How does nuclear medicine cure diseases? Can anyone give an example of how nuclear medicine is used to cure diseases? I don't understand how it works.

The. The best example of how nuclear medicine is used to cure diseases is treatment of thyroid cancer or graves' disease (a form of hyperthyroidism). In both cases the goal is to destroy thyroid tissue. The thyroid gland contains a large amount of iodine which it uses to produce thyroid hormone. Once iodine is ingested, a large amount is concentrated within the thyroid gland. Nuclear medicine harnesses this principal to destroy thyroid tissue by giving the patient a radioactive form of iodine (i-131). This radioactive iodine is concentrated in the thyroid gland. The isotope primarily releases beta radiation which destroys the surrounding tissue (most of which is thyroid tissue). If there is thyroid cancer in the area, the cancer is also destroyed.
W/radioactive iodine. Nuclear medicine is used to cure thyroid cancer and hyperthyroidism (sometimes caused by graves disease). Radioactive iodine (iodine 131) is given orally in a capsule and is taken up by thyroid cells (including any cancerous cells which have spread to other parts of the body. The radioactivity kills the thyroid cells and is very effective. Usually only one dose is needed to cure hyperthyroidism.
No problem. Good example: radioactive iodine has been used since for over 60 years to cure people of thyroid cancer and graves' disease.
Thyroid disease. Most radiopharmaceuticals are used for diagnosis of functional abnormalities of organs of the body eg heart, liver, spleen, skeleton, thyroid, brain, lymph nodes, kidneys, bladder etc. Hyperthyroidism or Graves disease and thyroid cancer can be treated with high doses of I131 with destruction of thyroid tissue and curing of these problems.