Differentiation of recurrent glioblastoma multiforme from radiation necrosis after external beam radiation therapy with dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging.
OBJECTIVE
To investigate whether cerebral blood volume (CBV), peak height (PH), and percentage of signal intensity recovery (PSR) measurements derived from the results of T2-weighted dynamic susceptibility-weighted contrast material-enhanced (DSC) magnetic resonance (MR) imaging performed after external beam radiation therapy (EBRT) can be used to distinguish recurrent glioblastoma multiforme (GBM) from radiation necrosis.


METHODS
Fifty-seven patients were enrolled in this HIPAA-compliant institutional review board-approved retrospective study after they received a diagnosis of GBM, underwent EBRT, and were examined with DSC MR imaging, which revealed progressive contrast enhancement within the radiation field. A definitive diagnosis was established at subsequent surgical resection or clinicoradiologic follow-up. Regions of interest were retrospectively drawn around the entire contrast-enhanced region. This created T2-weighted signal intensity-time curves that produced three cerebral hemodynamic MR imaging measurements: CBV, PH, and PSR. Welch t tests were used to compare measurements between groups.


RESULTS
Mean, maximum, and minimum relative PH and relative CBV were significantly higher (P < .01) in patients with recurrent GBM than in patients with radiation necrosis. Mean, maximum, and minimum relative PSR values were significantly lower (P < .05) in patients with recurrent GBM than in patients with radiation necrosis.


CONCLUSIONS
These findings suggest that DSC perfusion MR imaging may be used to differentiate recurrent GBM from EBRT-induced radiation necrosis.
Department of Radiology, Neuroradiology Section, University of California, San Francisco, CA 94143, USA.
Ramon F
RF
Barajas
Jamie S
JS
Chang
Mark R
MR
Segal
Andrew T
AT
Parsa
Michael W
MW
McDermott
Mitchel S
MS
Berger
Soonmee
S
Cha
D001810:Blood Volume; D001921:Brain / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis* / Q000532:radiotherapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D011832:Radiation Injuries / Q000175:diagnosis*; D011879:Radiotherapy Dosage; D012680:Sensitivity and Specificity
D003287:Contrast Media