Table 1.
Patient, tumor, and treatment characteristics of the total, frame, and mask immobilization cohorts.
| Total Cohort (% or Range) | Frame Immobilization Cohort (% or Range) | Mask Immobilization Cohort (% or Range) | p-Value | |
|---|---|---|---|---|
| Number of patients | 150 | 93 | 57 | |
| Median age, years | 65 (28–90) | 65 (28–90) | 66 (28–89) | 0.876 |
| Sex | 0.398 | |||
| Female | 86 (57.3) | 56 (60.2) | 30 (52.6) | |
| Male | 64 (42.7) | 37 (39.8) | 27 (47.4) | |
| Race | 0.052 | |||
| White | 137 (91.3) | 89 (95.7) | 48 (84.2) | |
| African American | 10 (6.7) | 3 (3.2) | 7 (12.3) | |
| Other | 3 (2.0) | 1 (1.1) | 2 (4.5) | |
| Extracranial disease | 0.113 | |||
| No | 109 (24.1) | 71 (21.9) | 38 (29.4) | |
| Yes | 344 (75.9) | 253 (78.1) | 91 (80.6) | |
| Status of extracranial disease | 0.143 | |||
| Stable | 201 (44.4) | 151 (46.6) | 50 (38.8) | |
| Progressive | 252 (55.6) | 173 (53.4) | 79 (61.2) | |
| Median KPS | 90 (60–100) | 90 (60–100) | 90 (60–100) | 0.184 |
| Primary tumor histology | 0.024 | |||
| Lung | 252 (55.6) | 176 (54.3) | 76 (58.9) | |
| Breast | 82 (18.1) | 54 (16.7) | 28 (21.7) | |
| Gastrointestinal | 43 (9.5) | 39 (12.0) | 4 (3.1) | |
| Other | 76 (16.8) | 55 (16.9) | 21 (16.3) | |
| Number of SRS courses | 189 | 115 | 74 | |
| Number of brain metastases | 453 | 324 | 129 | |
| Median number of brain metastases treated per SRS course | 6 (1–23) | 7 (1–23) | 3 (1–14) | <0.001 |
| SRS prescription dose | 0.086 | |||
| 22 Gy | 107 (23.6) | 84 (25.9) | 23 (17.8) | |
| 24 Gy | 346 (76.4) | 240 (74.1) | 106 (82.2) | |
| Prescription Isodose Line (%) | 56 (50–94) | 56 (50–94) | 55 (50–94) | 0.860 |
| Median maximal tumor diameter, cm | 0.8 (0.5–1.95) | 0.73 (0.5–1.95) | 0.8 (0.5–1.95) | 0.068 |
| Median tumor volume, cm3 | 0.18 (0.01–3.5) | 0.16 (0.01–3.5) | 0.18 (0.02–2.47) | 0.054 |