Comparison of Irradiation-to-Nonirradiation Activity Ratio Between Control and Irradiation Groups
| Time after irradiation | ||||
| Group | Before irradiation | 3 mo | 6 mo | 12 mo |
| Control | 1.0 ± 0.1 | 1.0 ± 0.1 | 1.0 ± 0.9 | 1.0 ± 0.3 |
| Irradiation | 1.1 ± 0.2 | 1.2 ± 0.1 | 0.9 ± 0.3 | 0.7 ± 0.4 |
| P | 0.9 | 0.047 | 0.015 | <0.01 |