Table 1.
Patients’ characteristics
| No | % | |
|---|---|---|
| Sex | ||
| Male | 81 | 43.3 |
| Female | 106 | 56.7 |
| Location | ||
| Parotid | 29 | 15.5 |
| Submandibular | 37 | 19.8 |
| Sublingual | 16 | 8.6 |
| Minor salivary gland | 105 | 56.1 |
| Histologic grade | ||
| 1 | 76 | 40.6 |
| 2 | 77 | 41.2 |
| 3 | 20 | 10.7 |
| Unknown | 14 | 7.5 |
| Tumor size (cm) | ||
| Median 2.5 (0.4–9.0) | ||
| T stage | ||
| T1 | 52 | 0.5 |
| T2 | 62 | 27.8 |
| T3 | 32 | 33.2 |
| T4 | 40 | 17.1 |
| Tx | 1 | 21.4 |
| N stage | ||
| N0 | 173 | 92.5 |
| N1 | 6 | 3.2 |
| N2 | 8 | 4.3 |
| Extracapsular extension | ||
| No | 176 | 94.1 |
| Yes | 11 | 5.9 |
| Lymph node dissection | ||
| Not performed | 131 | 70.1 |
| Performed | 56 | 29.9 |
| Surgical margin | ||
| Positive | 104 | 55.6 |
| Close | 57 | 30.5 |
| Negative | 26 | 13.9 |
| PNI | ||
| No | 95 | 50.8 |
| Yes | 92 | 49.2 |
| LVI | ||
| No | 156 | 83.4 |
| Yes | 31 | 16.6 |
| Nerve invasion | ||
| No | 173 | 92.5 |
| Yes | 14 | 7.5 |
| Bone invasion | ||
| No | 146 | 78.0 |
| Yes | 41 | 21.9 |
| Treatment type | ||
| Surgery only | 61 | 32.6 |
| Surgery + postop RT | 106 | 56.7 |
| Surgery + postop CCRT | 16 | 8.6 |
| Preop CTx + surgery + postop RT | 2 | 1.1 |
| Preop CCRT + surgery | 1 | 0.5 |
| Preop RT + surgery | 1 | 0.5 |
| RT technique | ||
| 3D CRT | 22 | 17.5 |
| IMRT | 100 | 79.4 |
| Unknown | 4 | 3.2 |
| RT field | ||
| Tumor bed | 47 | 37.3 |
| Tumor bed + elective LN area | 75 | 59.5 |
| Unknown | 4 | 3.2 |
| RT dose (total, Gy) | ||
| Median 63.0 (36.0–70.4) | ||
| Neck treatment | ||
| Not performed | 83 | 44.4 |
| Performed | 104 | 55.6 |
| Aim of neck treatment | ||
| Therapeutic | 14 | 13.5 |
| Elective | 90 | 86.5 |
| Type of neck treatment | ||
| Elective neck dissection | 29 | 27.9 |
| Elective neck irradiation | 47 | 45.2 |
| Elective neck dissection + irradiation | 14 | 13.5 |
| Therapeutic neck irradiation | 1 | 0.9 |
| Therapeutic neck dissection + irradiation | 13 | 12.5 |
PNI perineural invasion, LVI lymphovascular invasion, RT radiotherapy, CCRT concurrent chemoradiotherapy, CTx chemotherapy, 3D CRT 3-dimensional conformal radiotherapy, IMRT intensity-modulated radiotherapy, LN lymph node