Answer:
The thyroid gland absorbs almost all of the iodine in the body. When radioactive iodine (RAI), also known as I-131, is given to the body as a liquid or capsule, it becomes concentrated in thyroid cells. Radiation can kill the thyroid gland and any other thyroid cells or tissues (including cancer cells) that absorb iodine, without damaging any other organs.
Step-by-step explanation:
The thyroid gland is an organ that belongs to the endocrine system and its function is to synthesize hormones that are responsible for controlling the body's metabolism, this gland has an important characteristic and that is that the hormones it produces have a unique chemical composition due to They are the only hormones that contain iodine in their structure, this in turn is essential for its functioning because the body does not synthesize it and it must be consumed in the diet. When a small dose of the radiopharmaceutical iodine 131 (Sodium Iodide 131I) is consumed, it is absorbed into the bloodstream and concentrated by the thyroid gland, where it begins to destroy cancer cells in the gland. 131I quickly attaches itself to thyroid cells to destroy them, but continues to emit radioactivity for a long time: it takes 8 days to halve. The beta radiation particles of 131I, which we call radioiodine or radioactive iodine, have a range of 2mm and act for a long time in a constant way. Fortunately, the body's metabolism quickly expels iodine through the urine, so that in one day the amount of iodine has decreased considerably.