This document discusses brain metastases, which occur when cancer originating elsewhere in the body spreads to the brain. It outlines the most common primary cancers that lead to brain metastases, including lung cancer in 50% of cases. Symptoms, diagnostic imaging, and treatment options like whole brain radiation, radiosurgery, and surgery are described. Whole brain radiation provides initial tumor response in 70-90% of cases and functional improvement in 50-60% of patients. However, long term side effects can include white matter changes. Prognosis depends on performance status and extent of disease, with median survival ranging from 2-14 months depending on these factors.

1. Brain Metastases
Robert Miller MD
www.aboutcancer.com
 Brain metastases or primary
brain tumors (glioma)
 Treatment options
 Side effects of treatment

2. Brain metastases: cancer
that started elsewhere in the
body (e.g. lung or breast)
and spread to the brain
Brain primary: a normal
brain cell (glial cell)
becomes malignant and is
called a glioma

3. Brain Metastases
 Most common intracranial tumors in
adults
 In patients with stage IV disease , 10 –
30% will have brain mets

4. The odds of developing brain metastases
based on the primary type of cancer
 Lung: 16 to 20%
 Melanoma: 7%
 Kidney: 7 to 10%
 Breast: 5%
 Colorectal: 1 to 2%

5. The most common causes of brain metastases in adults
with their approximate frequency are:
Lung — 50 percent
Breast — 15 to 20 percent
Unknown primary 10 percent
Melanoma — 10 percent
Colon and rectum 5 percent
The distribution of metastases roughly follows the relative
weight of and blood flow to each area.
Cerebral hemispheres — 80 percent
Cerebellum — 15 percent
Brain stem — 5 percent

6. SYMPTOMS OF BRAIN METASTASES
Symptom Patients %
Headache 42
Focal weakness 27
Mental change 31
Seizure 20
Gait ataxia 17
Sensory disturbance 6
Speech problems 10

7. Note that tumors may cause symptoms on
the opposite side of the body

8. Brain Swelling – brain tumor often cause swelling or
edema which creates pressure on the brain, with headaches
and nausea, steroids like Decadron (dexamethasone) will
decrease this pressure

9. Brain Imaging

10. Glioblastoma
Certain brain
tumors .e.g.
glioma have a
distinct
appearance on
MRI scan . With
irregular borders
and necrotic
center

11. Glioblastoma
cells in green,
spread diffusely
through the brain
and are hard to
target accurately

12. Brain Metastasis as seen on an MRI Scan, the
sharp margins may make this a better case for
highly targeted radiation

13. Normally the radiologist can tell the difference
between a brain tumor and a stroke (if not
sometimes a biopsy is necessary)

14. Other Brain Tumors that are NOT cancer
Both of these are examples of a brain abscess

15. Multiple Brain Metastases
MRI suggests that in 66 to 75% of the cases,
there are multiple metastases
Metastases from breast, colon, and renal cell
carcinoma are more often single,
while lung cancer and malignant melanoma
have a greater tendency to produce multiple
metastases

16. Brain Metastases are usually Multiple
(66 – 75% of the cases)

17. Brain Metastases are Usually Multiple

18. PET Scans and the Brain
Because a PET measures uptake of glucose and the brain uses a lot of
glucose, the normal brain looks very active on a PET scan

19. PET Scans and the Brain
PET scan showed an abnormal area in the left frontal lobe and MRI
confirmed this as a brain metastasis from breast cancer

20. Brain Radiation
Depending on the type and number of brain
tumors, the patient may receive radiation to
the whole brain, or partial brain or have
highly targeted radiation (called radiosurgery,
e.g. Cyberknife or gamma knife)

21. www.nccn.org

25. Whole brain irradiation

26. Whole brain radiation

27. The response or benefit
from whole brain radiation
may take several weeks to
months

28. Typical Response to Whole Brain Radiation

29. The small
lesion is no
longer
visible and
the large
lesion is
much
smaller

31. Typical response for whole brain radiation

32. Typical response for whole brain radiation,
small cell lung cancer

33. Typical response for whole brain radiation

34. Radio resistant cancer (renal cell) MRI appearance two months after
whole brain radiation (small lesions gone and large lesion much
smaller)

35. Radiosurgery for Cancer

37. Typical time
interval to
regression after
radiosurgery
Cyberknife or
Gamma Knife)

38. For a single lesion, radiosurgery alone may be used,
but there is a higher risk of a new lesion showing up in
the brain
Jan 2011 - Radiosurgery Aug 2012 – Treated tumor is virtually gone, but
there is a new tumor on the opposite side of the
brain

39. Radiation Doses
 Whole brain: 20 – 40 Gy in 5 to 20
fractions
 Radiosurgery: 15Gy (3.1 – 4cm), 18Gy
(2.1 to 3cm) or 24Gy (2cm or less)

40. How often does whole brain radiation
help?
• 70 -90% initial response
• > 50% of symptoms of headache, CSF pressure have
complete response
• 50 -60% have functional improvement
moderate dysfunction: 1/3 near normal at median
time of 3 weeks
severe dysfunction: 2/3 improve at median of 1-2
weeks

41. Side Effects of Whole Brain
Radiation
1. Hair loss (usually takes two or three weeks to happen)
2. Mild skin itching or irritation
3. Short term more fatigue or slightly more confusion or
memory problems
4. Mild headache or nausea is uncommon but may require
medication (Decadron)
5. Occasionally hearing problems (fluid behind the ear
drums)

42. Long Term Effects of Radiation on the Brain
This patient had no symptoms, but radiation may effect
memory

43. Long Term Effects of Radiation on the Brain
This patient had no symptoms

44. Long Term Effects of Radiation on the Brain
This patient had no symptoms

45. Long Term Effects of Radiation on the Brain
This patient had no symptoms

46. Risk of white matter changes (leukoencephalopathy) 1
year after whole brain radiation for brain mets
U Pitt Study E Monaco (AANS 2012, Medscape Med News 2012-05-01)
WB+SRS SRS
1 year 97.3% 3.2%
So by one year 97% has some changes and
by 2 years 70% had grade 3 changes on the
MRI (but no symptoms)

47. Radiosurgery for Brain
Metastasis
 Local control Rates of 73 to 94%
 Risk of radiation necrosis of 5 to 10%
Better than whole brain if single lesion and good performance patient in the
RTOG 95-08 Trial

48. Complications of Radiosurgery
 Short term side effects are uncommon
(2%) with worsening symptoms or new
seizures
 About one third mild swelling
(headaches, nausea)
 Radionecrosis in 5% to 10%

49. Sometimes the MRI
will look worse after
radiosurgery due to
radionecrosis of the
cancer but with time
this should fade away

50. Survival and Prognosis for
People with Brain Metastases
1. Do best if the cancer is confined to the brain only
2. Do better if they are young (< 65y)
3. Do better if they have a good performance score (i.e. a
high Karnofsky score of 70 or better)
Karnofsky Score (KPS) 70 = Cares for self; unable to carry on normal
activity or do active work
KPS 60 = Requires occasional assistance, but is able to care for most
personal needs

51. Median Survival Based on RTOG Class for
People with Brain Metastases
 I (KPS =70, age < 65y, mets to brain only) = 7.1 to
10.5 months
 II KPS = 70 = 3.5 to 4.2 months
 III KPS < 70 = 2.0 to 2.3 months
Karnofsky Score (KPS) 70 = Cares for self; unable to carry on normal
activity or do active work
KPS 60 = Requires occasional assistance, but is able to care for most
personal needs

52. Survival by Treatment (WB whole brain, S
surgery, RS radiosurgery) and Performance
Score (RTOG)
RTOG WB S RS
I 7.1 mos 14.8 mos 16.1 mos
II 4.2 mos 9.9 mos 10.3 mos
III 2.3 mos 6.0 mos 8.9 mos

53. Brain Metastases
Robert Miller MD
www.aboutcancer.com