Table 3.
Comparison of OAR dose between the scheduled and adapted plans
| OAR | Number | Scheduled plan (cGy) | Adapted plan (cGy) | Difference over a treatment course* (Gy) | Mean % difference | Minimum relative difference (%) | Maximum relative difference (%) | P value |
| Oral cavity mean | 36 | 60.4 | 58.5 | –0.67 | –3.2 | –34.21 | 73.91 | .39 |
| Superior constrictor mean | 11 | 87 | 86.7 | –0.11 | –0.31 | –57.89 | 24.78 | .94 |
| Middle constrictor mean | 22 | 94.9 | 93.3 | –0.56 | –1.7 | –37.87 | 37.04 | .6 |
| Inferior constrictor mean | 21 | 60.5 | 60.5 | 0 | –0.03 | –17.58 | 19.84 | .99 |
| Parotid ipsilateral mean | 28 | 74.9 | 65.5 | –3.29 | –12.53 | –43.53 | 40.54 | .013 |
| Parotid contralateral mean | 36 | 46.8 | 48.9 | 0.74 | 4.57 | –25 | 75.38 | .08 |
| SMG contralateral mean | 25 | 79.3 | 74.7 | –1.61 | –5.83 | –60.27 | 29.11 | .16 |
| Larynx mean | 26 | 86.3 | 77.5 | –3.08 | –10.17 | –28.32 | 18.57 | <.01 |
| Esophagus mean | 35 | 59 | 57.6 | –0.49 | –2.3 | –17.39 | 54.24 | .38 |
| Spinal cord Dmax | 38 | 111.3 | 101.7 | –3.36 | –8.63 | –28.68 | 24.62 | <.01 |
| Mandible Dmax | 36 | 202.6 | 200.8 | –0.63 | –0.88 | –6.88 | 15.66 | .09 |
| Brain stem Dmax | 19 | 101.8 | 94.5 | –2.56 | –7.24 | –26.15 | 17.78 | .035 |
Abbreviations: Dmax = maximum dose; OAR = organ at risk; SMG = submandibular gland.
⁎
Theoretical benefit if the difference between the scheduled and adapted plan is multiplied over a definitive course of 35 fractions. Hypothetical analysis performed for easier understanding of the dose-per-fraction difference between the 2 plans.
Values in boldface are statistically significant.