Table 1.
Patient characteristics
| Characteristic | IMRT No. (%) | IMPT No. (%) | P Value |
|---|---|---|---|
| Age, years | 0.093 | ||
|
| |||
| ≤ 60 | 301 (56.4) | 22 (44.0) | |
| >60 | 233 (43.6) | 28 (56.0) | |
|
| |||
| Sex | 0.621 | ||
|
| |||
| Female | 72 (13.5) | 8 (16.0) | |
| Male | 462 (86.5) | 42 (84.0) | |
|
| |||
| Race | 0.272 | ||
|
| |||
| White | 476 (89.1) | 42 (84.0) | |
| Other | 58 (10.9) | 8 (16.0) | |
|
| |||
| Disease site | 0.365 | ||
|
| |||
| Base of tongue | 260 (48.7) | 21 (42.0) | |
| Tonsil/other | 274 (51.3) | 29 (58.0) | |
|
| |||
| Tumor location | 0.256 | ||
|
| |||
| Left | 238 (44.6) | 26 (52.0) | |
| Right | 288 (53.9) | 22 (44.0) | |
| Midline | 2 (0.4) | 1 (2.0) | |
| Bilateral | 6 (1.1) | 1 (2.0) | |
|
| |||
| T category | 0.032 | ||
|
| |||
| T1-2 | 347 (65.0) | 40 (80.0) | |
| T3-4 | 187 (35.0) | 10 (20.0) | |
|
| |||
| N category | 0.622 | ||
|
| |||
| N0-1 | 92 (17.2) | 10 (20.0) | |
| N2-3 | 442 (82.8) | 40 (80.0) | |
|
| |||
| HPV status | 0.635 | ||
|
| |||
| Positive | 364 (68.2) | 35 (70.0) | |
| Negative | 75 (14.0) | 4 (8.0) | |
| Equivocal | 18 (3.4) | 2 (4.0) | |
| Not detected | 77 (14.4) | 9 (18.0) | |
|
| |||
| Induction CT | 0.930 | ||
|
| |||
| Yes | 217 (40.6) | 20 (40.0) | |
| No | 317 (59.4) | 30 (60.0) | |
|
| |||
| Concurrent CT | 0.623 | ||
|
| |||
| Yes | 360 (67.4) | 32 (64.0) | |
| No | 174 (32.6) | 18 (36.0) | |
Abbreviations: IMRT, intensity-modulated (photon) radiotherapy; IMPT, intensity-modulated proton therapy; HPV, human papillomavirus; CT, chemotherapy.