Classification of unilateral thalamic gliomas predicts tumor resection and patient's survival: a single center retrospective study.

Background: The aim of this study was to propose our classification about unilateral thalamic gliomas, and to describe relationship between the classification and clinical characteristics including symptoms, surgical approaches and survival, which should contribute to the treatment and the prognostic prediction of unilateral thalamic gliomas.

Methods: A total of 66 adult unilateral thalamic glioma patients with pathologic confirmation between January 2010 and December 2018 were retrospectively investigated.

Results: Unilateral thalamic gliomas could be divided into quadrigeminal cistern and ventricle extension type (type Q), lateral type (type L) and anterior type (type A) according to tumor location, extensive polarity and location of ipsilateral posterior limb of internal capsule. Each subtype of QLA classification could match with one kind of corresponding approach. Preoperative symptoms including headache, dyskinesia, aphasia, hydrocephalus and KPS scores, and pathological features including H3K27M mutation and P53 expression were correlated with QLA classification. Further analysis confirmed that type Q tumors had a higher rate of total resection and a significantly longer survival time compared to type L and type A tumors, with similar improved and deteriorated rates of symptoms. Univariate and multivariate analysis demonstrated QLA classification was remarkedly associated with overall survival and could be considered as an independent prognostic factor in patients with unilateral thalamic gliomas.

Conclusions: Unilateral thalamic glioma could be divided into 3 subtypes by imaging characteristics, symptoms and survival. QLA classification could predict tumor resection and the prognosis and could contribute to the planning of therapeutic strategy in patients with unilateral thalamic gliomas.