Table 2.
Treatment-related characteristics
| Variable | Total (n=1,872) | CPI (−) (n=1,813) | CPI (+) (n=59) | p-value |
|---|---|---|---|---|
| Indications of radiotherapy | ||||
| Definitive | 849 (45.4) | 826 (45.6) | 23 (39.0) | < 0.001 |
| Early stage | 138 (7.4) | 135 (7.4) | 3 (5.1) | |
| Locally advanced stage | 711 (38.0) | 691 (38.1) | 20 (33.9) | |
| Preoperative | 423 (22.6) | 396 (21.8) | 27 (45.8) | |
| Postoperative | 275 (14.7) | 268 (14.8) | 7 (11.9) | |
| Salvage | 116 (6.2) | 114 (6.3) | 2 (3.4) | |
| Palliative | 209 (11.2) | 209 (11.5) | 0 | |
| Radiotherapy technique | ||||
| 3D-CRT | 1,600 (85.5) | 1,545 (85.2)a) | 55 (93.2) | 0.234 |
| IMRT | 162 (8.7) | 161 (8.9)b) | 1 (1.7) | |
| SBRT | 94 (5.0) | 91 (5.0) | 3 (5.1) | |
| 2D-RT | 16 (0.9) | 16 (0.9) | 0 | |
| Radiotherapy parameter | ||||
| Total dose (Gy) | 52.5 (44.0–60.0) | 52.5 (44.0–60.0) | 50.0 (44.0–60.0) | 0.186 |
| BED10 (Gy) | 63.5 (52.8–79.2) | 63.5 (52.8–79.2) | 60.0 (52.8–78.0) | 0.185 |
| CTV (cm3) (n=1,856)c) | 167 (88–281) | 167 (87–281) | 163 (112–256) | 0.649 |
| Reirradiation | 270 (14.4) | 258 (14.2) | 12 (20.3) | 0.189 |
| Concurrent chemoradiation | 1,252 (66.9) | 1,206 (66.5) | 46 (78.0) | 0.066 |
| History of lung cancer surgery | 849 (45.4) | 813 (44.8) | 36 (61.0) | 0.014 |
| History of radiation pneumonitis | 253 (13.5) | 237 (13.1) | 16 (27.1) | 0.002 |
| Medications | ||||
| Systemic corticosteroid user | 1,320 (70.5) | 1,274 (70.3) | 46 (78.0) | 0.202 |
| Inhaled corticosteroids user | 232 (12.4) | 211 (11.6) | 21 (35.6) | < 0.001 |
Values are presented as median (interquartile range) or number (%). BED10, biologically effective dose with an α/β ratio of 10; CPI, chronic pulmonary infection; CTV, clinical target volume; IMRT, intensity-modulated radiation therapy; SBRT, stereotactic body radiation therapy; 2D-RT, two-dimensional radiation therapy; 3D-CRT, three-dimensional conformal external beam radiation therapy.
a)
There were five patients who received 3D-CRT combined with endobronchial brachytherapy and two patients who received 3D-CRT combined with 2D-RT,
b)
There were 32 patients who received IMRT combined with 3D-CRT,
c)
CTV values could not be calculated for 16 patients who received radiotherapy based on 2D techniques.