Intratumoral susceptibility signals in adult-type diffuse gliomas: associations with molecular profile, tumor grade, and overall survival

PurposeIntratumoral Susceptibility Signals (ITSS) are low-signal-intensity structures observed on susceptibility-weighted imaging (SWI) which may reflect intratumoral microhemorrhages, calcifications, and neovascularization. Previous studies have demonstrated associations between ITSS, glioma grade, and molecular characteristics; however, their potential role in outcome prediction remains incompletely defined. This study investigated the diagnostic and and potential prognostic role of ITSS in adult diffuse gliomas.MethodsWe retrospectively analyzed 128 adult patients with histologically confirmed diffuse gliomas who underwent preoperative MRI including SWI. ITSS were graded from 0 to 3 according to the number of susceptibility signals. Associations between ITSS grade and CNS WHO tumor grade, IDH mutation status, MGMT promoter methylation and Ki-67 labeling index (LI) were evaluated. Overall survival (OS) was assessed using Kaplan–Meier analysis and Cox proportional hazards models.ResultsITSS grade was significantly associated with WHO glioma grade (p < 0.001), with lower-grade tumors predominantly exhibiting ITSS grades 0–1 and higher-grade gliomas showing grades 2–3. IDH-mutant gliomas displayed significantly lower ITSS grades than IDH-wildtype tumors (p < 0.001). ITSS grade was positively correlated with Ki-67 labeling index (Spearman's ρ = 0.423, p < 0.001). In the survival cohort (n = 87) higher ITSS burden was significantly associated with shorter OS (ITSS 2–3 vs. 0–1: HR = 3.19, 95% CI 1.65–6.19; p < 0.001). However, this association was no longer significant after adjustment for established prognostic factors (HR = 1.40, 95% CI 0.69–2.86; p = 0.350), with IDH status emerging as the strongest independent association with shorter OS.ConclusionITSS grading on SWI is associated with CNS WHO grade, molecular profile, proliferative activity, and OS in adult-type diffuse gliomas. Although ITSS was not an independent predictor of survival after adjustment for established prognostic factors, it may serve as a readily available, non-invasive imaging correlate of tumor aggressiveness, providing complementary information for preoperative tumor characterization while definitive molecular data are pending.