Table II.
Population size, breast cancer cases, woman-years, and radiation dose by cohort.
| Cohort | Country | Women a | Exposed breasts b | Cases a | Woman-years a | Mean dose (Gy)c (range) | Type of exposure |
|---|---|---|---|---|---|---|---|
| Life Span Study | Japan | 47726 | 38010 | 707 | 1182306 | 0.3 (0.02 - 5) | Atomic bomb radiation; gamma rays with a small neutron component; single high-dose-rate exposure |
| Massachusetts Original | US | 1494 | 1608 | 103 | 44616 | 1.0 (0.02 - 6) | Repeated chest fluoroscopies (X-rays); many low-dose fractions at high dose rates |
| Massachusetts Extension | US | 3068 | 2576 | 108 | 45410 | 0.7 (0.02 - 5) | Repeated chest fluoroscopies (X-rays); many low-dose fractions at high dose rates |
| New York Mastitis | US | 1811 | 767 | 114 | 35585 | 3.8 (0.6 - 14) | 175-250 kVp therapeutic X-rays; small number of high-dose-rate fractions |
| Rochester Thymus | US | 3312 | 2008 | 34 | 59222 | 0.7 (0.02 – 7.5) | 80-250 kVp therapeutic X-rays; small number of high-dose-rate fractions |
| Benign Breast Disease | Sweden | 3034 | 1778 | 210 | 63417 | 5.8 (0.02 - 50) | 170-175 kVp therapeutic X-rays; small number of high-dose-rate fractions |
| Gothenburg Hemangioma | Sweden | 7469 | 11115 | 71 | 169635 | 0.17 (0.02 – 22) | External gamma radiation from Ra226 applicators; mainly protracted low-dose- rate exposures |
| Stockholm Hemangioma | Sweden | 9613 | 12059 | 155 | 246242 | 0.52 (0.02 – 35) | External gamma radiation from Ra226 applicators; mainly protracted low-dose- rate exposures |
| Total | 77527 | 69921 | 1502 | 1846433 | |||
a
Total for exposed and unexposed women in the cohort.
b
Total number of breasts exposed to at least 0.02 Gy.
c
Values are for breasts that received a total dose in the range 0.02 to 10 Gy.
Adapted from Preston et al. 2002b, with permission.