Reassessing the Role of Brain Tumor Biopsy in the Era of Advanced Surgical, Molecular, and Imaging Techniques-A Single-Center Experience with Long-Term Follow-Up

Abstract

Brain biopsy is the gold standard in order to establish the diagnosis of unresectable brain tumors. Few studies have investigated the long-term outcomes of biopsy patients. The aim of this single-institution-based study was to assess the concordance between radiological and histopathological diagnoses, and the long-term patient outcome. Ninety-three patients who underwent brain biopsy in the last 5 years were analyzed. We included patients treated with stereotactically guided needle, open, and neuroendoscopic biopsies. Most patients (86%) received needle biopsy. Gliomas and primary brain lymphomas comprised 88.2% of cases. The diagnostic yield was 95.7%. Serious complication and death rates were 3.2% and 2.1%, respectively. The concordance rate between radiological and histological diagnoses was 93%. Notably, the positive predictive value of radiological diagnosis of lymphoma was 100%. Biopsy allowed specific treatment in 72% of cases. Disease-related neurological worsening was the main reason that precluded adjuvant treatment. Adjuvant treatment, in turn, was the strongest prognostic factor, since the median overall survival was 11 months with vs. 2 months without treatment (p = 0.0002). Finally, advanced molecular evaluations can be obtained on glioma biopsy specimens to provide integrated diagnoses and individually tailored treatments. We conclude that, despite the huge advances in imaging techniques, biopsy is required when an adjuvant treatment is recommended, particularly in gliomas.

Keywords: biopsy; follow-up; high-grade glioma; primary brain lymphoma; radiology.

Figure 1

Neuroradiological and histological features of PCNSL. (A) Axial T2-weighted and (B) axial Gd-enhanced T1-weighted MR imaging showing a T2 hypointense mass involving splenium of the corpus callosum, without necrosis, and with vivid contrast enhancement. DWI (C) showing restricted diffusion and SWI (D) showing absence of intratumoral hemorrhage. Arrows point at the tumor (A–E). CBV map (E) shows moderately increased intratumoral rCBV. The neuropathological examination reveals a high-grade diffuse B cell non-Hodgkin lymphoma (F) showing strong CD20 positivity (F, inset).

Figure 2

Neuroradiological and histological features of HGG. Axial T2-weighted (A) and axial Gd-enhanced T1-weighted (B) MR imaging showing a heterogeneous mass in the left insula and basal ganglia, with irregular ring enhancement, corresponding to areas of restricted diffusion on DWI (C) and elevated perfusion on CBV map (D). SWI (E) shows extensive “blooming” foci, consistent with intratumoral hemorrhage. Arrows point at the tumor (A–E). MRS (F) shows elevated Cho and decreased NAA. MRI features are consistent with GBM. The neuropathological examination confirms the presence of a high-grade diffuse astrocytic glioma (G) with evidence of vascular proliferation (not shown). The tumor is IDH-wt and shows strong immunoreactivity for GFAP (G, inset).