Single ‐fraction versus hypofractionated gamma knife radiosurgery for small metastatic brain tumors

AbstractStereotactic radiosurgery (SRS) has become a standard of care for the treatment of metastatic brain tumors (METs). Although a better balance of tumor control and toxicity of hypofractionated SRS (hfSRS) compared with single-fraction SRS (sfSRS) was demonstrated in large METs, there is no data comparing two approaches for small METs (<  4 cm3). It was aimed to compare clinical outcomes between sfSRS versus hfSRS Gamma Knife radiosurgery (GKRS) in a series of patients with unresected, small METs. Patients (n  = 208) treated with sfGKRS or hfGKRS between June 2017 and May 2020 were retrospectively examined in a single center. The co-primary endpoints of local control (LC) and toxicity were estimated by applying the Kaplan–Meier method. Multivariate analysis using Cox proportional hazards (HR) model ing was used to assess the effect of independent variables on the outcomes. The actuarial LC rate was 99.7% at six months and 98.8% at 18 months in the sfGKRS group, and 99.4% and 94.3% in the hfGKRS group (p = 0.089), respectively. In multivariate analysis, MET volume (p = 0.023, HR 2.064) and biologically effective dose (BED10) (p  <  0.0001, HR 0.753) was associated with LC. In total, treatment-related toxicity was observed in 13 (8.7%) patients during a median period of 10 weeks (range 1–31). Radiation necrosis was observed in four patients (1.9%), and all patients were in the sfGKRS group (p = 0.042). Only the maximu m dose was associated...
Source: Clinical and Experimental Metastasis - Category: Cancer & Oncology Source Type: research