ATP 2016

SBRT: wide use, high heterogeneity

M. Guckenberger et al. JTO 2013: n=582, 13 institutions, SBRT 1998 - 2011

Inter- institutional variability

Number of patients Percentage Median Minimum Maximum Time- trend

Dose calculation algorithm

p<0.001 p<0.001

Type A Type B

265 249

45.5 42.8 11.7

unknown

68

Number of SBRT fractions Single fraction dose PTV encomassing (Gy)

582

3

1

20

0.02

p<0.001

582

12.5

2.9

33.0

NS p<0.001

Total dose PTV encompassing (Gy) Dose inhomogeneity (PTV encompasing dose / Maximum PTV dose) (%) Total BED dose PTV encompassing (Gy)

582

37.5

12.0

64.0 p<0.001 p<0.001

582

65

60

100

NS p<0.001

582

84.4

38.3

180.0 p<0.001 p<0.001

6 · 23. September 2016