Table 3. Dosimetric comparison of salivary glands between conventional and optimized IMRT plans.
| Structure | Conventional (N=15) | Optimized (N=15) | t | P value |
|---|---|---|---|---|
| Submandibular gland | ||||
| Dmean (Gy) | 32.36±2.74 | 28.82±2.70 | 12.69 | <0.001 |
| V39 (%) | 28.14±9.77 | 16.29±7.76 | 10.95 | <0.001 |
| Parotid gland | ||||
| Dmean (Gy) | 29.07±2.17 | 23.85±1.70 | 18.35 | <0.001 |
| V26 (%) | 45.41±4.82 | 33.82±4.30 | 11.32 | <0.001 |
Data are presented as mean ± standard deviation. Conventional plan: CTV1 60 Gy; GTVnd 66 Gy; optimized plan: CTV2 50.4 Gy; GTVnd 60 Gy. CTV1 comprised regions surrounding the primary tumor and high-risk nodal drainage areas, and CTV2 included low-risk nodal drainage areas. CTV, clinical target volume; GTVnd, nodal gross tumor volume; IMRT, intensity-modulated radiotherapy.