Table 3.
Doses to the OARs of the VMAT plans with three different MSWs for 19 cervical cancer patients
| OAR | Parameter | 0.5 cm MSW | 1.0 cm MSW | 1.5 cm MSW | p 1 | p 2 | p 3 |
|---|---|---|---|---|---|---|---|
| Spinal cord | Dmax (Gy) | 25.18 ± 3.89 | 24.28 ± 3.79 | 23.13 ± 3.59 | 0.08 | 0.01a | 0.02 |
| Rectum | V30 Gy (%) | 8.96 ± 2.25 | 8.43 ± 2.19 | 9.01 ± 2.20 | 0.15 | 0.55 | 0.06 |
| Bladder | V30 Gy (%) | 12.49 ± 3.16 | 11.73 ± 2.79 | 12.21 ± 2.97 | 0.12 | 0.83 | 0.15 |
| Kidney‐L | V45 Gy (%) | 62.10 ± 5.40 | 63.53 ± 5.44 | 61.51 ± 5.58 | 0.28 | 0.92 | 0.16 |
| Kidney‐R | V45 Gy (%) | 48.38 ± 4.10 | 47.62 ± 4.04 | 48.52 ± 4.24 | 0.42 | 0.74 | 0.66 |
| Femoral head‐L | V30 Gy (%) | 38.91 ± 2.63 | 39.32 ± 2.75 | 41.68 ± 3.56 | 0.75 | 0.14 | 0.07 |
| Femoral head‐R | V30 Gy (%) | 37.56 ± 3.73 | 40.77 ± 3.91 | 39.87 ± 3.98 | 0.06 | 0.36 | 0.67 |
p 1, p‐value comparing 0.5 and 1.0 cm MSW plans; p 2, p‐value comparing 0.5 and 1.5 cm MSW plans; p 3, p‐value comparing 1.0 and 1.5 cm MSW plans. VMAT, volumetric modulated arc therapy; OAR, organ‐at‐risk; MSW, minimum segment width; Dmax, maximum dose; Vx, percentage volume of region of interest receiving at least X Gy.
a
statistically significant according to Bonferroni correction.