Table 1. Baseline Patient Characteristics by Dose-Fractionated Radiotherapy Regimen.
| Characteristic | No. (%) | P valuea | ||
|---|---|---|---|---|
| Conventional fractionation (n = 80) | Moderate hypofractionation (n = 55) | Ultrahypofractionation (n = 62) | ||
| Age, mean (SD), y | 67 (12) | 67 (14) | 72 (10) | .02 |
| Female sex | 56 (70.0) | 46 (83.6) | 32 (51.6) | <.001 |
| White race | 59 (73.8) | 44 (80.0) | 46 (74.2) | .67 |
| CVD diagnosis | ||||
| Rheumatoid arthritis | 25 (31.3) | 21 (38.2) | 28 (45.2) | .12 |
| Systemic lupus erythematosus | 20 (25.0) | 6 (10.9) | 8 (12.9) | |
| Psoriasis | 26 (32.5) | 15 (27.3) | 13 (21.0) | |
| Scleroderma | 1 (1.2) | 4 (7.3) | 3 (4.8) | |
| Other | 8 (10.0) | 9 (16.4) | 10 (16.1) | |
| CVD medication received | ||||
| Anyb | 56 (70.0) | 36 (65.5) | 29 (46.8) | .01 |
| Steroid | 15 (18.8) | 7 (12.7) | 9 (14.5) | .61 |
| CVD activity during radiotherapy | ||||
| Controlled | 60 (75.0) | 41 (74.5) | 47 (75.8) | .75 |
| Low | 19 (23.8) | 12 (21.8) | 12 (19.4) | |
| Moderate to high | 1 (1.2) | 2 (3.6) | 3 (4.8) | |
| Cancer diagnosisc | ||||
| Breast | 22 (27.5) | 29 (52.7) | 4 (6.5) | <.001 |
| Lung | 4 (5.0) | 3 (5.5) | 14 (22.6) | |
| Genitourinary | 4 (5.0) | 1 (1.8) | 21 (33.9) | |
| Head and neck | 13 (16.3) | 5 (9.1) | 4 (6.5) | |
| Radiotherapy sitec | ||||
| Breast | 22 (27.5) | 25 (45.5) | 1 (1.6) | <.001 |
| Thorax | 8 (10.0) | 3 (5.5) | 14 (22.6) | |
| Prostate | 4 (5.0) | 0 | 19 (30.6) | |
| Central nervous system | 10 (12.5) | 5 (9.1) | 9 (14.5) | |
| Treatment technique | ||||
| 3D-CRTd | 27 (33.8) | 32 (58.2) | 0 | <.001 |
| IMRT | 47 (58.8) | 12 (21.8) | 0 | |
| Electron therapy | 1 (1.3) | 2 (3.6) | 0 | |
| Brachytherapy | 0 | 8 (14.5) | 14 (22.6) | |
| SBRT | 0 | 0 | 48 (77.4) | |
| PTV, mean (SD), mL | 3648 (17 190) | 668 (1665) | 156 (492) | .18 |
| BED-10, mean (SD), Gy | 64.2 (16.7) | 54.6 (15.5) | 84.8 (11.2) | .03 |
Abbreviations: 3D-CRT, 3-dimensional conformal radiotherapy; BED-10, biological effective dose with α/β ratio of 10; CVD, collagen vascular disease; IMRT, intensity-modulated radiotherapy; PTV, planning target volume; SBRT, stereotactic body radiotherapy.
For categorical variables, P values were obtained using χ2 or Fisher exact tests, as appropriate. For continuous variables, P values were obtained using 1-way analysis of variance.
Any CVD medication includes both disease-modifying antirheumatic drugs and steroidal medications. Among 80 patients receiving conventionally fractioned radiotherapy, 55 patients receiving moderately hypofractionated radiotherapy, and 62 patients receiving ultrahypofractionated radiotherapy, 24 patients, 19 patients, and 33 patients, respectively, were not receiving any medications to specifically treat CVD.
The 4 most common sites in the cohort are listed.
Data were missing for 5 patients receiving conventionally fractionated radiotherapy and 1 patient receiving moderately hypofractionated radiotherapy.