The use of MR perfusion parameters in differentiation between glioblastoma recurrence and radiation necrosis

Introduction:
This study focuses on the challenge of distinguishing between tumour recurrence and radiation necrosis in glioma treatment using magnetic resonance imaging (MRI). Currently, accurate differentiation is possible only through surgical biopsy, which is invasive and may cause additional damage. The study explores non-invasive methods using dynamic susceptibility contrast (DSC) MR perfusion with parameters like relative peak height (rPH) and relative percentage of signal-intensity recovery (rPSR).

Material and methods:
Among retrospectively evaluated patients (multicentre study) with an initial diagnosis of the primary and secondary brain tumour, 47 met the inclusion criteria and were divided into two groups, the recurrent glioblastoma (GBM) WHO IV group and the radiation necrosis group, based on MRI of the brain. All patients enrolled into the recurrent GBM group had a second surgical intervention.

Results:
Mean, minimum and maximum rPH values were significantly higher in the recurrent GBM group than in the radiation necrosis group (p < 0.001), while rPSR values were lower in the recurrent GBM group than in the radiation necrosis group (p = 0.011 and p = 0.012).

Discussion:
This study investigates the use of MR perfusion curve characteristics to differentiate between radiation necrosis and glioblastoma recurrence in post-treatment brain tumours. MR perfusion shows promising potential for distinguishing between the two conditions, but it also has certain limitations. Despite challenges in finding a sufficient cohort size, the study demonstrates significant differences in MR perfusion parameters between radiation necrosis and GBM recurrence.

Conclusions:
The results demonstrate the potential usefulness of these DSC perfusion parameters in discriminating between glioblastoma recurrence and radiation necrosis.