ABSTRACT Background Timely identification of early recurrence (≤ 6 months) may improve prognosis of glioblastoma (GBM), but conventional MRI has shown limited accuracy in this setting. Purpose Risk‐assessment models and a nomogram were constructed by integrating SyMRI metrics, clinical–pathological variables, and cMRI features, including contrast‐enhanced T1‐weighted imaging and fluid‐attenuated inversion recovery (FLAIR) findings. Study Type Retrospective observational study. Population Seventy‐eight patients with GBM (median age, 59 years; 44 56.4% males). Field Strength/Sequence 3 T; pre‐ and post‐contrast three‐dimensional T1‐weighted imaging, FLAIR, and SyMRI. Assessment Histogram‐based quantitative metrics were extracted from SyMRI maps using subregions defined on fused FLAIR and contrast‐enhanced T1‐weighted images. All candidate clinical–pathological variables, cMRI features, and SyMRI‐derived metrics were entered directly into least absolute shrinkage and selection operator (LASSO) regression for variable selection. Risk‐assessment models and a nomogram were constructed. Statistical Tests Multivariable logistic regression, multicollinearity assessment using variance inflation factors, receiver operating characteristic curve analysis with DeLong test, stratified 10‐fold cross‐validation, leave‐one‐out cross‐validation, nested 5‐fold cross‐validation, calibration curves, and decision curve analysis. A two‐sided p < 0.05 was considered statistically significant. Results Multivariate analysis identified reduced T2 entropy (< 2.113) in enhancement‐corresponding regions (odds ratio OR = 0.08), thick linear or nodular residual cavity wall enhancement (OR = 5.28), corpus callosum involvement (OR = 5.08), and O6‐methylguanine‐DNA methyltransferase (MGMT) promoter methylation (OR = 0.19) as variables associated with early recurrence. The integrated model achieved the highest performance (AUC = 0.864). Nested cross‐validation showed moderate internal validation performance, with an AUC of 0.724 (0.722–0.726). Data Conclusion Histogram‐based pre‐radiotherapy SyMRI metrics, particularly T2 entropy, were associated with early GBM recurrence. The integrated model achieved the highest apparent performance; nested internal validation showed moderate performance. External validation in larger multicenter cohorts is required before clinical implementation. Evidence Level 3. Technical Efficacy Stage 2.
Quan et al. (Tue,) studied this question.