Identification of a candidate biomarker from perfusion MRI to anticipate glioblastoma progression after chemoradiation.

Objective: To identify relevant relative cerebral blood volume biomarkers from T2* dynamic-susceptibility contrast magnetic resonance imaging to anticipate glioblastoma progression after chemoradiation.

Methods: Twenty-five patients from a prospective study with glioblastoma, primarily treated by chemoradiation, were included. According to the last follow-up MRI confirmed status, patients were divided into: relapse group (n = 13) and control group (n = 12). The time of last MR acquisition was t; MR acquisitions performed at t, t and t (respectively 2, 4 and 6 months before t) were analyzed to extract relevant variations among eleven perfusion biomarkers (B). These variations were assessed through R(B), as the absolute value of the ratio between ∆B from t to t and ∆B from t to t. The optimal cut-off for R(B) was determined using receiver-operating-characteristic curve analysis.

Results: The fraction of hypoperfused tumor volume (F_hP) was a relevant biomarker. A ratio R(F_hP) ≥ 0.61 would have been able to anticipate relapse at the next follow-up with a sensitivity/specificity/accuracy of 92.3 %/63.6 %/79.2 %. High R(F_hPg) (≥0.61) was associated with more relapse at t compared to low R(F_hPg) (75 % vs 12.5 %, p = 0.008).

Conclusion: Iterative analysis of F_hP from consecutive examinations could provide surrogate markers to predict progression at the next follow-up.

Key Points: • Related rCBV biomarkers from DSC were assessed to anticipate GBM progression. • Biomarkers were assessed through their patterns of variation during the follow-up. • The fraction of hypoperfused tumour volume (F_hP ) seemed to be a relevant biomarker. • An innovative ratio R(F_hP ) could be an early surrogate marker of relapse. • A significant time gain could be achieved in the management of GBM patients.