Table 2.
Patient and dosimetry characteristics after propensity score matching
| Parameter | CyberKnife (n = 35) | VMAT (n = 35) | p Value |
|---|---|---|---|
| Age (years) | 71.7 ± 6.3 | 71.8 ± 5.8 | 0.953 |
| Clinical T stage | 0.50 | ||
| 1c-2a | 14 (40%) | 18 (51%) | |
| 2b-2c | 14 (40%) | 9 (26%) | |
| 3a | 7 (20%) | 8 (23%) | |
| IPSA (ng/mL) | 0.70 | ||
| < 10 | 20 (57%) | 23 (66%) | |
| 10–20 | 10 (29%) | 7 (20%) | |
| > 20 | 5 (14%) | 5 (14%) | |
| Gleason score | 0.775 | ||
| 6 | 3 (8%) | 5 (14%) | |
| 7 | 24 (69%) | 21 (60%) | |
| 8–10 | 8 (23%) | 9 (26%) | |
| Risk group | 0.82 | ||
| Low | 2 (5.7%) | 4 (11.4%) | |
| Intermediate | 19 (54.3%) | 17 (48.6%) | |
| High | 14 (40%) | 14 (40%) | |
| Neoadjuvant ADT | 33 (94.3%) | 31 (88.6%) | 0.673 |
| Duration of neoadjuvant ADT (months) | 6.4 ± 3.2 | 6.3 ± 0.8 | 0.867 |
| Comorbidity | |||
| Antithrombotic therapy | 5 (14.3%) | 6 (17.1%) | 0.99 |
| Diabetes | 5 (14.3%) | 4 (11.4%) | 0.99 |
| Previous TURP | 0 (0%) | 1 (2.9%) | 0.99 |
| Medication to improve dysuria at baseline | 7 (20%) | 7 (20%) | 0.99 |
| Pre-treatment IPSS | 0.939 | ||
| Mild (0–7) | 10 (28.6%) | 12 (34.3%) | |
| Moderate (8–19) | 21 (60.0%) | 19 (54.3%) | |
| Severe (20–35) | 4 (11.4%) | 4 (11.4%) | |
| Median follow-up (years) | 3.0 (1.1–4.6) | 2.9 (1.6–4.2) | 0.36 |
| Prostate volume (cc) | 25.3 ± 9.3 | 25.3 ± 15.5 | 0.997 |
| PTV volume (cc) | 47.3 ± 13.0 | 62.4 ± 23.9 | 0.002 |
| PTV D98% (Gy) | 35.4 ± 0.30 | 35.8 ± 0.15 | < 0.001 |
| PTV Dmedian (Gy) | 41.8 ± 0.76 | 37.1 ± 0.20 | < 0.001 |
| PTV D2% (Gy) | 44.0 ± 0.80 | 37.7 ± 0.24 | < 0.001 |
| Bladder volume (cc) | 191.0 ± 44.8 | 237.5 ± 102.5 | 0.0165 |
| Bladder Dmean (Gy) | 9.75 ± 1.64 | 9.74 ± 2.43 | 0.979 |
| Bladder D0.5 cc (Gy) | 39.7 ± 1.10 | 37.5 ± 0.18 | < 0.001 |
| Bladder Dmax (Gy) | 41.9 ± 1.40 | 37.8 ± 0.19 | < 0.001 |
| Urethra Dmean (Gy) | 36.0 ± 0.18 | 37.1 ± 0.30 | < 0.001 |
| Urethra D0.1 cc (Gy) | 36.2 ± 0.22 | 37.4 ± 0.37 | < 0.001 |
| Urethra Dmax (Gy) | 37.1 ± 0.40 | 37.5 ± 0.40 | 0.002 |
| Rectal Dmean (Gy) | 9.80 ± 1.75 | 9.80 ± 1.76 | 0.99 |
| Rectal D0.5 cc (Gy) | 35.6 ± 1.45 | 36.3 ± 1.31 | 0.034 |
| Rectal Dmax (Gy) | 38.9 ± 0.89 | 37.4 ± 0.50 | < 0.001 |
Data are presented as median (range), mean ± SD, or number (%)
VMAT volumetric modulated arc therapy; IPSA initial prostate-specific antigen; ADT androgen deprivation therapy; TURP transurethral resection of the prostate; IPSS International Prostate Symptom Score; PTV planning target volume; Dmedian median dose; Dx% dose covering x% of the target volume; Dmean mean dose; Dx cc dose to x cc of the organ; Dmax maximum dose