Brief Article
Copyright ©2012 Baishideng Publishing Group Co.
World J Clin Oncol. Apr 10, 2012; 3(4): 57-62
Published online Apr 10, 2012. doi: 10.5306/wjco.v3.i4.57
Table 1 Critical structure dose tolerances
Critical structure/organ at riskDose (Gy)
Ant tongue (1/2 or 1/3)70
Brainstem54
Brain - 50%54
Brachial plexus60
Spinal cord45
Cochlea30
Parotid – 50%30
Table 2 Patient characteristics
PtPathology/site/stageHDIDEDPlan
1SCCOropharynxT3N37056VMAT
2SCCLarynxT4N0706356VMAT
3SCCOropharynxT2N2A7060VMAT
4SCCLarynxT3N2B6666VMAT
5SCCLarynxT3N2C7056VMAT
6SCCOropharynxT2N2B7056VMAT
7SCCOropharynxT3N07056VMAT
8SCCLarynxT4N2C7056VMAT
9SCCNasopharynxT1N3706055VMAT
10SCCOropharynxT1N16656VMAT
11SCCLarynxT3N07056VMAT
12MedullaryThyroidT4bN1b6666VMAT
13SCCOropharynxT4N2C7063VMAT
14SCCOropharynxT2N2C7056VMAT
15SCCHypopharynxT2N37056VMAT
16SCCOropharynxT2N37060VMAT
17SCCLarynxT3N07056IMRT
18SCCOropharynxT3N2C7056IMRT
19SCCOropharynxT3N2B7056VMAT
20SCCOropharynxT2N17056VMAT
Table 3 Target volume dose delivery analysis of volumetric intensity-modulated arc therapy (two arcs) and intensity modulated radiation therapy (seven to ten sliding window fields) plans
Monitor unitsConformity indexDose Homogeneity
PatientVMATIMRTVMATIMRTVMATIMRT
143122111.151.192.472.59
253012642.691.851.231.78
346518531.741.971.312.34
458416811.341.351.612.33
552614231.691.381.151.95
659315602.001.431.072.01
755220461.791.661.082.34
852215791.341.282.062.66
967214731.721.700.982.46
1066813591.901.422.381.91
1161410003.071.671.050.79
1253320471.271.381.921.42
1348320871.861.581.412.05
1453113191.651.231.272.06
1554411882.411.671.581.27
1652017692.502.431.691.06
1751911143.272.391.111.19
1854212731.631.641.310.81
1956512582.161.841.441.01
2046311353.952.260.980.58
Mean542.851612.582.001.611.451.73
P value< 0.0010.0030.069
Table 4 Mean dose to organs at risk across all intensity modulated radiation therapy and volumetric intensity-modulated arc therapy plans
Mean dose (Gy)P value
IMRTVMAT
Ant tongue52.751.10.135
Brainstem15.314.30.264
Left cochlea23.718.80.002
Right cochlea22.419.3< 0.001
Left parotid46.846.50.68
Right parotid47.346.70.373
Spinal cord20.420.90.173