Patient characteristics and treatment parameters

VariableSRS and ipilimumabSRS and nivolumab
N = 45N = 35p
Sex (F/M)17/2814/211.0
Age (years)
BRAF mutation0.8
Extracranial disease0.7
Number of metastases0.4
Type of SRS0.76
 Single-fraction SRS153132
 Fractionated SRS2219
Size of metastases0.8
  < 2 cm9984
 2–3 cm4638
  ≥ 3 cm3029
Total tumor volume (cm3)0.1
GTV (cm3)0.6
PTV (cm3)0.3
Conformity indexa0.5

SRS stereotactic radiosurgery, KPS Karnofsky Performance Status

DS-GPA Diagnosis-Specific Graded Prognostic Factors, GTV Gross Target Volume

PTV Planning Target Volume, acalculated as prescribed isodose volume/tumor volume

encompassed by the prescription isodose volume