[Frameless stereotactic biopsy: diagnostic yield and complications]

Use of 5-Aminolevulinic Acid for Confirmation of Lesional Biopsy Sample in Presumed High-Grade Glioma

BACKGROUND

5-amniolevulinic acid (5-ALA) assists neurosurgeons in defining operative margins during resection of high-grade gliomas, leading to improved rates of complete resection of enhancing tumor and progression-free survival. Here, we propose the use of 5-ALA in stereotactic biopsy for confirmation that the sample obtained is from the targeted mass. To the knowledge of the authors, this is the first known record of 5-ALA use for confirmation of pathologic specimen in stereotactic brain biopsy in the United States. This technique could be pivotal for lesions in highly eloquent areas where it is important to take as little tissue as possible in an effort to decrease neurologic deficits while still obtaining a diagnostic biopsy sample.

CASE DESCRIPTION

The patient is a 67-year-old male who initially presented with computed tomography and magnetic resonance imaging concerning for a high-grade glioma in the right basal ganglia and deep white matter of the frontal lobe. Final pathology concluded that specimens obtained during biopsy were indeed pathologic at the periphery of the lesion, and there was necrotic tissue at the center of the lesion. Fluorescence of biopsy samples was 100% concordant with pathologic analysis.

CONCLUSIONS

5-ALA may prove a useful tool for intraoperative confirmation of pathologic tissue, especially in areas of high eloquence, where small biopsy sizes are essential. It may also obviate the need for an intraoperative consultation to a pathologist. However, additional studies with larger study populations are warranted.

Tubular brain tumor biopsy improves diagnostic yield for subcortical lesions

PURPOSE

Molecular data has become an essential part of the updated World Health Organization (WHO) grading of central nervous system tumors. However, stereotactic needle biopsies provide only small volume specimens and limit the extent of histologic and molecular testing that can be performed. We assessed the use of a tubular retractor-based minimally invasive biopsy technique to provide improved tissue yield and diagnostic data compared to needle biopsy.

METHODS

Eighteen patients underwent an open transtubular biopsy compared to 146 stereotactic biopsies during the years of 2010-2018.

RESULTS

Tubular biopsies resulted in a higher volume of tissue provided to the pathologist than needle biopsies (1.26 cm³ vs. 0.3 cm³; p < 0.0001). There was a higher rate of non-diagnostic sample with stereotactic compared to transtubular biopsy (13% vs. 0%; p = 0.13). Six patients who underwent stereotactic biopsy required reoperation for diagnosis, while no transtubular biopsy patient required reoperation in order to obtain a diagnostic specimen. Postoperative hematoma was the most common post-operative complication in both groups.

CONCLUSIONS

Stereotactic transtubular biopsies are a viable alternative to stereotactic needle biopsies with excellent rates of diagnostic success and acceptable morbidity relative to the needle biopsy technique. As molecular data begins to increasingly drive treatment decisions, additional biopsy techniques that afford large tissue volumes may be necessary to adapt to the new needs of pathologists and treating oncologists.