Radiohistogenomics of pediatric low-grade neuroepithelial tumors

Abstract

Purpose In addition to histology, genetic alteration is now required to classify many central nervous system (CNS) tumors according to the most recent World Health Organization CNS tumor classification scheme. Although that is still not the case for classifying pediatric low-grade neuroepithelial tumors (PLGNTs), genetic and molecular features are increasingly being used for making treatment decisions. This approach has become a standard clinical practice in many specialized pediatric cancer centers and will likely be more widely practiced in the near future. This paradigm shift in the management of PLGNTs necessitates better understanding of how genetic alterations influence histology and imaging characteristics of individual PLGNT phenotypes. Methods The complex association of genetic alterations with histology, clinical, and imaging of each phenotype of the extremely heterogeneous PLGNT family has been addressed in a holistic approach in this up-to-date review article. A new imaging stratification scheme has been proposed based on tumor morphology, location, histology, and genetics. Imaging characteristics of each PLGNT entity are also depicted in light of histology and genetics. Conclusion This article reviews the association of specific genetic alteration with location, histology, imaging, and prognosis of a specific tumor of the PLGNT family and how that information can be used for better imaging of these tumors.

Advanced Neuroimaging Approaches to Pediatric Brain Tumors

“…Interestingly, recent studies have discovered some overlap in molecular profiling between LGG and HGG, and BRAF V600E and FGFR1 mutations can be found both in LGG and HGG [ 32 , 36 ], suggesting that LGG and HGG might share a similar biological mechanism of tumor pathogenesis. While LGGs are heterogenous, the spatial clustering of individual tumor phenotypes and the spatial enrichment of specific genetic mutations highlight the importance and potential of the radiohistogenomic profiling of LGGs [ 38 ].…”

Updates on management of gliomas in the molecular age

“…Chemotherapy was first introduced in the 1980s to avoid or delay pediatric exposure to therapeutic doses of radiation. The first line treatment in Europe and the United States for pLGG remains a combination of vincristine and carboplatin (V/C) as standard induction[ 58 - 62 ]. The standard dosage of V/C may vary considering characteristics of the patient, tumor, and specific protocol.…”

The 2021 WHO Classification for Gliomas and Implications on Imaging Diagnosis: Part 3—Summary of Imaging Findings on Glioneuronal and Neuronal Tumors

“…First, similarly to pediatric-type diffuse low-grade gliomas, mitogen-activated protein kinase (MAPK) pathway alteration is the major genetic event driving the tumorigenesis in these tumors. [28][29][30] The upregulation of MAPK pathway alteration results in increased cell growth and differentiation. 31 Within MAPK pathway alteration, BRAF mutation (BRAF p. V600E, in which a valine is replaced with a glutamic acid at position 600), BRAF oncogenic fusion such as KIAA1549::BRAF, and FGFR alterations are the most common pathway alterations in these tumors.…”