Table 1 Mean percent volumes of organs at risk receiving 30, 25, 20, or 5 Gy and mean dose to organs at risk via anteroposterior-posteroanterior (AP-PA) or butterfly intensity-modulated radiation therapy (IMRT) techniques
Organ at risk | IMRT | AP-PA | Difference | P value* | |
|---|---|---|---|---|---|
Right breast | V30 | 0.5% | 1.9% | −1.4% | 0.01 |
V25 | 1.9% | 3.1% | −1.2% | 0.03 | |
V20 | 3.8% | 3.7% | 0.1% | 0.44 | |
V5 | 13.7% | 7.5% | 6.2% | 0.01 | |
Mean Dose, Gy | 2.28 | 1.92 | 0.36 | 0.26 | |
Left breast | V30 | 1.2% | 2.9% | −1.7% | 0.02 |
V25 | 2.8% | 4.2% | −1.4% | 0.01 | |
V20 | 4.0% | 4.9% | −0.9% | 0.01 | |
V5 | 11.2% | 8.4% | 2.8% | 0.01 | |
Mean Dose, Gy | 2.42 | 2.38 | 0.04 | 0.41 | |
Right ventricle | V30 | 12.3% | 28.7% | −16.4% | 0.01 |
V25 | 21.7% | 33.4% | −11.7% | 0.01 | |
V20 | 27.4% | 35.8% | −8.4% | 0.01 | |
V5 | 41.2% | 42.7% | −1.5% | 0.17 | |
Mean Dose, Gy | 10.25 | 12.16 | −1.91 | 0.09 | |
Left ventricle | V30 | 7.3% | 9.7% | −2.4% | 0.28 |
V25 | 2.6% | 15.8% | −13.2% | 0.01 | |
V20 | 4.6% | 18.8% | −14.2% | 0.01 | |
V5 | 21.5% | 29.7% | −8.2% | 0.21 | |
Mean Dose, Gy | 4.13 | 7.72 | −3.59 | 0.02 | |
Left anterior descending artery | V30 | 21.5% | 28.5% | −7.0% | 0.28 |
V25 | 26.4% | 38.2% | −11.8% | 0.01 | |
V20 | 28% | 42.2% | −14.2% | 0.01 | |
V5 | 51.8% | 51.7% | 0.1% | 0.55 | |
Mean Dose, Gy | 10.44 | 14.46 | −4.02 | 0.02 | |
Heart | V30 | 16.8% | 29% | −12.2% | 0.01 |
V25 | 23.8% | 35.7% | −11.9% | 0.01 | |
V20 | 28.3% | 38.8% | −10.5% | 0.01 | |
V5 | 42.5% | 46.0% | −3.5% | 0.34 | |
Mean Dose, Gy | 11.52 | 14.26 | −2.74 | 0.01 | |
Total lung | V30 | 4.8% | 19.5% | −14.6% | 0.01 |
V25 | 15.4% | 26.5% | −11.1% | 0.01 | |
V20 | 22.2% | 29.9% | −7.7% | 0.01 | |
V5 | 54.0% | 41.1% | 12.9% | 0.17 | |
Mean Dose, Gy | 9.25 | 11.31 | −2.06 | 0.01 | |
Spinal cord | V30 | 5.6% | 57.8% | −52.2% | 0.01 |
V25 | 35.3% | 61.7% | −25.4% | 0.01 | |
V20 | 50.4% | 63.8% | −13.4% | 0.01 | |
V5 | 75.6% | 75.7% | −0.1% | 0.86 | |
Mean Dose, Gy | 17.16 | 21.93 | −4.77 | 0.01 |