Surgical waste from stereotactic glioma biopsies contains clinically relevant tumor DNA

Abstract

Stereotactic needle biopsy is an established approach for sampling gliomas in deep, midline, or eloquent brain regions, but tissue acquisition remains constrained by the need to preserve material for histopathology, molecular testing, and research. During routine specimen handling, needle rinse fluid, expelled aspiration material, and gauze-associated debris are discarded as waste. This waste could contain diagnostically relevant tumor material. To evaluate this hypothesis, we collected 32 waste samples from 31 stereotactic needle biopsy procedures and evaluated whether they contained recoverable tumor-derived DNA. Among 28 samples with a clinically identified, testable tumor-associated alteration available for comparison, one failed targeted amplification after low DNA recovery. Review guided by clinical findings detected at least one corresponding alteration in all successfully sequenced samples (27/27), yielding an overall detection rate of 96% (27/28). In paired clinical and waste TSO500 analyses, waste sequencing identified all eligible reported variants in 12 of 15 samples. Waste sequencing also identified relevant mutations that matched marker-positive IHC findings, providing sequence-level context for IDH1 , ATRX , and TP53 alterations. These findings show that material routinely discarded during stereotactic needle biopsy can be a recoverable source of tumor-derived DNA for research, retrospective molecular analysis, and ancillary profiling when tissue is limited or unavailable.