Stereotactic biopsies of brainstem lesions: dilemma on the best trajectory

Roles and outcomes of stereotactic biopsy for adult patients with brainstem lesion

PURPOSE

This study aimed to assess the benefit-risk ratio by determining diagnostic yield and safety of brainstem biopsies in adult patients. The secondary objectives were (i) to compare brainstem biopsy safety and postbiopsy patients' outcomes and survival with those of patients biopsied for a brain or cerebellar lesion, and (ii) to assess the impact of brainstem biopsy on final diagnosis and further therapeutic management.

METHODS

Among 1784 stereotactic biopsies performed in adult patients at a tertiary center between April 2009 and October 2020, we retrospectively examined 50 consecutive brainstem biopsies. We compared variables regarding diagnostic yield, safety and post-biopsy outcomes between brainstem biopsy patients and brain/cerebellum biopsy patients.

RESULTS

Brainstem biopsy led to a diagnosis in 86% of patients (94.6% in patients with suspected tumor). Lesion contrast enhancement on imaging was the sole predictor of obtaining a diagnosis. Rates of symptomatic complications and mortality were significantly higher in brainstem biopsy patients compared to brain/cerebellum biopsy patients (20% vs 0%; p < 0.001 and 6% vs 0%; p = 0.01, respectively). Transfrontal trajectory and prebiopsy swallowing disorders were predictors of brainstem biopsy-related symptomatic complications. Brainstem biopsy findings led to diagnostic change in 22% of patients.

CONCLUSIONS

Stereotactic biopsy in adult patients with brainstem lesion has a high diagnostic yield. Although stereotactic brainstem biopsy is associated with more functional and fatal complications than biopsies targeting the brain/cerebellum, its safety profile appears acceptable. Thus, the benefit-risk ratio of stereotactic biopsy in patients with brainstem lesion is favorable but should nevertheless be carefully weighted on a case-by-case basis.

Adult brainstem glioma differential diagnoses: an MRI-based approach in a series of 68 patients

BACKGROUND

Brainstem gliomas are rare in adults. The diagnosis is often difficult, as some teams still consider brainstem biopsies dangerous and often avoid this procedure. The aim of this study was to describe differential diagnoses that can mimic brainstem glioma, to help clinicians avoid diagnostic and therapeutic mistakes, and to propose a diagnostic algorithm according to radiological presentations.

METHODS

The French network of adult brainstem gliomas (GLITRAD) retrospectively collected all reported cases of differential diagnoses between 2006 and 2017. The inclusion criteria were as follows: age over 18 years, lesion epicenter in the brainstem, radiological pattern suggestive of a glioma and diagnostic confirmation (histopathological or not, depending on the disease).

RESULTS

We identified a total of 68 cases. Most cases (58/68, 85%) presented as contrast-enhancing lesions. The most frequent final diagnosis in this group was metastases in 24/58 (41%), followed by central nervous system lymphoma in 8/58 (14%). Conversely, MRI findings revealed 10/68 nonenhancing lesions. The most frequent diagnosis in this group was demyelinating disease (3/10, 30%).

CONCLUSION

The risk of diagnostic mistakes illustrates the need to consider the more systematic use of a brainstem biopsy when reasonably possible. However, we propose an MRI-based approach to the differential diagnosis of gliomas to limit the risk of misdiagnosis in cases where a biopsy is not a reasonable option.

Stereotactic Biopsy for Brainstem Lesions: A Meta-analysis with Noncomparative Binary Data

Objectives

To evaluate the diagnostic yield and safety of brainstem stereotactic biopsy for brainstem lesions.

Methods

We performed a meta-analysis of English articles retrieved from the PubMed, Web of Science, Cochrane Library, and APA psycInfo databases up to May 12, 2021. A binary fixed-effect model, the inverse variance method, or a binary random-effect model, the Dersimonian Laird method, were utilized for pooling the data. This meta-analysis was registered with INPLASY, INPLASY202190034.

Findings

A total of 41 eligible studies with 2792 participants were included. The weighted average diagnostic yield was 97.0% (95% confidential interval [CI], 96.0-97.9%). The weighted average proportions of temporary complications, permanent deficits, and deaths were 6.2% (95% CI, 4.5–7.9%), .5% (95% CI, .2–.8%), and .3% (95% CI, .1–.5%), respectively. The subgroup analysis indicated a nearly identical weighted average diagnostic yield between MRI-guided stereotactic biopsy and CT-guided stereotactic biopsy (95.9% vs 95.8%) but slightly increased proportions of temporary complications (7.9% vs 6.0%), permanent deficits (1.9% vs .2%), and deaths (1.1% vs .4%) in the former compared to the latter. Moreover, a greater weighted average diagnostic yield (99.2% vs 97.6%) and lower proportions of temporary complications (5.1% vs 6.8%) and deaths (.7% vs 1.5%) were shown in the pediatric patient population than in the adult patient population.

Conclusions

Brainstem stereotactic biopsy demonstrates striking accuracy plus satisfying safety in the diagnosis of brainstem lesions. The diagnostic yield, morbidity, and mortality mildly vary based on the diversity of assistant techniques and subject populations.