It is an applied branch of physics. It deals with application of physics concepts and methods for diagnosis and treatment of diseases. It is a discipline that is concerned with introducing new and more precise techniques into health related investigation and treatment of individual patient. Specifically, for past several decades, ionizing radiation is being used worldwide for the treatment of cancer and diagnosis of the various diseases. In treatment, the goal is to deliver the maximum radiation dose to the tumour and minimum radiation dose to the surrounding healthy tissues for obtaining better treatment outcome. In diagnosis the aim is to obtain better image quality with minimum radiation dose. Medical physics is the branch of science that mainly deals with the applications of ionizing radiation in health care through radiotherapy, diagnostic radiology, nuclear medicine and the associated radiological protection.
|Areas of medicine||Specific topics benefited from concepts of physics|
|General Medicine||Instrumentation, radioactive isotopes for dilution analysis, metabolic investigation, radioimmunoassay etc.|
|Anaesthetics||Application of the physics of gases and aerosols in studies connected with respiratory systems|
|Cardiology||Electrocardiography, echocardiography, ballistocardiograph, muscle simulation, blood pressure and flow investigations.|
|Dermatology||Treatment of skin diseases by radiation and skin colour measurements|
|Neurology and Neurosurgery||Magnetic Resonance Imaging (MRI), Ultrasound, electrical and electronic techniques to study nerve transmission network. Brain tumour detection by radiation.|
|Obsterics, Gynaecology and Oncology||Radioisotope tracer investigations, Ultrasound techniques to monitor fetal developments, tumour detection, radiation treatment of cancer.|
|Opthalmology and Otology||Diagnosis and treatment of defects in vision, assessment and treatment of deafness and noise control.|
|Pathology, Physical Medicine, Radiology and Radiotherapy||Microscopy, short wave and microwave treatment, electrical simulators, telemetry, imaging of internal organs, mineral content of bones, radiotherapy of cancer|
|Surgery||Laser applications, Lithotripsy, Tumour localisation by CT, MRI techniques, Bio-medical devices|
GLOBOCAN data of International Agency for Research on Cancer, a World Health Organization entity, estimates that globally, 1 in 5 people develop cancer during their lifetime, and 1 in 8 men and 1 in 11 women die from the disease. Almost 60% of them require radiotherapy treatment.
Figure 1: Estimated number of cancer cases from 2020 to 2040 (Source: GLOBOCAN, WHO)
Figure 1 shows the estimates for 2040, predicting that countries classified with "Low or Medium Human Development Index (HDI) "will have the greatest relative increases in cancer incidence by 2040.
This increase in number of cancer cases and dependency on radio therapy treatments, requires increase in related equipment. Figure 2(a) from International Atomic Energy Agency, Directory of Radiotherapy Centers, shows that distribution of radiotherapy machines per million population.
Figure 2: (a) Number of Radiotherapy Machines per Million People (Source: DIRAC, IAEA). (b) Number of equipment per regions. (Source: DIRAC, IAEA)
Southeast Asia a lagging way behind and is in the second position from the bottom. Specifically for India it is less than 1 per million. The maximum number of cancer patients that can be treated annually is around 500 per Teletherapy equipment. Therefore, using present ~660 teletherapy equipment available in India, the maximum number of patients that can be treated annually is about 333000, which is far below the required number of equipment to cater the total rising no. of cancer patients in India (~1.3 million as per the GLOBOCAN factsheet). Thus, there is a need for tripling the number of existing teletherapy equipment which in-turn requires large number of medical physicists. The demand for equipment will soon grow and more centers must be setup.The information on the age distribution of the equipment and equipment categories in India is shown in Figure 3(a) and 3(b) respectively.
Figure 3: (a) Radiotherapy equipment type in India (Source: DIRAC, IAEA). (b) Radiotherapy equipment age distribution in India. (Source: DIRAC, IAEA)
Further, the required number of medical physicists will increase considering complexity as it will require more man-hours for performing quality assurance (QA) of the equipment & patient specific QA, treatment planning etc. in advanced technologies.
The total number of registered medical physicists in India is about 1042. This includes 361 women – which is just 35% of the total. With the demand for number of equipment tripling, the number of the medical physicists also will increase by three times. Now about 100 medical physicists are getting trained per annum. Assuming there is no further increase in cancer cases and hence no further requirement of equipment, it will take 10 years to meet the gap. Hence there is a need for more medical physicists to be trained.
There are around 24 institutions in the country that are capable of training medical physicists with around 14 institutions (>60%) concentrated in South India. Such a course is being conducted for the first time in Odisha.