Unsealed Source Radiotherapy

Unsealed Source Radiotherapy

Unsealed source radiotherapy involves the use of radioactive substances in soluble forms that are introduced into the body through injection or ingestion. These substances are chosen for their biological properties, which mimic those of their non-radioactive counterparts.

Contrastingly, sealed-source therapy, known as brachytherapy, entails the use of radioisotopes contained within capsules or metal wires during treatment, preventing them from dissolving into bodily fluids.

For instance, iodine, a substance absorbed by the thyroid gland in healthy individuals, can be utilized to treat thyroid disorders, including benign conditions like thyrotoxicosis and malignant conditions like papillary thyroid cancer.

Radioactive iodine, such as iodine-131, is concentrated in the thyroid, emitting beta and gamma radiation. The beta radiation eradicates thyroid tissue and any thyroid cancer cells that absorb the iodine, while most of the gamma radiation exits the patient's body.

After treatment with radioactive iodine, the patient's urine and their own body emit radiation. The radioactive iodine not absorbed by the thyroid is expelled through the kidneys into the urine. Depending on the dosage administered, it may take several days to weeks for the radioactivity to decrease to a level where the patient no longer poses a radiation hazard to others. Strict radiation protection regulations govern the use of such radioactive sources to ensure safety.