TABLE IV.
Multivariate analysis of factors related to the development of grades 3 and 4 acute gastrointestinal toxicity
| Characteristic | Value | OR | 95% CI | p Valuea |
|---|---|---|---|---|
| Age (years) | ||||
| Median | 58 | 0.996 | 0.675 | 0.979 to 1.014 |
| Range | 27–76 | |||
| Sex (n) | ||||
| Men | 169 | 0.938 | 0.557 to 1.582 | 0.811 |
| Women | 111 | |||
| Tumour location (n) | ||||
| Head | 187 | 1.267 | 0.74 to 2.17 | 0.388 |
| Body or tail | 93 | |||
| Tumour size (cm) | ||||
| Median | 4.1 | 1.115 | 0.944 to 1.318 | 0.200 |
| Range | 5.1–2.0 | |||
| Gemcitabine chemotherapy after RT (n) | ||||
| <1 Month | 134 | 0.806 | 0.485 to 1.338 | 0.404 |
| ≥1 Month | 146 | |||
| Planning target volume (cm3) | ||||
| Median | 184.83 | 0.997 | 0.988 to 1.006 | 0.516 |
| Range | 133.79–241.85 | |||
| Bowel V45 (cm3) | ||||
| Median | 41.37 | 0.995 | 0.973 to 1.018 | 0.693 |
| Range | 20.02–59.41 | |||
| Karnofsky PS (n) | ||||
| <80 | 194 | 0.787 | 0.456 to 1.358 | 0.389 |
| ≥80 | 86 | |||
| RT technique (n) | ||||
| 3D-CRT | 137 | |||
| IMRT | 97 | 3.384 | 1.469 to 7.798 | 0.004 |
| RapidArcb | 46 | 2.563 | 1.075 to 6.113 | 0.034 |
a
By logistic regression analysis.
b
Varian Medical Systems, Palo Alto, CA, U.S.A.
OR = odds ratio; CI = confidence interval; RT = radiotherapy; V45 = volume receiving 45% or more of the prescribed dose; PS = performance status; 3D-CRT = 3-dimensional conformal radiotherapy; IMRT = intensity-modulated radiotherapy.