Stereotactic Brain Biopsy

A stereotactic brain biopsy is a minimally invasive procedure used to obtain a small tissue sample from an area of the brain, in order to reach a precise diagnosis. Rather than removing the entire area of concern, as in open surgery, a fine needle is guided to the target using stereotactic imaging and planning; the same general approach to precise, image-guided targeting used elsewhere in functional neurosurgery, through a small opening in the skull.

Biopsy is generally considered when the nature of a finding on brain imaging is unclear, when a confirmed diagnosis is needed to guide treatment (for example, deciding between chemotherapy, radiation or other medical treatment), when the lesion lies in a deep or high-risk location where full removal would carry substantial risk, or when there is a reasonable possibility of a diagnosis (such as certain lymphomas or inflammatory and infectious conditions) that is treated with medication rather than open surgical removal.

Stereotactic biopsy is generally considered for patients with a brain lesion of uncertain nature on imaging where a tissue diagnosis would change or guide treatment, particularly when the lesion is not a good candidate for, or does not require, open surgical removal.

A biopsy is typically considered once imaging alone cannot confirm the diagnosis with confidence, and a multidisciplinary team (which may include neurosurgery, neurology, oncology or infectious disease specialists depending on the suspected cause) agrees that tissue diagnosis is needed to plan appropriate treatment.

The procedure is generally performed under sedation or general anesthesia. Using stereotactic planning based on the patient’s imaging, a small opening (burr hole) is made in the skull, and a fine biopsy needle is advanced along the planned trajectory to the target. The trajectory can be held using a traditional stereotactic frame, a frameless navigation system, or a surgical robot; all are ways of achieving the same precise, planned path to the target, and which is used depends on the equipment available and the surgical team’s approach. Small tissue samples are taken, and in many centers a pathologist reviews an initial sample during the procedure to help confirm that the tissue obtained is adequate for diagnosis before the procedure is completed.

• Detailed review of prior imaging and, where relevant, other test results
• Assessment of the safest available trajectory to the target
• General health assessment for a procedure performed under sedation or anesthesia
• Multidisciplinary discussion of what diagnoses are most likely and how the result will guide treatment

The goal of stereotactic biopsy is a confident tissue diagnosis obtained with a smaller, lower-risk procedure than open surgery, allowing the right treatment to be planned. It is a diagnostic procedure rather than a treatment for the underlying condition itself; further treatment depends on what the biopsy shows.

The main risks are bleeding at the biopsy site (the most significant risk, given that the needle passes through brain tissue to reach the target) and infection; seizures can occasionally occur. Because only a small sample of tissue is taken, there is a possibility that the result is inconclusive or non-diagnostic, which occasionally means a repeat biopsy or a different diagnostic approach is needed.

Most patients are observed in hospital overnight, with imaging typically performed after the procedure to check for bleeding before discharge. Recovery from the biopsy procedure itself is generally quick; what happens next depends entirely on the diagnosis and is planned with the relevant specialist team.