Chapter 9: Problem 25
The recommended dosage of iodine- 131 is \(4.20 \mu \mathrm{Ci} / \mathrm{kg}\) of hody weight. How many microcuries of iodine- 131 are needed for a \(70.0-\mathrm{kg}\) patient with hyperthyroidism?
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Radioisotope Dosage
When dealing with radioactive dosages, it's essential to understand the measurement units. In this case, iodine-131 is measured in microcuries (μCi). One curie (Ci) is a unit of radioactivity representing the decay rate of one gram of radium-226. Microcuries are one-millionth of a curie.
Radioisotopes like iodine-131 are used because of their ability to target specific tissues. It's crucial to calculate dosages precisely to avoid excessive radiation exposure. In the example, the recommended dosage is given as 4.20 μCi/kg.
The formula for calculating the total dose is:
\[ \text{Total Dosage} = \text{Dosage per kg} \times \text{Weight of Patient} \]
This ensures a personalized dosage based on the patient's body weight, optimizing treatment efficacy and safety.
Hyperthyroidism Treatment
Iodine-131 is taken orally, usually as a capsule or liquid. Once ingested, it is absorbed by the thyroid gland. The radioactivity destroys the overactive thyroid cells, reducing hormone production. This treatment is targeted and generally well-tolerated.
Effective hyperthyroidism treatment requires precise dosing to avoid under or over-treatment. Too little iodine-131 might not adequately reduce hormone levels, while too much can damage the thyroid excessively. Calculating the correct radioactive dose is therefore vital for successful management of hyperthyroidism.
In our example, for a 70.0 kg patient, 294.0 μCi of iodine-131 was needed. Such precision helps ensure that the treatment is effective while minimizing potential side effects.
Unit Conversion
Let's review our iodine-131 dosage example. The recommended dosage was in microcuries per kilogram. Understanding what microcuries (μCi) and kilograms (kg) represent helps ensure precise calculations. One microcurie is one-millionth of a curie, and one kilogram equals 1,000 grams.
When calculating drug dosages, converting units correctly avoids errors. For example, if the recommended iodine-131 dosage was given in another unit, such as millicuries (mCi), conversion would be necessary. Here is how such conversions work:
1 curie = 1,000,000 microcuries
1 curie = 1,000 millicuries
This helps in understanding how to handle different units of measurement.
Ensuring correct dosage through proper unit conversions is essential in delivering safe and effective treatment for conditions like hyperthyroidism. This process applies to various medical and scientific calculations, highlighting the importance of mastering unit conversion skills.