Table 2.
Summary of gBEUD values for bladder and rectum. The bottom row shows values of the exponent a used in the calculation. A BED saturation threshold of 36 Gy was used to calculate gBEUD for HDR boost. Errors represent standard error over patients, except for cIMRT-U where two errors are shown. The first error is average end point change for one std dev envelope of DVHs, and the second error, in parantheses, is the standard error over patients for unmodified DVHs. Estimates of parameter a are based on Refs. 26, 29.
| Modality | Generalized equivalent uniform BED for late effects | ESD(Gy) | |||
|---|---|---|---|---|---|
| Bladder: ≥g3 toxicity | Rectum: ≥g2 bleeding | Rectum: ≥g3 toxicity | Rectum: ≥g3 bleeding | CTV(prostate) | |
| HDR | 16.1±3.0 | 15.3±2.3 | 21.9±2.0 | 27.6±1.5 | 45.1±3.4 |
| igIMRT | 21.9±1.6 | 17.5±1.7 | 22.2±1.5 | 26.8±1.2 | 38.4±0.4 |
| cIMRT-S | 30.1±1.4 | 22.2±1.7 | 27.5±1.5 | 31.6±1.4 | 38.4±0.8 |
| cIMRT-U | 28.1±1.0±(2.1) | 21.6±1.1±(1.7) | 26.3±1.0±(1.7) | 30.5±1.0±(1.5) | 38.3±0.1±(0.7) |
| a | 7.7 | 4.4 | 8.3 | 16.7 | – |
| α (Gy−1) | – | – | – | – | 0.16 |
| α∕β (Gy) | 3 | 3 | 3 | 3 | 3 |