When X-rays and radioactivity were discovered towards the end of the 19th century, it did not take long before they were applied to medicine, giving birth to a brand new physics discipline: Medical Physics.
The first physicists to work in hospitals were in the radiology department, where ionising radiation was and is still used to diagnose patients. Ionising radiation is a type of particle or electromagnetic wave that carries enough energy to ionise (remove the negative part of) the atom. Apart from X-ray machines and CT (computed tomography) scanners that use ionising radiation, medical physicists oversee a wide array of equipment that is used in the hospital on a daily basis, ranging from ultrasounds to MRI (Magnetic Resonance Imaging) scanners. These complex machines provide medical images that enable radiologists to give a timely and accurate diagnosis to their patients.
In radiation oncology, medical physicists use ionising radiation to treat cancer. Apart from commissioning and performing regular quality controls of equipment, medical physicists also do a bespoke treatment plan for each and every radiotherapy patient, taking into account one’s unique anatomy. The aim of these treatment plans is to kill the cancerous cells using high-powered X-rays while sparing surrounding healthy organs as much as possible. The machines used for radiotherapy are called linear accelerators and are among the most complex machines used in modern-day hospitals.
Nuclear medicine is another branch of medical physics where radiopharmaceuticals, a group of pharmaceutical drugs bound with radioactive material, are used both for diagnosis and treatment of diseases. Medical physicists oversee the use of gamma cameras and PET (Positron Emission Tomography) scanners which are able to detect radiation emitted from these radiopharmaceuticals.
Other radioactive materials are sometimes used to treat cancer, with nuclear medical physicists calculating the optimal amount of radioactive material that should be used in order to kill a tumour while minimising radiation-induced damage to healthy tissue.
In modern hospitals, medical physicists are the glue that binds together medicine, science and technology. The continuous studies and emergence of new evidence and technologies make this field an ever-changing, fast-paced area of study where one must keep abreast with the latest evidence and research in order to remain relevant.
Although the role of a medical physicist is not well known with patients or even other healthcare professionals, it is crucial to ensure that patients receive the best healthcare possible.
Sam Agius is a nuclear medicine physicist and president of the Malta Association of Medical Physics. Mark Bezzina is radiation oncology physicist and vice-president of the association.
Sound Bites
Programming and data analysis in medical physics
• Programming and data analysis are relatively new skills in the field of medical physics. However, they are fast becoming essential tools in order to ensure that patients receive the best possible healthcare. This is why the Malta Association of Medical Physics (MAMP) actively strives to organise courses and educational sessions for its members, including those involving programming and data analysis, in order to ensure that our physicists acquire new relevant skills and keep up to date with the fast-changing world of medical physics.
https://mamp.org.mt/courses/python/
3D printing in medicine
• One of the emerging innovations in medicine is 3D printing, where a digital reconstruction can be printed into a physical 3D model. Medical physicists and other researchers are exploring ways of using this technique to develop physical objects that can be utilised for various medical applications. 3D models are being used for quality assurance, replacing expensive components that are required in quality control tests with cheaper ones. Nowadays 3D printing is also being used to print human tissue and organs in a process called bioprinting.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6036387/
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Did you know?
• In Malta there are currently 19 clinical medical physicists – 10 working at Sir Anthony Mamo Oncology Centre and nine working at Mater Dei Hospital.
• The International Day of Medical Physics is celebrated on November 7 – the day Marie Curie was born.
• Marie Curie discovered radium, a radioactive substance that was subsequently used in ‘health’ tonics.
• In 1932, one man drank 1,400 bottles of this tonic before his jaw fell off.
• People living in Ramsar, Iran receive 10 times the recommended public dose limit of radiation, but no harmful effects have been observed.
• Tobacco smoke contains a radioactive chemical element called Polonium-210, that was also used to poison the ex-Russian spy Alexander Litvinenko in London in 2006.
For more trivia see: www.um.edu.mt/think