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Table 3 Differences between Nominal Index and Simple IMRT plans

From: Comparison of simple and complex liver intensity modulated radiotherapy

Structure Index IMRT Mean [Range] Simple IMRT Mean [Range] p-value
Segment Number* 47 [34-52] 18 [6-30] <0.001
Complexity Score 0.51 [0.2-0.72] 0.63 [0.35-0.85] <0.001
RTOG CI 1.42 [0.99-2.02] 1.52 [1.11-2.21] 0.001
Monitor Units 1892 [953-3761] 1695 [934-3832] 0.012
PTV D95 (Gy) 42.4 [28.1-60.7] 42.4 [28.1-60.8] 0.197
PTV D99 (Gy) 41.0 [27.3-58.7] 40.6 [27.2-58.7] <0.001
PTV Min. 0.5 mL (Gy) 40.0 [25.7-59.4] 39.5 [25.7-59.5] 0.006
PTV EUD (-20) (Gy) 44.5 [29.4-63.9] 44.6 [29.6-64.6] 0.066
Liver NTCP (%) 2.7 [0-5] 2.4 [0-5] 0.370
Effective Liver Volume 0.38 [0.07-0.7] 0.38 [0.07-0.71] 0.418
Mean Liver Dose (Gy) 15.1 [2.4-20.2] 15.1 [2.7-19.8] 0.809
Mean Kidney Dose (Gy) 3.3 [0-13.7] 3.4 [0.3-11.7] 0.509
Max. Cord Dose (Gy) 16.4 [2.6-24] 16.2 [2.3-24.8] 0.713
Max.Stomach Dose (Gy) 19.6 [1.1-30] 19.4 [0.6-30] 0.548
Max. Duodenum Dose (Gy) 10.1 [0-29.9] 9.9 [0-29.4] 0.648
Max. Bowel Dose (Gy) 9.9 [0-30] 9.7 [0-30] 0.545
Max. Esophagus Dose (Gy) 16.1 [0-30] 16.1 [0-29.6] 0.980
Max. Heart Dose (Gy) 24.5 [0-43.9] 25.3 0.048
Max. Ribs Dose (Gy) 37.7 [0-48] 38.2 [0-48] 0.044
Integral Dose (J) 68.7 [4.7-181.6] 69.1 [5.2-173.9] 0.374
  1. * primary endpoint for analysis
  2. Max. is maximum dose to 0.5 mL of relevant structure except for cord where the point maximum dose is reported.