Table 2 Univariable analysis of factors associated with PFS using Kaplan–Meier method.
From: Apparent diffusion coefficient as a prognostic factor in clival chordoma
Explanatory variables | Total No | No. of events | P-value |
|---|---|---|---|
Age at first operation (year) | 0.510 | ||
Younger than 50 | 18 | 7 | |
50 or older | 12 | 2 | |
Histopathology | 0.300 | ||
Chondroid | 2 | 1 | |
Classic | 28 | 8 | |
Adjuvant radiation therapy | 0.701 | ||
Proton | 13 | 4 | |
Photon | 17 | 5 | |
MRI enhancement | 0.136 | ||
Heterogenous | 20 | 8 | |
Little or none | 10 | 1 | |
Extent of tumor removal | 0.001 | ||
GTR + NTR | 22 | 3 | |
STR + PR | 8 | 6 | |
Mean ADC | < 0.001 | ||
> 1198 (10−6 mm2/s) | 19 | 1 | |
≤ 1198 (10−6 mm2/s) | 11 | 8 | |
Maximum ADC | 0.017 | ||
> 1695 (10−6 mm2/s) | 14 | 1 | |
≤ 1695 (10−6 mm2/s) | 16 | 8 | |
Minimum ADC | < 0.001 | ||
> 895.5 (10−6 mm2/s) | 17 | 0 | |
≤ 895.5 (10−6 mm2/s) | 13 | 9 | |
Brainstem extension (at first MRI) | 0.106 | ||
Yes | 24 | 9 | |
No | 6 | 0 |
