Specialisms | Medical Physics

It’s tough to know where to start when describing medical physics – it’s a wide-ranging subject that covers everything from health and safety to diagnostic imaging, physiological measurement, and even cancer treatment. The broad scope means that it’s difficult to concisely describe the role of a medical physicist, but I’ll do my best!

Physicists often operate “behind the scenes” in hospitals, working on optimising techniques, ensuring the safety of staff and patients and guaranteeing quality in treatments. These roles can take many forms, such as the testing of diagnostic imaging and treatment units, calculations of radiation shielding requirements and patient radiation doses and the development of new techniques for use in a clinical setting. While the STP doesn’t involve much independent research, the MSc project is a good place to get an experience of what research and development is like in the field of medical physics.

The STP for medical physics is split into four different sub-specialisms, namely Radiation Safety Physics, Imaging with Ionising Radiation, Imaging with Non-Ionising Radiation and Radiotherapy Physics. The first year of the STP is spent rotating through these areas, before specialising in one of them. Radiation safety is focused on radiation shielding and radiation protection and crosses over with every other specialism, giving it a much broader scope than other specialisms.

While selecting a medical physics specialism is sometimes up to the trainee, many placement centres specify a specialism in the application process. Also, some of those that don’t will still have an idea of where they want their trainees to specialise – so bear this in mind when applying! I’ve known trainees in larger centres where there was only one place in each specialism with four trainees all wanting the same one. If you know which specialism you’d like when applying, it might be best to apply for a place that is specifically for that field.

My specialism is radiotherapy, and this is where most medical physics trainees specialise. Radiotherapy is the use of radiation to treat cancer and physics tasks are broadly separated into two roles: dosimetry and treatment planning.

Dosimetry tasks are those that ensure treatment is as accurate as possible and includes tasks such as quality assurance (QA) of the linear accelerator (linac) treatment units. Other dosimetry includes calibration of ionisation chambers which are used to measure linac radiation output during QA. This, therefore, is the “hands-on” area of radiotherapy,

Treatment planning in radiotherapy is the process of determining the treatment fields that will provide the optimal coverage of the patient’s tumour whilst sparing the surrounding healthy tissue. Most treatments are planned using computer software which can calculate accurately radiation dose deposited throughout a volume (though some involve more mathematical aspects). Planning can be an interesting challenge as a sort of mathematical and visual puzzle, and is certainly my favourite area, especially when a difficult plan can provide a good challenge.

The STP offers an excellent opportunity to enter a field that many people are unaware of. While many aspects of the STP are challenging, it’s well worth applying if you think that medical physics is a career you might enjoy.