Up to Four-Year Outcomes of Single-Fraction Stereotactic Radiosurgery for Small Brain Metastases: A Competing-Risk Analysis.
Radioresistant brain metastases had much higher local treatment failure after single-fraction radiosurgery.
Up to Four-Year Outcomes of Single-Fraction Stereotactic Radiosurgery for Small Brain Metastases: A Competing-Risk Analysis.
Single-fraction stereotactic radiosurgery (stereotactic radiosurgery) is recommended for small brain metastases (< 2 cm).
With prior radiotherapy or surgery to the index lesion were excluded.
radioresistant tumors failed local control far more often, worse tumor control
Thirty-three tumors were radioresistant and 39 radiosensitive.
OS was 42% (95% CI, 28%-63%) and 36% (95% CI, 24%-55%), and PFS was 19% (95% CI, 9%-40%) and 23% (95% CI, 13%-41%), respectively.
Radioresistant histology was associated with higher local treatment failure hazard (cause-specific hazard ratios 3.19; subdistribution hazard ratios 3.91) and lower hazards of death without prior local treatment failure (cause-specific hazard ratios 0.37; subdistribution hazard ratios 0.24), with no significant effect on OS or PFS.
Local control after 18 Gy stereotactic radiosurgery is poor in radioresistant brain metastases.
Higher local treatment failure incidence is amplified by lower competing mortality, highlighting the interplay between tumor biology and survival.
These findings support competing risk-based analyses and consideration of alternative dose-escalation for high-risk tumors.