Rachinger, Walter; Grau, S.; Holtmannspötter, Markus; Herms, Jochen; Tonn, Jörg-Christian; Kreth, Friedrich-Wilheln
Serial stereotactic biopsy of brainstem lesions in adults improves diagnostic accuracy compared with MRI only.
In: Journal of Neurology, Neurosurgery and Psychiatry, Vol. 80: pp. 1134-1139
Objective: The aim of the current prospective study was
to analyse the validity of MRI based diagnosis of
brainstem gliomas which was verified by stereotactic
biopsy and follow-up evaluation as well as to assess
prognostic factors and risk profile.
Methods: Between 1998 and 2007, all consecutive adult
patients with radiologically suspected brainstem glioma
were included. The MRI based diagnosis of the lesions
was made independently by an experienced neuroradiologist.
Histopathological evaluation was performed in all
patients from paraffin embedded specimens obtained by
multimodal image guided stereotactic serial biopsy
technique. Histopathological results were compared with
prior radiological assessment. Length of survival was
estimated with the Kaplan–Meier method and prognostic
factors were calculated using the Cox model.
Results: 46 adult patients were included. Histological
evaluation revealed pilocytic astrocytoma (n=2), WHO
grade II glioma (n=14), malignant glioma (n=12),
metastasis (n=7), lymphoma (n=5), cavernoma
(n=1), inflammatory disease (n=2) or no tumour/
gliosis (n=3). Perioperative morbidity was 2.5% (n=1).
There was no permanent morbidity and no mortality. All
patients with ‘‘no tumour’’ or ‘‘inflammatory disease’’
survived. Patients with low grade glioma and malignant
glioma showed a 1 year survival rate of 75% and 25%,
respectively; the 1 year survival rate for patients with
lymphoma or metastasis was 30%. In the subgroup with a
verified brainstem glioma, negative predictors for length of
survival were higher tumour grade (p=0.002) and
Karnofsky performance score (70 (p=0.004).
Conclusion: Intra-axial brainstem lesions with a radiological
pattern of glioma represent a very heterogeneous
tumour group with completely different outcomes.
Radiological features alone are not reliable for diagnostic
classification. Stereotactic biopsy is a safe method to
obtain a valid tissue diagnosis, which is indispensible for