Table 1.
Patient and Lesion Characteristics
| Variables by patient | SRS alone (%) N = 143 | SRS-ICI (%) N = 36 | P-value |
|---|---|---|---|
| Median Follow up (q1, q3) | 10.3 (5.8, 12.0) | 7.7 (4.2, 12.0) | 0.08 |
| Median age (q1, q3) | 60 (54, 67) | 59 (55, 71) | 0.65 |
| Race | |||
| White | 95 (66) | 26 (72) | 0.51 |
| Other | 48 (34) | 10 (28) | |
| KPS | |||
| 80–100 | 105 (73) | 29 (81) | 0.38 |
| 50–70 | 38 (27) | 7 (19) | |
| Primary Site | |||
| Lung | 75 (52) | 22 (61) | 0.35 |
| Other | 68 (48) | 14 (39) | |
| Histology | |||
| Renal cell | 9 (6.3) | 3(8.3) | < 0.001 |
| Melanoma | 3 (2.1) | 7 (19.5) | |
| Squamous cell | 11(7.7) | 6 (16.7) | |
| Adenocarcinoma | 91 (63.6) | 17 (47.2) | |
| Other | 29 (20.3) | 3 (8.3) | |
| Active Extra-CNS Disease | 0.36 | ||
| Extensive | 62 (43) | 20 (56) | |
| Bone only | 8 (6) | 3 (8) | |
| Primary only | 41 (29) | 9 (25) | |
| None | 32 (22) | 4 (11) | |
| Prior WBRT | 0.01 | ||
| Yes | 49 (34) | 4 (11) | |
| No | 94 (66) | 32 (89) | |
| Variables by lesion | SRS alone (%) N = 286 | SRS-ICI (%) N = 99 | P-value |
| Tumor size | 0.03 | ||
| ≤ 2 cm | 226 (79) | 88 (89) | |
| > 2 cm | 60 (21) | 11 (11) | |
| SRS fractions | |||
| Single fraction | 203 (71) | 77 (78) | 0.19 |
| Multi-fraction | 83 (29) | 22 (22) | |
| Surgical Resection | |||
| No | 265 (93) | 93 (94) | 0.67 |
| Yes | 21 (7) | 6 (6) | |
| Concurrent Systemic therapy | 0.007 | ||
| Yes | 68 (24) | 11 (11) | |
| No | 218 (76) | 88 (89) | |
| Prior WBRT | 0.004 | ||
| Yes | 108 (37.8) | 22 (22.2) | |
| No | 178 (62.2) | 77 (77.8) | |
| Histology | < 0.001 | ||
| Renal cell | 14 (4.9) | 15 (15.1) | |
| Melanoma | 12 (4.2) | 20 (20.2) | |
| Squamous cell | 18 (6.3) | 10 (10.1) | |
| Adenocarcinoma | 185 (64.7) | 48 (48.5) | |
| Other | 57 (19.9) | 6 (6.1) | |
| Median Prescription Dose for SRS (single fraction) | 21 (20, 24) | 24 (21, 24) | < 0.001 |
| Median Biologically Equivalent Dose for SRT (multiple fraction) | 38 (36, 43) | 50 (38, 51) | 0.002 |