borderline significancep = 0.066
The effect of PTV on DPFS was significant in the 18 months after SBRT, where each twofold increase in total PTV increased the risk of distant progression by 40.6% (95% CI: 28.1–54.3%, p <0.0001) in the first 6 months, by 11.6% with borderline significance during months 6–12 (95% CI: −0.7–25.4%, p = 0.066), and by 18.2% in months 12–18 (95% CI: 2.2–36.7%, p = 0.024).