00:01
So how do we think about
brain metastases?
What are the common tumors that
travel and metastasize to the brain?
Well, lung cancer is common.
00:09
A lot of people get lung cancer
and so lung cancer
can metastasize to the brain
and it should be something
that we consider.
00:16
Breast cancer, this is the same.
It's a common cancer,
it's a common tumor,
and patients can live a long time
from systemic therapy
long enough for tumors
to metastasize to the brain.
00:26
Melanoma is not as common.
It's a less common cancer,
but it has a predilection
for the brain.
00:31
It likes to go to the brain.
00:33
Melanoma cells.
00:34
Melanocytes arise
from neural crest cells,
which are a nerve tissue of origin,
and this may allow us to understand
some of melanomas predilection
for the brain.
00:45
Renal cell carcinomas
can go and travel to the brain
and can bleed they're an
important tumor to consider,
and colorectal cancer.
00:52
So that takes us from the common
to the less common tumors
that like to metastasize
to the brain.
00:57
Will remember in terms of
primary brain tumors,
we also consider them in terms of
how common they are.
01:01
Meningiomas
are the most common,
followed by gliomas,
and pituitary adenomas,
and vestibular schwannomas.
01:09
How do patients with
brain metastases present?
Well, commonly, we see
new focal neurologic deficits
or seizures.
01:17
And that tells us that there is a
part of the brain, the focus,
where there is a problem.
01:21
And we should image it
with a CT or an MRI.
01:24
Headache is common.
01:25
It's seen in a quarter
to a half of patients,
but many things cause headache.
01:29
And so we're really looking
for headache in the setting
of nausea, vomiting, or
that focal neurologic deficit.
01:37
What do we do?
A patient who has a systemic cancer,
a lung cancer,
a breast cancer, or a melanoma,
and presents with a
new focal neurologic deficit
should undergo imaging.
01:47
CT is good for evaluating
hemorrhage.
01:50
And MRI is really superior
for looking at lesions
that occur in the brain.
01:55
Where do we see brain metastases
on imaging?
Well, the most common places
the hemisphere.
02:00
And you see here
80% of brain metastases
are seen in the hemispheres.
02:05
The lesions highlighted
in green here
are at the gray-white junction,
that border between
the cortical gray matter
and the subcortical white matter
where there are
large blood vessels for cancers
to hematogenously spread.
02:19
We also see brain metastases
in the cerebellum,
and occasionally in the brainstem.
02:25
They classically appear
at the gray-white junction,
a very important imaging signature
for brain metastases.
02:34
Which cancer patients or
which type of cancer patients
should undergo evaluation
with MRI for brain metastasis?
Well, there's three groups that
I would like for you to think of.
02:45
The first group are patients
where MRI is recommended
at the time of diagnosis
because they're at such
high likelihood
of developing brain metastasis.
02:54
And that includes
small cell lung cancer,
some non-small cell lung cancers,
and advanced melanoma.
03:00
And this gets back to both
small cell lung cancer
and melanomas predilection
to travel to the brain.
03:06
In fact,
in some of those patients,
we prophylactically treat the brain
to prevent those tumors
from developing.
03:12
The second group are patients
where MRI is recommended
if the patient develops
a focal neurologic deficit.
03:19
And this includes breast cancer,
renal cell carcinoma,
and colorectal cancer.
03:23
Cancers that we know
can metastasize to the brain,
but not as commonly
as that first group.
03:29
The last group are cancers
where we uncommonly see
brain metastasis,
and this includes squamous
cell carcinoma of the head, neck,
pancreatic cancer,
and prostate cancer.
03:38
So the patient's type of cancer
can help guide us in terms to our
level of suspicion
for a brain metastasis.