Dose-responses for mortality from cerebrovascular and heart diseases in atomic bomb survivors: 1950–2003

Abstract The scientific community faces important discussions on the validity of the linear no-threshold (LNT) model for radiation-associated cardiovascular diseases at low and moderate doses. In the present study, mortalities from cerebrovascular diseases (CeVD) and heart diseases from the latest data on atomic bomb survivors were analyzed. The analysis was performed with several radio-biologically motivated linear and nonlinear dose–response models. For each detrimental health outcome one set of models was identified that all fitted the data about equally well. This set was used for multi-model inference (MMI), a statistical method of superposing different models to allow risk estimates to be based on several plausible dose–response models rather than just relying on a single model of choice. MMI provides a more accurate determination of the dose response and a more comprehensive characterization of uncertainties. It was found that for CeVD, the dose–response curve from MMI is located below the linear no-threshold model at low and medium doses (0–1.4 Gy). At higher doses MMI predicts a higher risk compared to the LNT model. A sublinear dose–response was also found for heart diseases (0–3 Gy). The analyses provide no conclusive answer to the question whether there is a radiation risk below 0.75 Gy for CeVD and 2.6 Gy for heart diseases. MMI suggests that the dose–response curves for CeVD and heart diseases in the Lifespan Study are sublinear at low and moderate doses. This has relevance for radiotherapy treatment planning and for international radiation protection practices in general.

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Radiation Dose-Response Relationships for Thyroid Nodules and Autoimmune Thyroid Diseases in Hiroshima and Nagasaki Atomic Bomb Survivors 55–58 Years After Radiation Exposure

Yearbook of Endocrinology ◽

10.1016/s0084-3741(08)70117-3 ◽

2007 ◽

Vol 2007 ◽

pp. 230-232

Author(s):

E.L. Mazzaferri

Keyword(s):

Radiation Dose ◽

Radiation Exposure ◽

Dose Response ◽

Thyroid Nodules ◽

Atomic Bomb ◽

Thyroid Diseases ◽

Autoimmune Thyroid Diseases ◽

Autoimmune Thyroid ◽

Atomic Bomb Survivors

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Radiation Risks of Uterine Cancer in Atomic Bomb Survivors: 1958–2009

JNCI Cancer Spectrum ◽

10.1093/jncics/pky081 ◽

2018 ◽

Vol 2 (4) ◽

Cited By ~ 8

Author(s):

Mai Utada ◽

Alina V Brenner ◽

Dale L Preston ◽

John B Cologne ◽

Ritsu Sakata ◽

...

Keyword(s):

Cervical Cancer ◽

Radiation Exposure ◽

Radiation Effect ◽

Atomic Bomb ◽

Uterine Cancer ◽

Radiation Risk ◽

Atomic Bomb Survivors ◽

Exposure Age ◽

Modifying Effect ◽

Effect Of Age

Abstract Background Ionizing radiation is known to be capable of causing cancer of many organs, but its relationship with uterine cancer has not been well characterized. Methods We studied incidence of uterine cancer during 1958–2009 among 62 534 female atomic bomb survivors. Using Poisson regression analysis, we fitted excess relative risk (ERR) models to uterine cancer rates adjusted for several lifestyle and reproductive factors. Person-years at risk were also adjusted for the probability of prior hysterectomy, because it could affect the subsequent risk of uterine cancer. We assessed the modifying effect of age and other factors on the radiation risk. For analysis of the modifying effect of age at radiation exposure around menarche, we compared the radiation risk for several exposure-age categories as well as using parametric models. Results There were 224 uterine corpus cancers and 982 cervical cancers. We found a significant association between radiation dose and risk of corpus cancer (ERR per Gray [ERR/Gy] = 0.73, 95% confidence interval [CI] = 0.03 to 1.87) but not for cervical cancer (ERR/Gy = 0.00, 95% CI = −0.22 to 0.31). For corpus cancer, we found statistically significant heterogeneity in ERR/Gy by age (Pheterogeneity = .001) with elevated risk for women exposed to radiation between ages 11 and 15 years (ERR/Gy = 4.10, 95% CI = 1.47 to 8.42) and no indication of a radiation effect for exposures before or after this exposure-age range. Conclusions The current data suggest that uterine corpus is especially sensitive to the carcinogenic effect of radiation exposure occurring during the mid-pubertal period preceding menarche. There is little evidence for a radiation effect on cervical cancer risk.

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Evidence for dose and dose rate effects in human and animal radiation studies

Annals of the ICRP ◽

10.1177/0146645318756235 ◽

2018 ◽

Vol 47 (3-4) ◽

pp. 97-112 ◽

Cited By ~ 6

Author(s):

M.P. Little

Keyword(s):

Dose Rate ◽

Dose Response ◽

Low Dose ◽

Atomic Bomb ◽

Dose Range ◽

Quadratic Model ◽

Linear Quadratic ◽

Dose Rates ◽

Atomic Bomb Survivors ◽

Linear Quadratic Model

For stochastic effects such as cancer, linear-quadratic models of dose are often used to extrapolate from the experience of the Japanese atomic bomb survivors to estimate risks from low doses and low dose rates. The low dose extrapolation factor (LDEF), which consists of the ratio of the low dose slope (as derived via fitting a linear-quadratic model) to the slope of the straight line fitted to a specific dose range, is used to derive the degree of overestimation (if LDEF > 1) or underestimation (if LDEF < 1) of low dose risk by linear extrapolation from effects at higher doses. Likewise, a dose rate extrapolation factor (DREF) can be defined, consisting of the ratio of the low dose slopes at high and low dose rates. This paper reviews a variety of human and animal data for cancer and non-cancer endpoints to assess evidence for curvature in the dose response (i.e. LDEF) and modifications of the dose response by dose rate (i.e. DREF). The JANUS mouse data imply that LDEF is approximately 0.2–0.8 and DREF is approximately 1.2–2.3 for many tumours following gamma exposure, with corresponding figures of approximately 0.1–0.9 and 0.0–0.2 following neutron exposure. This paper also cursorily reviews human data which allow direct estimates of low dose and low dose rate risk.

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