| |
The first 15 fractions
|
Between fraction 15 and 25
|
|---|
| |
SCT-1 vs. SCT-2
|
SCT-2 vs. SCT-3
|
|---|
|
Volume changes
|
Mean ± SD
|
95% CI
|
p
Value
|
Mean ± SD
|
95% CI
|
p
Value
|
|---|
|
GTVnx
|
8.23 ± 13.61
|
4.24; 12.24
|
0.000
|
3.30 ± 8.09
|
0.92; 5.67
|
0.008
|
|
GTVnd
|
10.27 ± 13.37
|
6.02; 14.51
|
0.000
|
4.88 ± 8.41
|
2.19; 7.57
|
0.001
|
|
L-PG
|
2.06 ± 2.99
|
1.19; 2.94
|
0.000
|
5.90 ± 2.99
|
5.02; 6.78
|
0.000
|
|
R-PG
|
2.46 ± 4.50
|
1.14; 3.78
|
0.000
|
4.68 ± 3.23
|
3.74; 5.63
|
0.000
|
|
CON-PG
|
2.98 ± 3.50
|
1.80; 4.17
|
0.000
|
5.78 ± 3.00
|
4.77; 6.80
|
0.000
|
|
IP-PG
|
1.81 ± 3.94
|
0.78; 2.85
|
0.001
|
4.99 ± 3.23
|
4.14; 5.84
|
0.000
|
|
Dose changes
|
Plan 1 vs. Plan 2
|
Plan 3 vs. Plan 4
|
|
(PG V30)
|
Mean ± SD
|
95% CI
|
p
Value
|
Mean ± SD
|
95% CI
|
p
Value
|
|
L-PG
|
−6.87 ± 15.58
|
−11.45; −2.29
|
0.004
|
−0.81 ± 15.94
|
−5.49; 3.87
|
0.728
|
|
R-PG
|
−5.61 ± 16.04
|
−10.32; −0.90
|
0.021
|
−1.14 ± 21.54
|
−7.46; 5.19
|
0.719
|
|
CON-PG
|
−3.41 ± 13.44
|
−8.18; 1.36
|
0.155
|
0.25 ± 21.61
|
−7.42; 7.91
|
0.948
|
|
IP-PG
|
−7.77 ± 16.76
|
−12.06; −3.48
|
0.001
|
−1.64 ± 17.33
|
−6.07; 2.80
|
0.464
|
-
Abbreviations: SD standard deviation, CI confindence interval, R-PG the right parotid gland, L-PG the left parotid gland, GTVnx the gross tumor volume of the nasopharynx, GTVnd the cervical lymph node, Con-PG contralateral parotid gland, IP-PG ipsilateral parotid gland, V30 the percentage of parotid gland volume receiving ≥ 30Gy, SCT-1 the first simulation CT scan before treatment, SCT-2 the second simulation CT scan at the fifteenth fraction of treatment, SCT-3 the third simulation CT scan at the twenty-fifth fraction of treatment, Plan 1 the initial IMRT plan generated based on the SCT-1, Plan 2 was made by applying the beam configurations of Plan 1 to SCT-2, Plan 3 the re-IMRT plan on the SCT-2, Plan 4 was made by applying the beam configurations of Plan 3 to SCT-3.
