Precautions to Improve the Accuracy of Stereotactic Biopsy for Brain Malignancies

Stereotactic biopsy is necessary for diagnosing deep-seated brain tumors that are not amenable to surgical resection. The diagnostic yield of stereotaxy ranges from 76.2 to 100%. Several methods have been suggested to improve the yield. These include planning the trajectory on 3D multiplanar reconstruction (3D MPR) software, planning two different trajectories for different target points, centering the burr hole at the entry point, taking at least six specimens from each target, macroscopic assessment of the biopsy bits, and postbiopsy scan. We implemented similar precautions to ensure the diagnostic yield. Three cases were analyzed retrospectively and descriptively. The contrast-enhanced magnetic resonance imaging (CEMRI) of the first patient showed a high-grade neoplasm of the left corona radiata and corpus callosum. Craniostomy and stereotactic biopsy were done. Computed tomography (CT) showed the tract as dots of bleed into the lesion. The histopathological report (HPR) was of anaplastic astrocytoma. The second case was peculiar in the presentation as bilateral high-grade glioma. The CT imaging after stereotaxy showed air within the lesion, confirming the site. The immunohistochemistry (IHC) was suggestive of grade 3 astrocytoma. The third case was a diagnostic dilemma, with incomplete ring enhancement on CEMRI. Postoperative CT confirmed the site of biopsy as a cut. The IHC proved diagnosis of diffuse large B cell lymphoma. Placing the stereotactic ring around the lesion, making a craniostomy of size 3 cm, doing surgery under general anesthesia, biopsy from multiple targets, harvesting more than six specimens, and immediate postoperative CT helped in ensuring the accuracy of biopsy.