The glossary explains some of the words used across this website and covers some key cancer and research terms, which primarily focus on lung cancer.


Healthcare professional who operates medical imaging equipment – such as X-rays or computed tomography scanners – used to detect, diagnose or treat a disease.1 See also ‘Low-dose computed tomography’ and ‘Radiologist’


Medical doctor specialising in diagnosing and treating injuries and diseases using medical imaging techniques, such as X-ray, computed tomography and ultrasound.2 See also ‘Chest X-ray’, ‘Computed tomography’, ‘Low-dose computed tomography’ and ‘Radiographer’

Randomised controlled trial (RCT)

A type of clinical trial that randomly assigns participants into two or more groups that share similar characteristics. RCTs measure outcomes at specific times and carry out statistical analysis on any differences observed between the groups. They are used to assess whether a new intervention (the experimental group) is more effective than a similar intervention (comparison group) or usual care (control group). As RCTs follow a set protocol designed to minimise the potential for bias, they are considered the ‘gold standard’ in clinical evidence.3 See also ‘Cohort study’

Rapid referral pathway

A rapid referral pathway (also known as an urgent referral pathway) is an intervention that aims to minimise the time between the detection, diagnosis and treatment of lung cancer by reducing the number of steps in the care pathway for lung cancer.4 See also ‘Care pathway’


When a cancer comes back after a period when it could not be detected. Recurrent cancer can grow in the original site (e.g. in the lung) or elsewhere in the body; a new type of cancer developing in the same person is not a recurrence.5


A decrease in or disappearance of signs and symptoms of cancer. Remission can be partial (i.e. some but not all signs of cancer have disappeared) or complete (i.e. all signs and symptoms of cancer have gone, but the disease may still be in the body).5 See also ‘Symptoms’

Resectable tumour

A resectable tumour (also known as an operable tumour) is one which can be removed with surgery.5 See also ‘Surgical resection’

Retrospective study

A study that analyses data that have been recorded in the past. For example, data collected from cancer registries over several years may be later analysed to understand the impact of an intervention such as lung cancer screening.6 Retrospective studies do not follow up with participants.7 See also ‘Cancer registry’, ‘Cohort study’ and ‘Prospective study’

Risk factor

Conditions that may increase an individual’s susceptibility to a disease. Risk factors for lung cancer include lifestyle (e.g. smoking history, physical activity),8 personal (e.g. age, other respiratory diseases, family history of lung cancer) and environment factors (e.g. air pollution, passive smoking, occupational exposure to carcinogens such as asbestos).9 See also ‘Asbestos’, ‘Carcinogens’ and ‘Risk prediction model’

Risk prediction model

A statistical model also known as a risk calculator that combines different risk factors (e.g. age, sex, family history of cancer) to estimate the probability of an individual developing lung cancer. It produces a risk score which may be used to determine if an individual is eligible for lung cancer screening.10 See also ‘Risk factor’


  1. WebMD. What is a radiographer? [Updated 28/06/21].  Available from: [Accessed 12/04/22]

  2. American College of Radiologists. What Is a Radiologist?  Available from: [Accessed 30/03/22]

  3. Aberle DR, Adams AM, Berg CD, et al. 2011. Reduced lung-cancer mortality with low-dose computed tomographic screening. New England Journal of Medicine 365(5): 395-409

  4. Pollock M, Craig R, Chojecki D, et al. 2018. Initiatives to accelerate the diagnostic phase of cancer care: an environmental scan. Edmonton, Canada: Institute of Health Economics

  5. National Cancer Institute. NCI Dictionary of Cancer Terms.  Available from: [Accessed 04/03/22]

  6. Learning Hub. Prospective vs retrospective studies.  Available from: [Accessed 07/03/22]

  7. Ranganathan P, Aggarwal R. 2018. Study designs: Part 1 – An overview and classification. Perspect Clin Res 9(4): 184-86

  8. International Agency for Research on Cancer. 2020. World cancer report: Cancer research for cancer prevention. Lyon: IARC

  9. Corrales L, Rosell R, Cardona AF, et al. 2020. Lung cancer in never smokers: The role of different risk factors other than tobacco smoking. Crit Rev Oncol Hematol 148: 102895

  10. Toumazis I, Bastani M, Han SS, et al. 2020. Risk-based lung cancer screening: A systematic review. Lung cancer (Amsterdam, Netherlands) 147: 154-86