Medical terms and common questions

This section contains a list of common terms that you may encounter in relation to clinical oncology and clinical radiology.

Clinical oncologist
A doctor trained in the diagnosis and treatment of cancer using radiotherapy and/or chemotherapy. They work closely with surgeons, clinical radiologists, pathologists and medical oncologists deciding and defining the best treatments for a patient's cancer. They plan and prescribe radiation and other therapy and liaise with psychologists, complementary therapy specialists, etc in the wider treatment of cancer and its effects. They also ensure that patients who cannot be cured are kept symptom-free.

Clinical radiologist
The modern term for a diagnostic radiologist.

Conformal radiotherapy
A treatment technique in which the beams of radiation are shaped so that the region where they overlap is as close to the same shape as ('conforms to') the organ or region requiring treatment while minimising the dose to adjacent healthy tissue.

Diagnostic radiographer
Produces and may interpret images of the body to diagnose injury and disease. Some conduct more complex investigations and ultrasonographers subspecialise in the use of ultrasound for diagnosis.

Dosimetry
The measurement of radiation dose but in the context of radiotherapy includes the characterisation of the beams of radiation from treatment machines so that the doses to be delivered to individual patients can be accurately predicted. Hence, the calculation of dose is sometimes called dosimetry.

Fractionation
The process of delivering a radiation prescription in a series of small doses spread out over many days and weeks, allowing higher doses to be delivered than is possible of all the irradiation is delivered at one time.

Intensity-modulated therapy (IMRT)
A treatment delivery technique using beams with variable intensity. An advanced form of conformal radiotherapy usually delivered by a computer-controlled linear accelerator.

Interventional radiology
This refers to a range of techniques which rely on the use of an imaging procedure (X-rays, ultrasound, CT and MRI) to guide treatment to a specific area of the body. Most interventional treatments are minimally invasive starting with passing a needle through the skin to the area requiring treatment.

Linear accelerator
The most common sort of treatment machine producing high-energy beams of X-rays. Strictly, the linear accelerator is the component of the machine in which electrons are accelerated before striking a metal target where their energy is converted to radiation. Sometimes the high-energy electron beams are used instead of the X-rays.

Medical oncologist
A doctor trained in the diagnosis and treatment of cancer who specialises in chemotherapy for selected types of cancer.

Medical physicist
A professional who specialises in physics to ensure the protection of patients, staff and the public, who checks the dose, quantity and quality of radiation produced by both diagnostic and therapy equipment and who helps plan the radiation doses used in radiotherapy.

Orthovoltage service
A radiotherapy service using low and medium energy X-rays. Orthovoltage is the term used to describe the energy of X-rays which are less penetrating that those produced by linear accelerators. Since the widespread introduction of linear accelerators (producing 'megavoltage' radiation) their use is limited to the treatment of parts of the body near to, and including, the skin surface.

Plain radiography/X-ray
A radiograph is a picture of the internal structures of the body produced by exposure to radiation (X-rays) with the image recorded on digital form, and shown on a computer screen.

Radiographer
A professional trained to operate equipment concerned with the production and detection of radiation. Radiographers work in multidisciplinary teams led by radiologists to achieve diagnosis and treatment.

Radiologists (diagnostic radiologists)
Doctors who have made a special study of radiology. They carry out the more complex investigations and are responsible for the analysing of the images. They also perform procedures under imaging guidance to obtain samples for pathology and for treating some conditions.

Radiology
The branch of medicine originating from the use of X-rays for diagnosis now called clinical radiology.

Radiotherapists
A term that is rarely used these days. Doctors trained in the delivery of radiation in the treatment of cancer. Most radiotherapists are now clinical oncologists.

Radiotherapy
The branch of medicine originating from the use of radiation, usually X-rays, to kill cancer cells now called clinical oncology.

Therapeutic radiographer
Plans and delivers prescribed treatment, using X-rays and other radio active sources. They work in close co-operation with clinical oncologists and medical physicists.

Tomography
'Tomo' is derived from the Greek word for a slice. Hence, tomography is any form of imaging where three-dimensional objects can be visualised slice by slice. X-ray computed tomography, otherwise known as CT scanning, is the most commonly used form of tomography.