Table 1.
Baseline patient and treatment characteristics
| Characteristic | Number (% or IQR) |
| Median age (years) | 64 (59-72) |
| Male | 29 (52.7%) |
| Prior surgery | 34 (61.8%) |
| Histology | |
| Squamous cell carcinoma | 52 (94.5%) |
| Thyroid carcinoma | 2 (3.6%) |
| Adenocarcinoma | 1 (1.8%) |
| Concurrent cetuximab | 45 (81.8%) |
| Median prior EBRT dose (Gy) | 68.6 (64.3-70.0) |
| Median re-irradiation interval (months) | 21.5 (9.0-62.3) |
| Number of SBRT courses | |
| 1 | 50 (90.9%) |
| 2 | 3 (5.4%) |
| 3 | 2 (3.6%) |
| Site of recurrence | |
| Oropharynx | 14 (25.5%) |
| Neck | 14 (25.5%) |
| Larynx | 12 (21.8%) |
| Oral cavity | 10 (18.2%) |
| Base of skull | 3 (5.5%) |
| Nasopharynx | 2 (3.6%) |
| Median SBRT dose (Gy) | 44.0 (44.0-44.0) |
| Median SBRT PTV (cc) | 35.0 (16.8-59.7) |
IQR = interquartile range. EBRT = external beam radiation therapy. SBRT = stereotactic radiation therapy. PTV = planning target volume.