Metastatic Brain Tumors: Introduction

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.