Table 5.
Comparison of targets in T1-2 NPC patients.
| Median (IQR) | P-value | |||||||
|---|---|---|---|---|---|---|---|---|
| Target | Index | IMRT | VMAT | TOMO | P | I vs. V | I vs. T | V vs. T |
| PGTVnx | V69.96 (%) | 95.00 (95.00-96.00) | 97.00 (96.00-98.00) | 97.42 (96.22-98.05) | <0.001 | 0.004 | <0.001 | 1 |
| D2 (Gy) | 74.54 (74.00-75.45) | 73.71 (73.16-74.43) | 75.13 (74.55-75.75) | 0.076 | _ | _ | _ | |
| D50 (Gy) | 72.24 (71.99-72.95) | 71.85 (71.61-72.29) | 73.28 (72.28-73.56) | 0.002 | 0.045 | 0.991 | 0.002 | |
| D95 (Gy) | 69.97 (69.81-70.15) | 70.35 (70.03-70.47) | 70.47 (70.16-70.66) | <0.001 | 0.006 | 0.001 | 1 | |
| D98 (Gy) | 69.11 (68.27-69.34) | 69.68 (69.36-69.89) | 69.79 (69.29-69.97) | <0.001 | 0.011 | <0.001 | 0.991 | |
| CI | 0.330 (0.270-0.420) | 0.370 (0.240-0.430) | 0.325 (0.274-0.473) | 0.128 | _ | _ | _ | |
| HI | 0.080 (0.070-0.100) | 0.060 (0.050-0.080) | 0.078 (0.062-0.086) | 0.032 | 0.028 | 0.875 | 0.37 | |
| PCTV-1 | V59.4 (%) | 99.00 (98.00-99.00) | 99.00 (98.00-100.00) | 99.21 (97.93-99.80) | 0.22 | _ | _ | _ |
| D2 (Gy) | 74.18 (73.45-75.10) | 73.51 (72.89-74.03) | 74.88 (74.42-75.41) | 0.003 | 0.017 | 1 | 0.006 | |
| D50 (Gy) | 70.52 (69.97-70.96) | 70.69 (70.24-71.09) | 70.53 (69.90-71.00) | 0.532 | _ | _ | _ | |
| D95 (Gy) | 62.62 (61.49-64.29) | 63.41 (62.03-64.07) | 61.71 (60.55-62.27) | 0.014 | 0.433 | 0.433 | 0.011 | |
| D98 (Gy) | 60.63 (59.90-61.96) | 61.52 (60.68-62.29) | 60.29 (59.30-61.41) | 0.076 | _ | _ | _ | |
| CI | 0.250 (0.230-0.300) | 0.270 (0.240-0.350) | 0.330 (0.210-0.360) | 0.002 | 0.036 | 0.003 | 1 | |
| PCTV-2 | V54 (%) | 98.00 (97.00-98.00) | 98.00 (97.00-99.00) | 97.83 (96.53-98.82) | 0.336 | _ | _ | _ |
| D2 (Gy) | 73.46 (72.83-74.41) | 73.12 (72.63-73.54) | 74.32 (73.77-75.15) | 0.05 | _ | _ | _ | |
| D50 (Gy) | 62.57 (61.39-64.19) | 62.49 (60.61-64.26) | 60.90 (58.39-63.15) | 0.004 | 0.768 | 0.004 | 0.105 | |
| D95 (Gy) | 55.19 (55.01-55.49) | 55.10 (54.63-55.40) | 55.10 (54.68-55.86) | 0.692 | _ | _ | _ | |
| D98 (Gy) | 53.75 (53.45-54.25) | 54.05 (53.24-54.54) | 54.08 (52.86-54.60) | 0.504 | _ | _ | _ | |
| CI | 0.700 (0.680-0.750) | 0.760 (0.750-0.810) | 0.730 (0.670-0.780) | <0.001 | <0.001 | 0.875 | 0.004 | |
IMRT/I, intensity modulated radiation therapy; VMAT/V, volumetric modulated arc therapy; TOMO/T, tomotherapy; Gy, gray; IQR, inter-quartile range; DV, the absorbed dose in v% of the volume; CI, conformity index; HI, homogeneity index; Vx, the volume of organ receiving more or equal to x Gy.