Gliomas de tallo cerebral; generalidades de diagnóstico, tratamiento y pronóstico

Abstract

Brainstem gliomas are uncommon, in adults they account for 1-2% of intracranial gliomas. In adults, a low-grade phenotype predominates, a feature that probably accounts for its better prognosis compared to children. Because biopsy is performed infrequently, a classification based on radiological aspects in MRI has been proposed to establish treatment strategies and determine the outcome: 1. Intrinsic diffuse “low-grade”. 2. Brainstem glioma “malignant” with focal reinforcement. 3. Exophytic. 4. Focal tectal gliomas. Despite important advances in neuroradiology such as multivoxel magnetic resonance spectroscopy, diffusion tensor and perfusion, a pure radiological classification remains imperfect in the absence of a histological diagnosis. While biopsy can be reasonably avoided in diffuse forms, a histological test is required in many brainstem lesions when contrast-enhancing lesions are evident because of the wide variety of differential diagnoses in adults. Radiation therapy is the standard treatment for intrinsic diffuse brainstem gliomas “low-grade” in adults (mean survival rate is 5 years). In malignant stem gliomas with focal reinforcement, radiation therapy is the standard treatment and the possible benefit of radiotherapy and combination chemotherapy (temozolamide or other agents) has not been thoroughly evaluated in adults. The role of anti-angiogenic therapies in brainstem gliomas remains to be defined. A better understanding of the biology of these tumors is of great importance in order to identify homogeneous subgroups and improve therapy.