- Design
- Retrospective cohort with quantitative MRI phenotyping
- Population
- 82 patients with glioblastoma after chemoradiation
- Primary outcome
- Overall survival by necrosis phenotype
- Effect
- HR 0.35 (p = 0.001); adjusted HR 0.29 (p = 0.001)
A retrospective study of 82 patients with glioblastoma imaged after chemoradiation characterised necrosis on MRI using two shape measures, volume density and surface-to-volume ratio, to define low-risk and high-risk necrosis phenotypes.
The low-risk phenotype was compact rather than dispersed, with smoother margins and less fragmentation. Patients with it had a markedly lower hazard of death (HR 0.35, p = 0.001), which held after adjustment for tumour volume, MGMT status, age and performance score (HR 0.29). Low-risk necrosis also showed lower perfusion and higher oxygen extraction on advanced imaging.
This is a single-cohort, hypothesis-generating study and the method needs external validation. But necrosis is already visible on routine post-treatment MRI, and noting whether it is compact or fragmented costs nothing and may add to prognostic discussion.
- Compact necrosis with smooth margins after chemoradiation was associated with longer survival in glioblastoma.
- The association was independent of MGMT status, age, tumour volume and performance status.
- Fragmented, dispersed necrosis marked the higher-risk group.
- This is a research measure; it should not be used alone for prognosis in clinical reports.
Why it matters
Routine MRI may already hold prognostic information that current reporting ignores.
Don't overread it
This retrospective study of 82 patients has not been validated in an independent cohort.
The statistics, in plain English
A hazard ratio of 0.29 means patients with the low-risk pattern died at about a third of the rate of the others at any given time, after accounting for the main known prognostic factors.
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