Table 1.
Patient characteristics
| Characteristic | RFA (n=178) | SBRT (n=44) | p-value |
|---|---|---|---|
| Age (yr) | |||
| ≤ 70 | 144 (80.9) | 36 (81.8) | 0.89 |
| > 70 | 34 (19.1) | 8 (18.2) | |
| Mean±SD | 60.8±10.9 | 60.3±9.9 | 0.80 |
| Male sex | 130 (73.0) | 31 (70.5) | 0.73 |
| ECOG score ≤ 1 | 177 (99.4) | 44 (100) | > 0.99 |
| Primary tumor location | |||
| Left colona) | 41 (23.0) | 7 (15.9) | 0.20 |
| Right colonb) | 29 (16.3) | 12 (27.3) | |
| Rectum | 108 (60.7) | 25 (56.8) | |
| Primary tumor differentiation | |||
| Well | 15 (8.8) | 4 (9.5) | 0.86 |
| Moderate | 145 (85.3) | 37 (88.1) | |
| Poor | 10 (5.9) | 1 (2.4) | |
| Timing of liver metastasis | |||
| Synchronous | 62 (34.8) | 24 (54.6) | 0.016 |
| Metachronous | 116 (65.2) | 20 (45.4) | |
| Pre-treatment systemic therapy (yes) | 139 (78.1) | 38 (86.4) | 0.22 |
| Post-treatment systemic therapy (yes) | 132 (74.2) | 30 (68.2) | 0.42 |
| CEA < 6 ng/mL | 137 (77.0) | 31 (70.5) | 0.37 |
| No. of liver metastases | |||
| 1 | 120 (67.4) | 30 (68.2) | 0.48 |
| 2 | 40 (22.5) | 10 (22.7) | |
| 3 | 10 (5.6) | 4 (9.1) | |
| ≥ 4 | 8 (4.5) | 0 | |
| Liver tumor size (per-lesion) (cm) | |||
| ≤ 2 | 211 (78.7) | 22 (35.5) | < 0.001 |
| > 2 | 57 (21.3) | 40 (64.5) | |
| Mean±SD | 1.54±0.74 | 2.31±0.79 | < 0.001 |
Values are presented as number (%) unless otherwise indicated. CEA, carcinoembryonic antigen; ECOG, Eastern Cooperative Oncology Group; RFA, radiofrequency ablation; SBRT, stereotactic body radiation therapy; SD, standard deviation.
a)
From the cecum to the proximal half of the transverse colon,
b)
From the distal half of the transverse colon to the sigmoid colon.