Table 2.
Treatment characteristics
| CFRT (n = 58) | SBRT (n = 191) | Total (n = 249) | P-value | |
|---|---|---|---|---|
| Age at RT (y) | <.01 | |||
| Median (range) | 75.3 (52.7-92.3) | 70.6 (48.2-88.3) | 71.6 (48.2-92.3) | |
| PSA at RT (ng/mL) | <.01 | |||
| Median (range) | 6.1 (0.1-2794.0) | 1.7 (0.1-28.9) | 2.5 (0.1-2794.0) | |
| PSA value (ng/mL), n (%) | <.01 | |||
| 0-5 | 26 (44.8) | 140 (73.7) | 166 (66.9) | |
| 5-10 | 7 (12.1) | 31 (16.3) | 38 (15.3) | |
| 10-20 | 9 (15.5) | 13 (6.8) | 22 (8.9) | |
| >20 | 16 (27.6) | 6 (3.2) | 22 (8.9) | |
| Unknown | 0 | 1 (0.5) | 1 (0.4) | |
| Castrate-resistant, n (%) | .39 | |||
| No | 38 (65.5) | 113 (59.2) | 151 (60.6) | |
| Yes | 20 (34.5) | 78 (40.8) | 98 (39.4) | |
| Number of metastases at RT, n (%) | <.01 | |||
| 1 | 14 (24.1) | 120 (62.8) | 134 (53.8) | |
| 2 | 5 (8.6) | 27 (14.1) | 32 (12.9) | |
| 3 | 4 (6.9) | 15 (7.9) | 19 (7.6) | |
| 4 | 1 (1.7) | 6 (3.1) | 7 (2.8) | |
| ≥5 | 34 (58.6) | 23 (12.0) | 57 (22.9) | |
| Site treated, n (%) | .09 | |||
| Spine | 23 (39.7) | 82 (42.9) | 105 (42.2) | |
| Pelvis | 13 (22.4) | 64 (33.5) | 77 (30.9) | |
| Extremity | 15 (25.9) | 22 (11.5) | 37 (14.9) | |
| Sternum | 2 (3.4) | 7 (3.7) | 9 (3.6) | |
| Rib | 5 (8.6) | 16 (8.4) | 21 (8.4) | |
| Dose (Gy), n (%) | <.01 | |||
| 8 | 33 (56.9) | 0 | 33 (13.3) | |
| 10 | 1 (1.7) | 0 | 1 (0.4) | |
| 16 | 0 | 7 (3.7) | 7 (2.8) | |
| 18 | 0 | 87 (45.5) | 87 (34.9) | |
| 20 | 24 (41.4) | 89 (46.6) | 113 (45.4) | |
| 24 | 0 | 8 (4.2) | 8 (3.2) | |
| PTV (cm3) | <.01 | |||
| Median (range) | 228.3 (12.9-1665.3) | 33.0 (4.7-561.7) | 41.7 (4.7-1665.3) | |
| BED | <.01 | |||
| Median (range) | 29.3 (29.3-46.7) | 153.3 (101.3-216.0) | 126.0 (29.-216.0) | |
| Pre-RT systemic therapy, n (%) | .26 | |||
| H + C | 22 (37.9) | 62 (32.5) | 84 (33.7) | |
| H | 29 (50.0) | 85 (44.5) | 114 (45.8) | |
| C | 1 (1.7) | 2 (1.0) | 3 (1.2) | |
| None | 6 (10.3) | 42 (22.0) | 48 (19.3) | |
| Peri-RT systemic therapy, n (%) | .02 | |||
| H + C | 6 (10.3) | 10 (5.2) | 16 (6.4) | |
| H | 38 (65.5) | 94 (49.2) | 132 (53.0) | |
| C | 2 (3.4) | 5 (2.6) | 7 (2.8) | |
| None | 12 (20.7) | 82 (42.9) | 94 (37.8) |
Abbreviations: BED = biologically effective dose; C = chemotherapy; CFRT = conventionally fractionated radiation therapy; H = hormonal therapy; PSA = prostate-specific antigen; PTV = planning target volume; RT = radiation therapy; SBRT = stereotactic body radiation therapy.