Brain Mets

Question 1

CNS: constraints: Optic chiasm - SRS (1fx) max point

Answer 1

8 gy

Question 2

CNS: constraints: Brain stem - SRS (1fx) max point

Answer 2

12 Gy

Question 3

CNS: constraints: Optic nerve - SRS (1fx) max point

Answer 3

8 Gy

Question 4

Brain met: differential for brain lesion DR MAGIC L

Answer 4

demyelinating disease
radiation necrosis or resolving hematoma
metastasis
abscess
GBM
infarct
contusion
lymphoma

Question 5

Brain met: Work up

Answer 5

H&P with attention to smoking history, neuro, skin, breast and pelvic exam
MRI w/ and w/o
CT pan scan +/- mammogram

Question 6

Brain met: dex dosing

Answer 6

10 mg load, 4 mg q6hours

Question 7

Brain met: Median survival untreated

Answer 7

4 weeks

Question 8

Brain met: RT dose, single fx SRS intact met

Answer 8

< 2cm - 24 Gy
2-3 cm - 18 Gy
> 3 cm - 15 Gy

Question 9

Brain met: RT dose, fractionated fx SRS to cavity post-op

Answer 9

27 Gy in 3 fx
30 Gy in 5 fx

Question 10

Brain met: HA-WBRT constraints
Hippocampi D100% and max
Whole brain D2% (max)
Optic structures max

Answer 10

Hippocampi: D100% (min dose) < 9 Gy, Max < 16 Gy
Whole brain: D2% < 37.5 Gy
Optic structures: Max < 30 Gy

Question 11

5 fx Brain SRS constraints: Brain stem max

Answer 11

30 Gy

Question 12

5 fx Brain SRS constraints: Cochlea max

Answer 12

25 Gy

Question 13

5 fx Brain SRS constraints: Optic structures max

Answer 13

25 Gy

Question 14

5 fx Brain SRS constraints: Spinal cord D0.035

Answer 14

28 Gy

Question 15

5 fx Brain SRS constraints: Brain minus GTV V20Gy

Answer 15

20-23 cc