1237 / 1578
/
Study # events
OAR
definition
Dose in patients with
radiation myelopathy Conclusion
Ryu
2006
1 / 177
SC 6mm CC
of TV
9.6Gy to 10%
10% < 10Gy
Gibbs
2009
6 / 1075
NS
D
max
8.5 – 26.2Gy
1cm
3
< 8Gy
Sahgal
2010
5 / 24
case control study
Thecal sack
D
max
median 59Gy (nBED
2/2
)
D
max
below
thresholds using
LQ model
Safety of spine SBRT: myelopathy
• (Very) Few patients developed radiation induced myelopathy
• Dose – response inconclusive
• However: follow-up short in majority of patients
ESTRO SBRT 2017 - Matthias Guckenberger
15
07.09.17
/
Safety of spine SBRT: myelopathy
Multi-institutional analysis:
• 9 cases with radiation induced myelopathy
• 66 cases w/o radiation induced myelopathy
Sahgal IJROBP 2012
1 fraction 3 fractions 5 fractions
1%probability
9.2
14.8
18.2
2%probability
10.7
17.4
21.5
3%probability
11.5
18.8
23.1
4%probability
12
19.6
24.4
5%probability
12.4
20.3
25.3
• Doses converted to 2Gy equivalent dose (EQD2/2)
• Dmax to thecal sack
• LARGE confidence intervals
ESTRO SBRT 2017 - Matthias Guckenberger
16
07.09.17