Table 3.
Multivariate analysis predicting acute genitourinary toxicity (n = 122)
| Covariate | OR | 95% CI | OR P valuea |
|---|---|---|---|
| Treatment | |||
| VMAT | 0.18 | 0.07–0.44 | <.001 |
| IMRT (ref) | — | — | — |
| V40 bladder | 1.00 | 0.97–1.03 | .934 |
| V65 bladder | 1.05 | 1.00–1.10 | .076 |
| V70 bladder | 0.96 | 0.90–1.01 | .135 |
| Region treated | |||
| Prostate + LNs | 0.49 | 0.18–1.34 | .166 |
| Prostate only (ref) | — | — | — |
| T stage | |||
| T1 | 1.91 | 0.86–4.27 | .113 |
| T2/3 (ref) | — | — | — |
| Gleason score: | |||
| 6 | 0.29 | 0.08–1.10 | .069 |
| 7 | 0.38 | 0.13–1.08 | .07 |
| 8 + (ref) | — | — | — |
| Prescribed RT dose (Gy) | 1.14 | 0.96–1.34 | .131 |
| PTV volume (cc) | 1.00 | 0.99–1.00 | .217 |
CI, confidence interval; IMRT, intensity modulated radiation therapy; LNs, lymph nodes; OR, odds ratio; ref, reference; PTV, planning target volume; RT, radiation therapy; VMAT, volumetric modulated arc therapy.
a
The probability of having more toxicity is modeled.