Table 1.
Patient characteristics.
|
Patients with no TLN, N = 221 (%a) |
Patients with TLN, N = 13 (%a) |
P
Valueb |
|
| Age, median (range), years | 59 (14-88) | 54 (23-71) | .128 |
| Sex | 1.000 | ||
| Male | 55.20 | 53.80 | |
| Female | 44.80 | 46.20 | |
| Primary sites | <.001 | ||
| Major salivary glands | 35.30 | 0 | |
| Sinonasal | 31.20 | 23.10 | |
| Nasopharynx | 13.10 | 23.10 | |
| Ears and skin | 10.00 | 15.40 | |
| Other minor salivary glandsc | 1.80 | 0 | |
| Oral cavity | 4.10 | 38.50 | |
| Others | 4.50 | 0 | |
| Histology | .010 | ||
| SCC | 32.60 | 46.20 | |
| ACC | 19.90 | 53.80 | |
| Sarcoma | 5.00 | 0 | |
| Esthesioneuroblastoma | 2.30 | 0 | |
| Others | 40.30 | 0 | |
| T stage | .153 | ||
| T1-T2 | 42.50 | 23.10 | |
| T3-T4 | 50.20 | 76.90 | |
| Txd | 7.20 | 0 | |
| N stage | .414 | ||
| N0-N1 | 74.70 | 76.90 | |
| N2-N3 | 15.40 | 23.10 | |
| Nx | 10.00 | ||
| Comorbidities | |||
| Hypertension | 34.80 | 38.50 | .773 |
| Diabetes | 9.50 | 23.10 | .136 |
| Smoking | .780 | ||
| Yes | 43.90 | 38.50 | |
| No | 56.10 | 61.50 | |
| Concurrent chemotherapy | .252 | ||
| Yes | 43.00 | 61.50 | |
| No | 57.00 | 38.50 | |
| Type of radiation | .694 | ||
| Proton only | 86.40 | 84.60 | |
| IMRT + proton boost | 13.60 | 15.40 | |
| Proton technique | .773 | ||
| US | 65.20 | 61.50 | |
| PBS | 34.80 | 38.50 | |
| Radiation dose, median (range) | |||
| Proton only, GyRBE | 66 (45-77) | 70 (66-76) | .001 |
| Proton boost, GyRBE | 20 (10-48.8) | 26 | .145 |
| IMRT + proton boost, GyRBE | 70 (60-76) | 76 | .104 |
| Median dose per fraction, GyRBE | 2 (1.8-2.12) | 2 (2.0-2.12) | .518 |
| Temporal lobe dose-volume parameters, median (IQR)e | |||
| aV40 | 1.9 (0-8.7) | 20.0 (11.3-31.6) | <.001 |
| aV50 | 0.6 (0-5.0) | 16.3 (8.4-24.3) | <.001 |
| aV60 | 0 (0-1.3) | 7.3 (4.8-17.4) | <.001 |
| aV70 | 0 (0) | 1.8 (0.5-11.2) | <.001 |
| Dmean | 7.3 (0.4-16.7) | 24.5 (12.6-33.9) | <.001 |
| Dmax | 54.9 (15.8-68.6) | 76.0 (70.6-80.8) | <.001 |
| D0.5cm3 | 50.9 (8.3-63.2) | 74.9 (71.1-79.7) | <.001 |
| D1cm3 | 46.3 (5.6-61.0) | 74.0 (70.3-79.2) | <.001 |
| D2cm3 | 33.5 (1.8-55.9) | 70.0 (65.0-78.1) | <.001 |
Abbreviations: TLN, temporal lobe necrosis; SCC, squamous cell carcinoma; ACC, adenoid cystic carcinoma; IMRT, intensity-modulated radiation therapy; US, uniform scanning; PBS, pencil-beam scanning; IQR, interquartile range; aV40, aV50, aV60, and aV70, absolute volume of the temporal lobe receiving 40, 50, 60, 70 GyRBE, respectively, in cm3; D0.5cm3, D1cm3, and D2cm3, dose to the 0.5 cm3, 1 cm3, and 2 cm3 volume, respectively, receiving the maximum dose in GyRBE; Dmean, mean dose in GyRBE; Dmax, maximum dose in GyRBE.
Percentages are rounded to 1 decimal place.
P value <.05 was considered statistically significant.
Other minor salivary glands included primary sites of lacrimal duct, orbit, and parapharyngeal space.
Tx consisted of unknown primary cancers, schwannoma, paraganglioma and chordoma.
Left and right temporal lobes were considered separately.