Table 1.
Patient and treatment characteristics
| Characteristic | All (n = 210) | Standard field (n = 164) | Limited field (n = 46) | P |
|---|---|---|---|---|
| Age (y), median (range) | 57 (21-82) | 57 (21-82) | 57 (21-75) | .890 |
| KPS, median (range) | 80 (50-100) | 80 (50-100) | 80 (50-100) | .241 |
| KPS, n (%) | .219 | |||
| >70 | 125 (60) | 94 (57) | 31 (67) | |
| ≤70 | 85 (40) | 70 (43) | 15 (33) | |
| Sex (%) | .780 | |||
| Male | 127 (60) | 100 (61) | 27 (59) | |
| Female | 83 (40) | 64 (39) | 19 (41) | |
| Race, n (%) | .312 | |||
| White | 196 (93) | 151 (92) | 45 (98) | |
| Other | 14 (7) | 13 (8) | 1 (2) | |
| EOR, n (%) | .584 | |||
| Biopsy | 32 (15) | 26 (16) | 6 (13) | |
| STR | 55 (26) | 45 (27) | 10 (22) | |
| GTR | 123 (59) | 93 (57) | 30 (65) | |
| MGMT status, n (%) | <.001 | |||
| Known | 161 (77) | 115 (70) | 46 (100) | |
| Unknown | 49 (23) | 49 (30) | 0 | |
| MGMT methylated, n (%)* | .645 | |||
| Yes | 62 (38) | 43 (37) | 19 (41) | |
| No | 99 (62) | 72 (63) | 27 (59) | |
| Baseline TLC (cells/μL), median (range) | 1400 (300-4200) | 1400 (400-4200) | 1500 (300-3500) | .874 |
| Baseline Dex use (mg/day), median (range) | 4 (0-24) | 4 (0-16) | 1 (0-24) | .157 |
| Baseline Dex use > 4 mg/day, n (%) | .934 | |||
| Yes | 42 (20) | 33 (20) | 9 (20) | |
| No | 168 (80) | 131 (80) | 37 (80) | |
| Additional agent/placebo during RT, n (%) | .002 | |||
| Yes | 25 (12) | 25 (15) | 0 | |
| No | 185 (88) | 139 (85) | 46 (100) | |
| RT technique, n (%) | .001 | |||
| 3D-CRT | 28 (13) | 28 (17) | 0 | |
| IMRT | 182 (87) | 136 (83) | 46 (100) | |
| GTV (cm3),* median (range) | [n = 184] 33.3 (5.4-250.3) |
[n = 145] 32.0 (5.4-134.3) |
[n = 39] 48.4 (7.6-250.3) |
.014 |
| PTV initial (cm3),* median (range) | [n = 200] 334.0 (50-1225) |
[n = 155] 375 (50-1225) |
[n = 45] 245.7 (112.8-622.4) |
<.001 |
| PTV boost (cm3),* median (range) | [n = 198] 216.3 (50-690.6) |
[n = 155] 230.5 (50-690.6) |
[n = 43] 156.9 (76.1-622.4) |
<.001 |
| Brain DVH (%),* median (range) | [n = 200] | [n = 155] | [n = 45] | |
| V10 Gy | 77 (37-100) | 80 (42-100) | 68 (37-96) | <.001 |
| V15 Gy | 66 (31-100) | 68 (35-100) | 56 (31-90) | <.001 |
| V20 Gy | 57 (24-100) | 60 (27-100) | 48 (24-83) | <.001 |
| V25 Gy | 50 (19-100) | 53 (21-100) | 41 (19-78) | <.001 |
| V30 Gy | 45 (15-100) | 47 (18-100) | 34 (15-74) | <.001 |
| V35 Gy | 39 (13-100) | 42 (15-100) | 30 (13-68) | <.001 |
| V40 Gy | 35 (11-99) | 37 (13-99) | 26 (11-63) | <.001 |
| V45 Gy | 31 (10-98) | 33 (12-98) | 24 (10-58) | <.001 |
| V50 Gy | 27 (8-95) | 29 (10-95) | 21 (8-51) | <.001 |
| V55 Gy | 22 (7-86) | 23 (7-86) | 19 (7-45) | .001 |
| V60 Gy | 14 (3-52) | 14 (3-52) | 13 (5-32) | .183 |
Abbreviations: 3D-CRT = 3-dimensional conformal radiation therapy; Dex = dexamethasone; DVH = dose—volume histogram; EOR = extent of resection; GTR = gross total resection; GTV = gross tumor volume (GTV for standard-field RT cohort represents the boost GTV); IMRT = intensity modulated radiation therapy; KPS = Karnofsky performance status; MGMT = O6-methylguanine-DNA-methyltransferase; PTV = planning target volume; RT = radiation therapy; STR = subtotal resection; TLC = total lymphocyte count; V10-60 Gy = brain volume receiving 10-60 Gy.
*
Variables with missing values: MGMT methylation (49 patients), GTV (26 patients), PTV initial (10 patients), PTV boost (12 patients), brain DVH (10 patients).