Table 2.
The mean value and standard deviation of cumulative biological equivalent dose EQD2 (D90 and D100) and V100 at the GTV, HRCTV-pv, and IRCTV-pv of the 30 patients
| Parameter | Mean ± SD (simple size = 30; df = 29) | ||||
|---|---|---|---|---|---|
| ICBT + IMRT | CICBT | IMRT-alone | OICBT | ||
| GTV | D90 (Gy) | 103.5 ± 8.0 | 174.8 ± 52.8 | 88 ± 0.5 | 123 ± 23.3 |
| t; p value | – | t = 7.3; p = 0.00* | t = 10.5; p = 0.00* | t = 4.4; p = 0.00* | |
| D100 (Gy) | 84.7 ± 5.0 | 104.8 ± 27 | 81 ± 2.3 | 83.4 ± 4.9 | |
| t; p value | – | t = 4.4; p = 0.00* | t = 5.5; p = 0.00* | t = 0.7; p = 0.45 | |
| IRCTV-pv | D90 (Gy) | 77.7 ± 0.9 | 65.6 ± 9.1 | 78.1 ± 0.8 | 58.7 ± 4.0 |
| t; p value | – | t = 7.1; p = 0.00* | t = 1.5; p = 0.14 | t = 23.4; p = 0.00* | |
| D100 (Gy) | 63.7 ± 2.4 | 53.3 ± 3.3 | 65.1 ± 2.7 | 50.4 ± 1.8 | |
| t; p value | – | t = 14.7; p = 0.00* | t = 2.4; p = 0.02* | t = 25; p = 0.00* | |
| V100 (%) | 94.2 ± 1.9 | 74.1 ± 13.1 | 93.1 ± 2.5 | 60.5 ± 10.8 | |
| t; p value | – | t = 11.0; p = 0.00* | t = 2.6; p = 0.00* | t = 22.7; p = 0.00* | |
| HRCTV-pv | D90 (Gy) | 88.3 ± 1.8 | 105.9 ± 24.5 | 85.3 ± 0.9 | 85.5 ± 6.1 |
| t; p value | – | t = 4.0; p = 0.00* | t = 7.8; p = 0.00* | t = 2.5; p = 0.02* | |
| D100 (Gy) | 69.6 ± 6.6 | 63.9 ± 10.6 | 72.8 ± 2.0 | 62.1 ± 6.6 | |
| t; p value | – | t = 2.8; p = 0.01* | t = 1.2; p = 0.23 | t = 9.3; p = 0.00* | |
| V100 (%) | 94.4 ± 2.8 | 93.5 ± 10.3 | 92.1 ± 1.6 | 89.4 ± 8.7 | |
| t; p value | – | t = 0.6; p = 0.55 | t = 5.5; p = 0.00* | t = 4.1; p = 0.00* | |
*
Represents the level of statistical significance p < 0.05 (two tails).
ICBT – intracavitary brachytherapy, IMRT – intensity modulated radiation therapy, CICBT – 2D HDR intracavitary brachytherapy, OICBT – 3D optimized HDR intracavitary brachytherapy, GTV – gross tumor volume, IRCTV – intermediate risk clinical target volume, HRCTV – high risk clinical target volume, D100, D90 – the minimum dose to 100%, 90% of the CTV, V100 – the percent volume of the post-implant prostate receiving 100% of the prescribed dose.