Added prognostic value of DCE blood volume imaging in patients with suspected recurrent or residual glioblastoma-A hybrid [F]FET PET/MRI study.

BACKGROUND

Magnetic resonance imaging (MRI) cerebral blood volume (CBV) measurements improve the diagnosis of recurrent gliomas. The study investigated the prognostic value of dynamic contrast-enhanced (DCE) CBV imaging in treated IDH wildtype glioblastoma when added to MRI or amino acid positron emission tomography (PET).

METHODS

Hybrid [F]FET PET/MRI with 2CXM (2-compartment exchange model) DCE from 86 adult patients with suspected recurrent or residual glioblastoma were retrospectively analyzed. High CBV tumor volume (VOL), and contrast-enhancing (VOL) and [F]FET active tumor (VOL) volumes were delineated. Absolute and fractional high CBV subvolumes within VOL and VOL were determined. Associations with overall survival (OS) were assessed by Cox analysis.

RESULTS

Adjusted for methyltransferase gene status and steroid use all total tumor volumes were individually associated with shorter OS. Adding VOL to VOL or VOL only the effect of VOL was prognostic of OS (hazard ratio [HR] 1.327,  = .042 and 1.352,  = .011, respectively). High CBV subvolumes within both VOL and VOL were associated with shorter survival (HR 1.448,  = .042 and 1.416,  = .011, respectively), and the low CBV subvolumes with longer survival (HR 0.504,  = .002 and .365,  = .001, respectively). The fraction of VOL and VOL with high CBV was a strong predictor of OS with shorter median OS in upper versus lower tertiles (8.3 vs 14.5 months and 7.1 vs 15.6 months, respectively, both  < .001).

CONCLUSIONS

The high CBV tumor volume was a strong prognosticator of survival and allowed for the separation of high- and low-risk subvolumes underlining the heterogeneous physiological environment represented in the contrast-enhancing or metabolically active tumor volumes of treated glioblastoma.