Radiation doses from fluoroscopically guided cardiac catheterization procedures in children and young adults in the United Kingdom: a multicentre study.

OBJECTIVE: To gather data on radiation doses from fluoroscopically guided cardiac catheterization procedures in patients aged under 22 years at multiple centres and over a prolonged period in the UK. To evaluate and explain variation in doses. To estimate patient-specific organ doses and allow for possible future epidemiological analysis of associated cancer risks. METHODS: Patient-specific data including kerma area product and screening times from 10,257 procedures carried out on 7726 patients at 3 UK hospitals from 1994 until 2013 were collected. Organ doses were estimated from these data using a dedicated dosimetry system based on Monte Carlo computer simulations. RESULTS: Radiation doses from these procedures have fallen significantly over the past two decades. The organs receiving the highest doses per procedure were the lungs (median across whole cohort, 20.5 mSv), heart (19.7 mSv) and breasts (13.1 mSv). Median cumulative doses, taking into account multiple procedures, were 23.2, 22.2 and 16.7 mSv for these organs, respectively. Bone marrow doses were relatively low (median per procedure, 3.2 mSv; cumulative, 3.6 mSv). CONCLUSION: Most modern cardiac catheterizations in children are moderately low-dose procedures. Technological advances appear to be the single most important factor in the fall in doses. Patients undergoing heart transplants undergo the most procedures. An epidemiological assessment of cancer risks following these procedures may be possible, especially using older data when doses were higher. ADVANCES IN KNOWLEDGE: This is the first large-scale, patient-specific assessment of organ doses from these procedures in a young population.

Development of a database of organ doses for paediatric and young adult CT scans in the United Kingdom.

Despite great potential benefits, there are concerns about the possible harm from medical imaging including the risk of radiation-related cancer. There are particular concerns about computed tomography (CT) scans in children because both radiation dose and sensitivity to radiation for children are typically higher than for adults undergoing equivalent procedures. As direct empirical data on the cancer risks from CT scans are lacking, the authors are conducting a retrospective cohort study of over 240,000 children in the UK who underwent CT scans. The main objective of the study is to quantify the magnitude of the cancer risk in relation to the radiation dose from CT scans. In this paper, the methods used to estimate typical organ-specific doses delivered by CT scans to children are described. An organ dose database from Monte Carlo radiation transport-based computer simulations using a series of computational human phantoms from newborn to adults for both male and female was established. Organ doses vary with patient size and sex, examination types and CT technical settings. Therefore, information on patient age, sex and examination type from electronic radiology information systems and technical settings obtained from two national surveys in the UK were used to estimate radiation dose. Absorbed doses to the brain, thyroid, breast and red bone marrow were calculated for reference male and female individuals with the ages of newborns, 1, 5, 10, 15 and 20 y for a total of 17 different scan types in the pre- and post-2001 time periods. In general, estimated organ doses were slightly higher for females than males which might be attributed to the smaller body size of the females. The younger children received higher doses in pre-2001 period when adult CT settings were typically used for children. Paediatric-specific adjustments were assumed to be used more frequently after 2001, since then radiation doses to children have often been smaller than those to adults. The database here is the first detailed organ-specific paediatric CT scan database for the UK. As well as forming the basis for the UK study, the results and description of the methods will also serve as a key resource for paediatric CT scan studies currently underway in other countries.

Incidence and clinical features of Langerhans cell histiocytosis in the UK and Ireland.

OBJECTIVES: There are few published studies on the epidemiology of Langerhans cell histiocytosis (LCH). We undertook a survey to ascertain all newly diagnosed cases aged 0-16 years in the UK and Republic of Ireland. DESIGN: Three methods of ascertainment were used: the British Paediatric Surveillance Unit (BPSU) system, a survey by Newcastle University, and the Children's Cancer and Leukaemia Group (CCLG) registry. Deaths data were obtained from the UK Office for National Statistics and the Central Statistics Office in Ireland. Clinicians who reported cases were sent a questionnaire to obtain demographic and clinical details. RESULTS: Over the 2-year period, 94 cases were identified. The age-standardised incidence rate of LCH in children aged 0-14 years was 4.1 per million per year. The sex ratio (M:F) was 1.5:1 and the median age at diagnosis was 5.9 years. Single system disease (predominantly bony involvement) accounted for 73% of cases and 27% had multisystem disease of whom 7% had involvement of "risk organs" (liver, lung, spleen and bone marrow). Three children died, two of whom were diagnosed after death. CONCLUSIONS: This is the first study of LCH to use an active surveillance method with additional sources of ascertainment. Our incidence is comparable with those in other national reports, although it is likely to be an underestimate as each method may have missed some cases, either diagnosed or undiagnosed.

Paternal preconceptional irradiation, population mixing and solid tumors in the children of radiation workers (England).

OBJECTIVE: To investigate whether there was an increased incidence of solid tumors among offspring of male radiation workers at the Sellafield nuclear installation in Cumbria, northwest England and whether paternal preconceptional irradiation was associated with the risk of solid tumors. METHODS: A cohort study of 266,710 live births in Cumbria, 1950-1991, followed up to age 25 years on the end of 1991. RESULTS: Children of radiation workers had a non-significantly increased risk of solid tumors (RR= 1.5, 95% CI: 0.9-2.4, p = 0.09), determined largely by an increased risk of cancers excluding leukemias, lymphomas, brain, spinal and gender-specific tumors (RR= 1.9, 95% CI: 1.0-3.3, p = 0.05), which was partly explained by differing patterns of parental migration (adjusted RR= 1.7, 95% Cl: 0.8-3.2, p = 0.50). Within children of radiation workers there was no evidence of an increased risk with increasing paternal preconception dose of external radiation (hazard ratio per 100 mSv for all solid tumors=0.6, 95% CI: 0.1-1.8, p = 0.52). CONCLUSIONS: Any observed excess of solid tumors in children of radiation workers may be partly explained by population mixing. Fathers' occupational exposure to radiation before conception was not found to be risk factor for solid tumors in their children.

How complete and accurate are cancer registrations notified by the National Health Service Central Register for England and Wales?

STUDY OBJECTIVE: To assess the completeness and accuracy of notification of cancers by the National Health Service Central Register (NHSCR) for England and Wales. DESIGN: Comparison of 720 cancer registrations ascertained from NHSCR up to May 1999 with those ascertained for the same cohort from six other sources and a pathology review of the NHSCR cancer registrations. PARTICIPANTS: People born in Cumbria, north west England, 1950-89, and diagnosed with cancer throughout the UK, 1971-1989. MAIN RESULTS: Cancer diagnoses notified by NHSCR differed substantially from those determined by this pathology review for 47 of the 688 notified cases reviewed (7%; 95% CI 5%, 9%). Over one third of these discrepancies were attributable to failures in data capture or coding by the cancer registration system and almost half to changes in diagnosis; 26 of the 47 discrepant cases were reclassified as non-malignant and 21 as malignancies but with a substantially different diagnosis. The 694 confirmed malignancies represented 94% (95%CI 92%, 95%) of the 740 cancers ascertained from all sources. CONCLUSIONS: It is estimated that the cancer registration system missed at least 10% (95%CI 6%, 15%) of all incident cases of malignant disease. Without additional ascertainment from multiple sources and diagnostic review, it would be incautious to use NHSCR cancer registrations as the sole basis of an epidemiological study.

Stillbirths in relation to the coastline of Cumbria, 1950-89.

The nuclear installation at Sellafield, in west Cumbria in the north of England, has discharged radioactive waste into the Irish Sea since 1952. The objective of this paper was to investigate whether women living near to the coast in Cumbria had an increased risk of having stillborn children. A retrospective cohort analysis was carried out using all 259,050 births (4017 stillbirths) to women normally resident in Cumbria during 1950-89, allowing for year of birth, social class and birth order using (i) comparison of observed and expected numbers of stillbirths in distance bands relative to the coast, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from the coast, and (iii) logistic regression analysis of stillbirth risk in relation to distance from the coast. Comparison of observed and expected numbers of stillbirths in distance bands within 10 km of the coast did not provide evidence of an excess risk of stillbirth closer to the coast. The comparison of the cumulative observed and expected numbers of stillbirths within 10 km of the coast supported this result. Logistic regression analysis of all births in Cumbria showed that distance from the coast did not significantly influence stillbirth risk (P > 0.05). There was no evidence to suggest an increased risk of stillbirth in mothers resident nearer to the coast.

Stillbirth rates around the nuclear installation at Sellafield, North West England: 1950-1989.

BACKGROUND: The aim of the study was to investigate whether proximity to the nuclear installation at Sellafield, in Cumbria, North West of England, increases the risk of stillbirth in the resident population. The cohort consisted of all 256066 live and 4034 stillbirths to mothers usually domiciled in Cumbria, 1950-1989. METHODS: The study was a retrospective cohort analysis allowing for year of birth, social class and birth order using: (i) Poisson probability mapping, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from Sellafield, (iii) logistic regression of stillbirth risk in relation to distance and direction from Sellafield. RESULTS: Poisson probability mapping of stillbirths within 25 km of Sellafield provided no evidence to suggest that proximity to Sellafield increased the risk of stillbirth, either overall or in any specific direction. Comparison of the cumulative observed and expected numbers of stillbirths also showed no increased risk with proximity to Sellafield. Logistic regression analysis of all Cumbrian births supported these results, showing, in particular, that distance from Sellafield did not significantly influence stillbirth risk (P = 0.30). Although there was significant variation in stillbirth risk with direction (P = 0.0004), this was due to stillbirths in areas much further than 25 km from Sellafield. There was no significant effect with distance from Sellafield within any of six directional sectors (P > 0.05). CONCLUSIONS: There was no evidence to suggest that proximity to Sellafield increases the risk of stillbirth in the resident population.