Table 5.
Incidence Rates of CHD events by Estimated Cardiac Radiation Dose from Hempelmann’s Thymic Irradiation Cohort
| Dose (Gy) | Number of Persons | Person Years at Risk | Mean Dose Gy (Std Dev) |
Median Dose (Gy) | MI Cases | MI Rate (per 10,000 p-yrs) |
Rate Ratio of CHD Compared to Non-irradiated (95%CI)a |
Fully Adjusted Rate Ratio of CHD (95%CI)b |
|---|---|---|---|---|---|---|---|---|
| Non-Irradiated | 4833 | 213,024 | – | – | 206 | 9.67 | Ref | Ref |
| Total Irradiated | 2657 | 126,244 | 1.45 (1.28) | 1.40 | 144 | 11.41 | 1.12 (0.90–1.39) | 1.07 (0.86–1.32) |
| 0.01–0.99 | 1058 | 45,659 | 0.55 (0.21) | 0.25 | 22 | 4.82 | 0.81 (0.51–1.24) | 1.14 (0.70–1.75) |
| 1.00–1.99 | 923 | 43,533 | 1.59 (0.15) | 1.56 | 51 | 11.72 | 1.28 (0.93–1.73) | 1.26 (0.91–1.70) |
| 2.00–2.99 | 323 | 17,735 | 2.45 (0.10) | 2.46 | 33 | 18.61 | 1.17 (0.79–1.66) | 0.96 (0.65–1.37) |
| 3.00–20.99 | 229 | 12,486 | 4.28 (0.58) | 4.00 | 29 | 23.23 | 1.31 (0.87–1.89) | 1.10 (0.47–1.61) |
| Irradiated but dose unknown | 124 | 6831 | – | – | 9 | 13.18 | 0.82 (0.39–1.51) | 0.65 (0.31–1.20) |
|
Test of trendc P = 0.07 |
Test of trendd P > 0.50 |
Analysis was performed with the AMFIT module of Epicure on all 7490 subjects in the thymus irradiation group
a Rate ratio is based on dose category model adjusted by attained age and sex
b Fully adjusted rate ratio is based on a dose category model adjusted for attained age and sex, diabetes, dyslipidemia, ever smoked, and hypertension
c Test for trend of rate ratios by dose categories. Excludes subjects in the unknown radiation dose category
d Test for trend of rate ratios by dose categories adjusted for attained age, sex, diabetes, dyslipidemia, ever smoking, hypertension