Radioactive decay - waves and particles Study Guide

Nuclear radiations, primarily gamma rays, are used in medicine for both diagnostic and therapeutic purposes. For exploring internal organs, doctors use tracers that emit radiation. These tracers are typically radioactive isotopes with short half-lives, meaning they decay quickly and expose the patient to minimal radiation. They are absorbed by specific organs or tissues. A detector, like a gamma camera, can then be used externally to create an image of the radiation distribution, revealing the structure and function of the organ. For example, technetium-99m is commonly used as a medical tracer because it emits gamma rays, has a relatively short half-life of 6 hours, and can be easily incorporated into many different pharmaceutical compounds. For the control or destruction of unwanted tissue, such as cancerous cells, higher doses of radiation are used. This process is known as radiotherapy. High-energy radiation, including gamma rays from sources like Cobalt-60 or X-rays, is directed precisely at the cancerous cells. The radiation damages the DNA within these cells, preventing them from growing and dividing, eventually leading to their death. Careful targeting is crucial to minimise damage to healthy surrounding tissues. The choice of radiation type and dose depends on the specific medical application and the location of the target tissue. Both applications require careful management of radiation exposure to ensure patient safety while achieving the desired medical outcome.