Table 1. Patient, tumor and treatment characteristics.
| Characteristic | Non-shrinking field group (N = 47) | Shrinking field group (N = 50) | P value | |
|---|---|---|---|---|
| Gender | ||||
| Male | 44 (94) | 47 (94) | > 0.99 | |
| Female | 3 (6) | 3 (6) | ||
| Age (yr), median (range) | 57 (40–69) | 57 (33-76) | 0.25 | |
| Smoking history (pack-years) | ||||
| ≥ 30 | 36 (77) | 45 (90) | 0.19 | |
| < 30 | 11 (23) | 5 (12) | ||
| Histopathology | ||||
| Squamous | 32 (68) | 40 (80) | 0.39 | |
| Adenocarcinoma | 8 (17) | 6 (12) | ||
| No specific type | 7 (15) | 4 (8) | ||
| Upper lobe vs. other location | ||||
| Upper | 32 (68) | 32 (64) | 0.67 | |
| other | 15 (32) | 18 (36) | ||
| Location type | ||||
| Central type | 31 (66) | 35 (70) | 0.67 | |
| Peripheral type | 16 (34) | 15 (30) | ||
| Volume of GTV (cm3), mean, (95% CI) | 102.9 (76.4–129.3) |
116.8 (91.8-141.8) |
0.44 | |
| Volume of PTV (cm3), mean, (95% CI) | 458.0 (405.6–510.5) | 493.0 (447.4–538.6) |
0.31 | |
| Clinical stage | ||||
| IIIA | 22 (47) | 20 (40) | 0.50 | |
| IIIB | 25 (53) | 30 (60) | ||
| Median decreases in PTV (cm3), (range) | 184.2 (28.1– 449.7) | |||
| Dose to PTV (Gy), median (range) | 60 (46-69) | 60 (46–70) | 0.17 | |
| ≥ 60 Gy | 29 (62) | 35 (70) | 0.39 | |
| < 60 Gy | 18 (38) | 15 (30) | ||
| Chemotherapy | ||||
| Platinum + taxane | 30 (64) | 37 (74) | 0.36 | |
| Platinum +pemetrexed | 5 (11) | 6 (12) | ||
| Other regimens | 12 (26) | 7 (14) | ||
| Chemotherapy cycles | ||||
| ≥ 4 | 39 (83) | 37 (74) | 0.28 | |
| < 4 | 8 (17) | 13 (26) | ||
| Concurrent chemoradiotherapy | ||||
| Yes | 28 (60) | 35 (70) | 0.58 | |
| No | 19 (40) | 15 (30) | ||
| Technology | ||||
| IMRT | 38 (81) | 43 (86) | 0.49 | |
| 3D-CRT | 9 (19) | 7 (14) | ||
| Dosimetric data | ||||
| V5 (%), mean, (95% CI) | 48.3 (45.2–51.3) | 49.7 (46.2–53.2) | 0.54 | |
| V20 (%), mean, (95% CI) | 26.5 (25.0–28.0) | 26.9 (25.0–28.8) | 0.77 | |
GTV - gross tumor volume; CI - confidence interval; PTV - planned target volume. IMRT - intensity-modulated radiation therapy; 3D-CRT - three-dimensional conformal treatment; Vdose - the percentage of lung volume irradiated to doses exceeding a threshold. Platin including carboplatin, cisplatin or nedaplatin.