid tissue left behind at surgery (that might still
contain cancer), and to evaluate the presence of iodine avid lesions elsewhere in the body
(that might be cancer metastases). A large dose of radioactive iodine is often given, still
the optimal iodine dose to ablate the thyroid remnant after surgery is not known. In this
study, two radioactive iodine doses are compared in the ablation of the thyroid remnant, a
smaller (1110 MBq) dose and a larger (3700 MBq) dose. The study participants are randomly
allocated using a 1:1 ratio to receive either the smaller or the larger radioactive iodine
dose. These treatments are compared for safety, adverse effects, and the need for subsequent
repeat treatments. The individual absorbed radiation doses are measured. The study hypothesis
is that fewer repeat radioiodine treatments might be needed after the larger dose, but the
larger dose might be associated with a higher frequency of adverse events.