Physics in healthcare

When thinking about a career or what to study in university, many students interested in science think that they have to decide between a more academic route or something more vocational, such as medicine. Whilst both paths are highly rewarding, it is possible to mix the two. An example of this is nuclear medicine, allowing physics students to become healthcare professionals.

Nuclear medicine is an area of healthcare that involves introducing a radioactive isotope into the system of a patient in order to image their body. A radioactive isotope is an unstable nucleus that decays and emits radiation. This radiation can then be detected, usually by a tool known as a gamma camera. It sounds dangerous, however it is a fantastic tool that allows us to identify abnormalities, view organs in motion and even prevent further spreading of tumours.

So, how does the patient receive the isotope? It depends on the scan they are having! The most common route is injection but it is also possible for the patient to inhale or swallow the isotope. Some hospitals give radioactive scrambled eggs or porridge to the patient in gastric emptying imaging.

The radioisotope needs to obey some conditions:

● It must have a reasonable half-life. The half-life is the time it takes for the isotope to decay to half of the original activity. If the half-life is too short, the scan will be useless as nothing will be seen. If it is too long, the patient will be radioactive and spread radiation into their immediate surroundings for a long period of time.

● The isotope must be non-toxic. It cannot harm the patient!

● It must be able to biologically attach to the area of the body that is being investigated. If we want to look at bones, there is no point in giving the patient an isotope that goes straight to the stomach.

● It must have radiation of suitable energy. The radiation must be picked up by the cameras and they will be designed to be most efficient over a specific energy range. For gamma cameras, this is around 100-200 keV. Physicists are absolutely essential in nuclear medicine. They have to understand the properties of radiation, run daily quality checks to ensure the scanners are working, they must calibrate devices so that the correct activity of radiation is being given to patients and so much more. It is essential that the safety of patients and healthcare professionals is the first priority when it comes to radiation. With the right people on the job, safety and understanding is the priority of daily tasks. Nuclear medicine is indeed effective and is implemented into standard medicine thanks to the work of physicists.

Written by Megan Martin