Table 2.
Characteristics of patients who received three courses of irradiation with carbon‐ion radiotherapy for locoregionally recurrent, metastatic, or secondary lung tumors
| Characteristic | Patients (n = 8) |
|---|---|
| cStage at initial irradiation, n (%) | |
| Primary lung cancer | 4 (50.0) |
| Metastatic lung cancer | 4 (50.0) |
| Re‐irradiation field, n (%) | |
| Central | 3 (37.5) |
| Peripheral | 5 (62.5) |
| Interval between re‐irradiation and the third irradiation, months; median (range) | 22 (9‐55) |
| Follow‐up after re‐irradiation, months; median (range) | 16 (1‐89) |
| Third irradiation dose, Gy (RBE); median | 72.0 |
| Site of failure at re‐irradiation, n (%) | |
| In‐field (initial irradiation and re‐irradiation) | 6 (75.0) |
| In‐field (initial irradiation) and marginal zone (re‐irradiation) | 1 (12.5) |
| In‐field (re‐irradiation) and marginal zone (third course of irradiation) | 1 (12.5) |
| CTV for the third irradiation, mL; median (range) | 65.0 (36.5‐91.3) |
cStage, clinical stage; CTV, clinical target volume; RBE, relative biological effectiveness.