Definition

Noun: 1. A radioactive isotope of iodine: Iodine-125 is a specific, artificially produced form of the element iodine. Its atomic nucleus is unstable and decays over time, emitting radiation. It is characterized by a half-life of 60 days, meaning half of its radioactivity decays in that period. 2. A medical diagnostic and therapeutic agent: Due to its radioactive properties and specific uptake by the thyroid gland, iodine-125 is used in medicine. It serves as a radioactive tracer to study thyroid function and as a localized radiation source to treat an overactive thyroid (hyperthyroidism).

Usage Examples

• As a radioactive isotope:
  • The laboratory ordered a shipment of iodine-125 for their research.
  • The half-life of iodine-125 makes it suitable for certain medical procedures.
• As a medical agent:
  • The patient received iodine-125 as a tracer for a thyroid uptake scan.
  • Treatment with iodine-125 seeds is one option for certain cancers.

Advanced Usage

• "I-125": This is a common abbreviated form used in scientific and medical contexts.
  • The implant contained I-125 seeds.
• "Iodine-125 seed": Refers specifically to a small, sealed radioactive source containing I-125, used in a cancer treatment called brachytherapy.
  • Prostate brachytherapy often involves the permanent implantation of iodine-125 seeds.

Variants and Related Words

• Radioiodine (n): A general term for any radioactive isotope of iodine, which includes iodine-125 as well as iodine-131.
• Tracer (n): A radioactive substance, like iodine-125, introduced into the body to study organ function.
• Radiopharmaceutical (n): A medicinal product containing a radioisotope, such as iodine-125, used for diagnosis or therapy.

Synonyms

• I-125 (n): The standard abbreviation.
• Radioactive iodine (specific isotope) (n): While "radioactive iodine" is a broader term, in specific medical contexts it can refer to iodine-125.

Related Phrases and Terms

• Thyroid uptake study: A diagnostic test that often uses iodine-125 as the tracer.
• Brachytherapy: A form of radiation therapy where a radioactive source, such as an iodine-125 seed, is placed inside or next to the area requiring treatment.
• Half-life: A key property of iodine-125, describing the time it takes for half of its radioactive atoms to decay.

Noun

1. light radioactive isotope of iodine with a half-life of 60 days; used as a tracer in thyroid studies and as a treatment for hyperthyroidism