Table 2.
Magnetic Resonance Imaging Features
| Imaging feature | Number | Log-rank | Weighted log-rank | Median PFS (95% CI) | 1-year and 2-year PFS rate | ||
|---|---|---|---|---|---|---|---|
| Chi-square | P value | Chi-square | P value | ||||
| Multifocality | 7.410 | .025 | 6.813 | .033 | |||
| 1 tumor | 49 (75.4%) | 22.0 (16.8–20.5) | 41 (83.7%), 23 (46.9%) | ||||
| 2 tumors | 12 (18.5%) | 15.0 (12.1–20.6) | 9 (75.0%), 3 (25.0%) | ||||
| 3 tumors | 4 (6.2%) | 10.5 (0.2–20.8) | 2 (50.0%), 0 | ||||
| Observation size | 0.203 | .65 | 0.103 | .75 | |||
| <2 cm | 28 (43.1%) | 23.5 (16.1–21.4) | 24 (85.7%), 14 (50.0%) | ||||
| ≥2 cm | 37 (56.9%) | 18.0 (14.8–19.2) | 28 (75.7%), 12 (32.4%) | ||||
| APHE | 0.066 | .79 | 0.296 | .59 | |||
| Absent | 6 (9.2%) | 21.5 (8.1–26.5) | 4 (66.7%), 3 (50.0%) | ||||
| Present | 59 (90.8%) | 19.0 (16.1–19.5) | 48 (81.4%), 23 (39.0%) | ||||
| Heterogeneity of APHE | 0.293 | .86 | 1.029 | .60 | |||
| Absent | 6 (9.2%) | 21.5 (8.1–26.5) | 4 (66.7%), 3 (50.0%) | ||||
| Homogeneous | 30 (46.2%) | 21.5 (14.8–20.3) | 22 (73.3%), 13 (43.3%) | ||||
| Heterogeneous | 29 (44.6%) | 18.0 (15.8–20.2) | 26 (89.7%), 10 (34.5%) | ||||
| Nonperipheral “washout” | 0.034 | .85 | 0.011 | .92 | |||
| Absent | 15 (23.1%) | 22.0 (13.2–21.6) | 11 (73.3%), 7 (46.7%) | ||||
| Present | 50 (76.9%) | 19.0 (16.0–19.7) | 41 (82.0%), 19 (38.0%) | ||||
| Enhancing “capsule” | 3485 | .06 | 3425 | .06 | |||
| Absent | 19 (29.2%) | 24.0 (18.1–23.7) | 17 (89.5%), 12 (63.2%) | ||||
| Present | 46 (70.8%) | 16.5 (14.5–18.4) | 35 (76.1%), 14 (30.4%) | ||||
| Continuity of an enhancing “capsule” | 6.379 | .041 | 8.918 | .012 | |||
| Absent | 19 (29.2%) | 24.0 (18.1–23.7) | 17 (89.5%), 12 (63.2%) | ||||
| Discontinuous | 31 (47.7%) | 17.0 (15.7–19.5) | 27 (87.1%), 9 (29.0%) | ||||
| Continuous | 15 (23.1%) | 13.0 (9.12–18.88) | 8 (53.3%), 5 (33.3%) | ||||
Note–Survival times were analyzed using a univariate log-rank test. Furthermore, the log-rank test was weighted toward earlier events by assessment within the first 24 months after treatment and using the Gehan-Breslow-Wilcoxon test. When evaluating PFS for the first 2 years by imaging features, patients with 1, 2, and 3 tumors survived a median of 22.0 months (95% CI, 16.8–20.5), 15.0 months (95% CI, 12.1–20.6), and 10.5 months (95% CI, 0.2–20.8), respectively. The 1-year and 2-year rates for patients with 1 tumor were 83.7% and 46.9%, respectively, those for patients with 2 tumors were 75.0% and 25.0%, respectively, and those for patients with 3 tumors were 50.0% and 0, respectively.
APHE = arterial phase hyperenhancement; CI = confidence interval; PFS = progression-free survival.