VTE Risk Peaks in First Six Months After High-Grade Glioma Surgery

Researchers analyzed 894 patients with newly diagnosed glioblastoma or grade 3–4 IDH-mutant gliomas treated between 2010 and 2023. They estimated VTE incidence over time, assessed factors associated with early and late events, and compared observed rates with predictions from the GliomaPredictVTE tool.

For IDH-wild-type glioblastoma, estimated VTE incidence was 21.5% at six months and 26.4% at 12 months. For IDH-mutant gliomas, the corresponding estimates were 6.3% and 8.3%. Incidence rose most rapidly during the first six months after surgery, with a change-point around that time. Early VTE was associated with older age, limb weakness, dependence on ambulation, and radiotherapy alone; later VTE, occurring from six months to five years, was associated with older age and smoking.

The prediction tool underestimated VTE incidence: mean predicted risks at six and 12 months were 11.0% and 17.4%, compared with observed cumulative incidences of 19.9% and 23.0%. The findings identify a period of heightened risk and support prospective evaluation of primary prophylaxis in high-risk patients. They do not establish that prophylaxis should be changed in practice.