Table 2.
Treatment characteristics
| Characteristic | CBCT (n = 76) | Orthogonal kV (n = 48) | P |
|---|---|---|---|
|
| |||
| Treatment year | <.0001 | ||
| 2007–2009 | 1 (1) | 20 (42) | |
| 2010–2012 | 26 (34) | 25 (52) | |
| 2013–2015 | 49 (64) | 3 (6) | |
| Radiation planning | |||
| PET | 76 (100) | 48 (100) | 1 |
| 4DCT | 76 (100) | 27 (56) | <.0001 |
| Radiation delivery | |||
| Dose | |||
| Median (Gy) | 60 | 63 | .001 |
| Range (Gy) | 52–70.2 | 50.4–70.2 | |
| ≥60 Gy | 65 (86) | 41 (85) | .99 |
| GTV | |||
| Median (cm3) | 148.3 | 139.7 | .15 |
| Range (cm3) | 20.5–803.5 | 3.9–347.1 | |
| Distribution | |||
| <100 cm3 | 27 (36) | 16 (33) | |
| 100–200 cm3 | 16 (21) | 17 (35) | |
| 200–300 cm3 | 11 (14) | 10 (21) | |
| 300–400 cm3 | 8 (11) | 5 (10) | |
| ≥400 cm3 | 14 (18) | 0 (0) | |
| PTV margins (4DCT patients, n = 103) | |||
| Median (mm) | 3 | 5 | .0002 |
| Distribution | |||
| <3 mm | 6 (8) | 2 (7) | |
| 3 mm | 33 (43) | 1 (4) | |
| 4 mm | 4 (5) | 0 (0) | |
| 5 mm | 32 (42) | 21 (78) | |
| >5 mm | 1 (1) | 3 (11) | |
| Technique | .0006 | ||
| 3D-CRT only | 38 (50) | 39 (81) | |
| 3D-CRT/IMRT | 15 (20) | 7 (15) | |
| IMRT only | 23 (30) | 2 (4) | |
| MLD, median (Gy) | 19.4 | 18.5 | .18 |
| Lung V20, median (%) | 34.6 | 30.5 | .025 |
| Chemotherapy schedule | |||
| Induction | 16 (21) | 16 (33) | .13 |
| Concurrent | 76 (100) | 48 (100) | 1 |
| Adjuvant | 20 (26) | 9 (19) | .33 |
| Concurrent chemotherapy agent(s) | .30 | ||
| Carboplatin + paclitaxel | 50 (66) | 28 (58) | |
| Cisplatin + etoposide | 12 (16) | 14 (29) | |
| Other doublet | 5 (7) | 3 (6) | |
| Single agent | 9 (12) | 3 (6) | |
Abbreviations: 3D-CRT = 3-dimensional conformal radiation therapy; 4DCT = 4-dimensional computed tomography; CBCT = cone beam computed tomography; GTV = gross tumor volume; IMRT = intensity modulated radiation therapy; kV = kilovoltage; MLD = mean lung dose; PET = positron emission tomography; PTV = planning target volume; V20 = volume receiving 20 Gy.
Values are number (percentage) unless otherwise noted.