Table 3.
Dosimetric statistics for the specified OARs
| Structure | Parameter | HT | SaS-IMRT | p |
|---|---|---|---|---|
| Group 1-single tumour group | ||||
| Normal liver | Mean (Gy) | 18.24 ± 6.73(10.84-31.09) | 20.01 ± 7.86 (8.37-31.20) | n/a |
| V50%(%) | 19.17 ± 5.62(10.83-22.50) | 22.19 ± 7.13(14.17-31.25) | n/a | |
| EUD | 23.68 ± 5.14(16.60-33.97) | 29.11 ± 5.46(21.52-37.14) | < 0.05 | |
| NTCP | 1.69 ± 4.30(0.003-12.33) | 6.80 ± 9.86(0.06-29.07) | 0.051 | |
| Whole liver | V30 Gy(%) | 36.41 ± 14.88(16.45-62.00) | 39.44 ± 16.57(16.94-62.06) | n/a |
| Lt kidney | Mean (Gy) | 2.48 ± 2.43 (0.30-6.44) | 2.83 ± 3.61(0.17-9.00) | n/a |
| Rt kidney | Mean (Gy) | 4.13 ± 3.09 (0.42-8.03) | 5.55 ± 4.55(0.15-10.57) | n/a |
| GIS | Max (Gy) | 30.18 ± 18.17(8.65-52.56) | 32.67 ± 17.27(11.77-53.45) | n/a |
| Spinal cord | Max (Gy) | 15.30 ± 9.14(5.12-34.28) | 22.05 ± 11.10(4.58-34.78) | n/a |
| Group 2-multiple tumours group | ||||
| Normal liver | Mean (Gy) | 25.89 ± 3.43(18.89-28.45) | 29.73 ± 6.71 (15.54-36.96) | < 0.05 |
| V50%(%) | 36.46 ± 4.92(29.17-41.67) | 51.74 ± 11.46(37.5-69.17) | < 0.05 | |
| EUD | 28.09 ± 3.23(21.95-31.87) | 34.68 ± 3.80(27.77-38.43) | < 0.05 | |
| NTCP | 2.38 ± 2.25(0.07-6.15) | 20.27 ± 13.29(1.23-38.33) | < 0.05 | |
| Whole liver | V30 Gy(%) | 43.91 ± 10.43(23.12-53.42) | 55.00 ± 14.28(27.11-74.97) | < 0.05 |
| Lt kidney | Mean (Gy) | 4.18 ± 2.94 (0.66-9.21) | 2.60 ± 2.03(0.37-6.97) | n/a |
| Rt kidney | Mean (Gy) | 6.11 ± 4.16 (0.99-12.38) | 6.45 ± 4.76(0.93-14.58) | n/a |
| GIS | Max (Gy) | 39.59 ± 12.42(21.42-53.20) | 42.05 ± 12.36(19.67-52.78) | n/a |
| Spinal cord | Max (Gy) | 18.08 ± 5.38(10.58-28.19) | 23.66 ± 8.65(8.96-32.20) | < 0.05 |
Abbreviation: SaS-IMRT: Step-and-shoot intensity-modulated radiotherapy;; HT: helical tomotherapy; EUD: Equivalent uniform dose; NTCP: Normal tissue complication probability; GIS: Gastrointestinal system (including stomach and small bowels); Lt: left side; Rt: right side; n/a: not statistical significance; statistical significance (p < 0.05) is reported between couples from the paired Wilcoxon signed-rank test analysis.