Table 1.
Distribution of patient, tumor, and treatment factors for entire cohort (N = 480).
| Characteristic | Parameter | IMRT (N = 334) | PBT (N = 146) | P value |
|---|---|---|---|---|
| Age (years) | Mean, Median (Minimum-Maximum) | 59.0, 60 (26 – 82) | 61.3, 64 (26 – 76) | 0.018 |
| PTV (cc) | Mean, Median (Minimum-Maximum) | 707, 653 (112 – 2554) | 552, 506 (174 – 1727) | <0.001 |
| Gender, n (%) | Female | 40 (12) | 15 (10) | 0.59 |
| Male | 294 (88) | 131 (90) | ||
| Stage, n (%) | I | 1 (0) | 4 (3) | 0.09 |
| IIA | 115 (34) | 46 (32) | ||
| IIB | 10 (3) | 8 (5) | ||
| III | 196 (59) | 82 (56) | ||
| IVA | 12 (4) | 6 (4) | ||
| KPS, n (%) | 70 | 13 (4) | 2 (1) | 0.25 |
| 80–100 | 321 (96) | 144 (99) | ||
| Tumor location, n (%) | Upper-Middle | 19 (6) | 6 (4) | 0.47 |
| Lower | 315 (94) | 140 (96) | ||
| Induction chemotherapy, n (%) | No | 205 (61) | 96 (66) | 0.36 |
| Yes | 129 (39) | 50 (34) | ||
| Histology, n (%) | Adenocarcinoma | 313 (94) | 140 (96) | 0.14 |
| SCC | 21 (6) | 5 (3) | ||
| Other | 0 | 1 (1) |
Abbreviations: IMRT = intensity-modulated radiation therapy, PBT = proton beam therapy, PTV = planning target volume, KPS = Karnofsky performance status, SCC = Squamous cell carcinoma, RT = radiation therapy.