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Accumulated dose
a case study (1)
•
Treatment approach re-irradiation:
•
Previous irradiation (TomoTherapy):
23 x 1.8 Gy = 41.4 Gy
•
Re-irradiation (TomoTherapy):
15 x 2.5 Gy = 37.5 Gy
•
Dose distribution adapted/compromised based on
accumulated dose accounting for spinal cord tolerances.
•
Assumption
s:
No recovery (previous irradiation late 2015, re-irradiation early
2016)
Spinal cord tolerance:
50 Gy EQD
2/2
(2 Gy equivalent dose with α/β = 2: )
re-irradiation 2017 - D. Verellen
EQD
2/2
=
D
´
d
+
a
/
b
2
+
a
/
b