Why is a radioiodine treatment performed after surgery for thyroid cancer even though "everything has been removed"?
It is often not possible to remove the entire thyroid gland surgically, with the possibility of some remnants of thyroid tissue and some cancer cells left behind. In most cases, the lymph nodes are also surgically removed. As mentioned above, the most differentiated (papillary and follicular SD carcinomas) can be treated with radioiodine 4-6 weeks after surgery. During the first 4-6 weeks after the operation, thyroid hormones or iodine-containing preparations (e.g. iodine-containing X-ray contrast) should NOT be administered. . During this time a strong thyroid hormone deficiency will develop. The therapeutic radioiodine administered 4-6 weeks after the operation, can thus be intensively absorbed by the remaining thyroid cells, which are as a result irradiated and destroyed. If metastases are present, they are also partially or completely destroyed, depending on their ability of radioiodine uptake. If large metastases are detected by iodine accumulation, they may be surgically removed or additionally irradiated from outside.
