| Factor | Patients’ characteristics |
| Sex | All female |
| Age | Median 58 years (range, 44 - 75 years) |
| Relapse | Yes: 14 patients No: 9 patients |
| Interval between the final irradiation dose and RIOP diagnosis | Median 4 months (range, 1 - 10.5 months) |
| Pathology | IDC: 21 lesions DCIS: 4 lesions |
| TNM | TisN0M0: 4 lesions T1N0M0: 21 lesions |
| Radiation dose | 50 Gy/25 fractions: 9 patients 60 Gy/30 fractions: 10 patients 42.56 Gy/16 fractions: 1 patient 53.2 Gy/20 fractions: 1 patient Right 50 Gy/25 fractions and left 60 Gy/30 fractions: 2 patients |
| Boost | Yes: 12 patients No: 9 patients |
| White blood cell count | Median 7000/ml (range, 4000 - 14,900/ml) |
| CRP | 2.2 mg/dl (range, 0.05 - 15.48 mg/dl) Normal (less than 0.30 mg/dl): 5 Borderline (0.36 mg/dl): 1 High (more than 0.70 mg/dl): 12 |
| Hormone therapy | Yes: 18 patients No: 5 patients |
| Chemotherapy | Yes: 4 patients No: 19 patients |
| RIOP ratio in the whole lung | Median 7.4% (range, 0.7% - 17.7%) |
| Corticosteroids | Yes: 17 patients (use methylprednisolone: 6 patients) No: 6 patients |
| Prednisolone per unit body weight | 0.40 mg/kg (range, 0.21 - 1.2 mg/kg) |
| Prednisolone dose reduction rate | Median 0.25 mg/day (range, 0 - 0.85 mg/day) |