Table 4.
Incidence Rates of MI 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 MI Compared to Non-irradiated (95%CI)a |
Fully Adjusted Rate Ratio of MI (95%CI)b |
|---|---|---|---|---|---|---|---|---|
| Non-Irradiated | 4833 | 213,411 | – | – | 130 | 6.09 | Ref | Ref |
| Total Irradiated | 2657 | 126,513 | 1.45 (1.28) | 1.40 | 83 | 6.56 | 1.02 (0.77–1.34) | 0.98 (0.74–1.30) |
| 0.01–0.99 | 1058 | 45,694 | 0.55 (0.21) | 0.25 | 17 | 3.72 | 1.00 (0.58–1.62) | 1.34 (0.77–2.20) |
| 1.00–1.99 | 923 | 43,610 | 1.59 (0.15) | 1.56 | 33 | 7.57 | 1.31 (0.88–1.90) | 1.14 (0.76–1.65) |
| 2.00–2.99 | 323 | 17,791 | 2.45 (0.10) | 2.46 | 20 | 11.24 | 1.12 (0.68–1.74) | 0.83 (0.49–1.33) |
| 3.00–20.99 | 229 | 12,568 | 4.28 (0.58) | 4.00 | 8 | 6.37 | 0.56 (0.56–1.06) | 0.74 (0.33–1.42) |
| Irradiated but dose unknown | 124 | 6850 | – | – | 5 | 7.30 | 0.73 (0.26–1.61) | 0.63 (0.22–1.39) |
|
Test of trendc P = 0.10 |
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