<scp>cIMPACT</scp> ‐ <scp>NOW</scp> update 11: Proposal on adaptation of diagnostic criteria for <scp>IDH</scp> ‐ and <scp>H3</scp> ‐wildtype diffuse high‐grade gliomas and for posterior fossa ependymal tumors
Bibliographic record
Abstract
The Consortium to Inform Molecular and Practical Approaches to Central Nervous System Tumor Taxonomy (cIMPACT-NOW) updates provide guidelines for the diagnosis of central nervous system (CNS) tumors and suggestions for future World Health Organization (WHO) classification. Following publication of the fifth edition WHO Classification of CNS Tumors (WHO CNS5) in 2021, the cIMPACT-NOW working group "Clarification" reviewed WHO CNS5 and prioritized two topics for further elucidation: (a) distinction of Glioblastoma, IDH-wildtype from Diffuse pediatric-type high-grade glioma, H3-wildtype, and IDH-wildtype and (b) clarification of subgroups of posterior fossa (PF) ependymal tumors. Recommendations regarding the IDH- and H3-wildtype diffuse high-grade gliomas include: (1) use caution assigning CNS WHO grade 4 (diagnosis of Glioblastoma, IDH-wildtype) to a "TERT promoter only", histologically low-grade, IDH-wildtype tumor; (2) EGFR gene amplification and +7/-10 chromosome copy number alterations should not be used as solitary defining features for diagnosing high-grade gliomas as Glioblastoma, IDH-wildtype in patients <40 years of age; (3) Diffuse pediatric-type high-grade glioma, H3-wildtype, and IDH-wildtype should be considered in the differential diagnosis in adults, especially those <40 years of age; (4) PDGFRA alteration, EGFR alteration, or MYCN amplification count as key molecular features of Diffuse pediatric-type high-grade glioma, H3-wildtype, and IDH-wildtype only in patients <25 years. Guidelines for improved diagnosis of posterior fossa ependymal tumors include: (1) immunohistochemical demonstration of nuclear EZHIP supports classification as PF group A ependymoma; (2) a PF ependymoma with retained nuclear H3 K27me3 expression and no nuclear EZHIP overexpression for which DNA methylation profiling is not performed should be considered as PF ependymoma, "not otherwise specified"; (3) for emerging tumors not included in WHO CNS5, "not elsewhere classified" (NEC) can be added to the diagnosis. Of note, these recommendations are not formal changes to the WHO definitions and diagnostic criteria but are intended to provide diagnostic guidance in advance of WHO CNS6.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.021 | 0.043 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.003 |
| Bibliometrics | 0.008 | 0.007 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.004 | 0.004 |
| Open science | 0.007 | 0.005 |
| Research integrity | 0.008 | 0.010 |
| Insufficient payload (model declined to judge) | 0.009 | 0.012 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".