706 / 1578
•
Treatment constraints:
Ø
PTV = GTV + 5mm
Ø
Dose prescription
§
Centrally located lesions
§
Lesions < 1cm from thoracic wall
§
Peripheral lesions
Ø
Dose prescription
§
Normalization: 100% @
isocentre
, D
2%
< 105%
§
95% of PTV covered by
prescription isodose
surface (i.e. 12 or 17Gy)
§
99% of PTV covered by 90% of
prescription isodose
surface
Ø
Dose constraints:
§
Conformity, low and high dose spillage …
§
Normal tissues …
Pencil Beam versus Monte Carlo Dose Calculation
4 x 12 Gy (Monte Carlo)
3 x 17 Gy (Monte Carlo)
•
Type B dose calculation algorithm: XVMC
SBRT 2017 - D. Verellen
PTV &
tissue heterogeneity &
dose prescription