TY - JOUR T1 - Negotiating the risks of computed tomography in primary care JF - British Journal of General Practice JO - Br J Gen Pract SP - 86 LP - 87 DO - 10.3399/bjgp20X708029 VL - 70 IS - 691 AU - Julie-Ann Moreland AU - Fergus V Gleeson AU - Brian D Nicholson Y1 - 2020/02/01 UR - http://bjgp.org/content/70/691/86.abstract N2 - Computed tomography (CT) is one of the most frequently used imaging modalities. Over 5 million scans were performed in the UK in 2017/2018, a 6.9% increase from 2016/2017. One in ten scans performed for initial cancer investigations were referred directly from GPs.1 Versatility of scanners, an ageing population, patient knowledge, and improved access are some factors that have led to an increase in demand; however, there is regional variation in direct-access radiology for GPs in the UK.1 When GPs have direct access to cancer investigations, they diagnose cancer in a similar proportion of patients to specialists with the same test.2 The risks of ionising radiation from CT conflict with the demand for earlier cancer diagnosis creating a risk/benefit dilemma. GPs who frequently refer to CT may come under pressure from commissioners for their use of radiology, but if slow to refer they may be criticised for late diagnoses following repeat patient attendances.3This piece aims to improve understanding of the risks of ionising radiation and who is responsible for them.Effects of ionising radiation are divided into deterministic and stochastic. Deterministic effects are the cause-and-effect relationship between the amount of radiation absorbed and the likelihood of an event occurring. A minimum dose must be absorbed before a deterministic event can occur, for example, skin erythema can occur from 2 Gy. Stochastic effects occur by chance with any exposure to radiation, potentially increasing the chances of a carcinogenic event. Public Health England (PHE) estimates that the average UK adult is exposed to 2.7 mSv of background radiation a year. The average … ER -