2017_SBRT_Course Book

Reporting dose

• Dose prescription and margins in SRS • 2 lesions, treated to 25Gy covering 97% of the target Ø 8mm ϕ lesion, 8mm collimator , 25Gy @ 80% : § D max = 31.3 Gy / D mean = 27.5Gy Ø 11mm ϕ lesion, 8mm collimator , 25Gy @ 50% : § D max = 50.0 Gy / D mean = 35.0Gy • Same lesion, same dose prescription, variable isodose:

48% difference in dose SBRT 2017 - D. Verellen

I. Paddick et al.