Brain metastases
Last edit by Alaric Steinmetz on
Synonyms: Brain metastasis
Brain metastases are space-occupying lesions in the brain that originate from a primary tumor located outside the brain. Depending on their number, size, and clinical symptoms, surgical removal may be indicated. In principle, brain metastases can occur anywhere in the brain.
Epidemiology
In adults, brain metastases are the most common tumors in the brain and occur annually in 10–15 per 100 000 persons; in 30–50 % of cases, they are solitary metastases[^2].
Primary tumors
Lung carcinomas, renal cell carcinomas, and colorectal carcinomas account for approximately 80% of brain metastases in men, whereas in women, breast carcinomas, lung carcinomas, colorectal carcinomas, and melanomas are responsible for 80% of metastases[^3].
The risk of developing a brain metastasis varies depending on the primary tumor[^1]:
Primary tumor | Estimated cumulative incidence after 5 years |
Lung carcinoma | 16,3 % |
Renal cell carcinoma | 9,8 % |
Melanoma | 7,4 % |
Breast carcinoma | 5 % |
Colorectal carcinoma | 1,2 % |
Imaging
The gold standard for imaging brain metastases is MRI imaging. In brain metastases involving the bone, additional CT imaging may be helpful.
Radiosensitivity
Depending on the primary tumor, brain metastases show varying degrees of response to radiation therapy. The following table shows the radiosensitivity of various brain metastases to Whole-brain radiation therapy[^4] [^5]:
Radiosensitivity | Tumor |
Radiosensitive |
|
Moderately sensitive |
|
Moderately resistant |
|
Highly resistant |
|