Table 3.
Biological equivalent dose (BED) and equivalent dose in 2 Gy per fraction (EQD2) for various SRS/HSRT radiation schedules
| Dose regimen | BED Gy10 (Tumor) | EQD10/2 | BED Gy2 (Brain Parenchyma) | EQD2/2 |
|---|---|---|---|---|
| 30 Gy/5 fractions | 48 | 40 | 120 | 60 |
| 25 Gy/5 fractions | 37.5 | 31.25 | 87.5 | 43.75 |
| 27 Gy/3 fractions | 51.3 | 42.75 | 148.5 | 74.25 |
| 24 Gy/3 fractions | 43.2 | 36 | 120 | 60 |
| 20 Gy/1 fraction | 60 | 50 | 220 | 110 |
| 18 Gy/1 fraction | 50.4 | 42 | 180 | 90 |
| 16 Gy/1 fraction | 41.6 | 34.67 | 144 | 72 |
| 14 Gy/1 fraction | 33.6 | 28 | 112 | 56 |
| 12 Gy/ 1 fraction | 26.4 | 22 | 84 | 42 |
BED Gy10, biological equivalent dose with an α/β ratio of 10 Gy; BED Gy2, biological equivalent dose with an α/β ratio of 2 Gy; EQD10/2, eqivalent dose in 2 Gy/fractions with a BED Gy10; EQD2/2, eqivalent dose in 2 Gy/fractions with a BED Gy2; SRS, stereotactic radiosurgery; HSRT, hypofractionated stereoactic radiation therapy