Abstract Date: 4/7/2014
Jan Coburger, M.D.
Jens Engelke, MD
Angelika Scheuerle, MD
Dietmar Thal, MD, PhD
Michal Hlavac, MD (Günzburg, Germany)
Thomas Kretschmer, MD, PhD (Oldenburg, Germany)
Christian Wirtz, MD, PhD
Ralph König, MD, PhD (Günzburg, Germany)
Glioblastoma multiforme(GBM) shows an invasive growth pattern extending into neural tissue beyond margins of contrast enhancement in MRI.
Aim of the present study is to evaluate whether 5 aminolevulinic-acid fluorescence(5-ALA) provides an additional benefit to detect invasive tumor compared to intraoperative MRI(iMRI).
We prospectively enrolled 34 patients harboring a GBM with intended gross total resection. All patients had surgery using iMRI and 5-ALA guided resection following a specific protocol: First a white-light tumor resection was performed. Then, spatial location of residual fluorescence was subsequently marked. After that, an iMRI was performed and residual uptake of contrast was marked. Navigated biopsies were taken from these areas and from additional sites according to surgeons judgment. Cross tables and ROC-curves were calculated assessing performance of the imaging methods for tumor detection alone and for combined detection including infiltration zone(pathological tissue). Correlations of histopathological findings with imaging results were tested using Spearman´s rho.
114 histopathological samples were harvested.Sensitivity for tumor detection was significantly higher (p<0.001) in 5-ALA(0.85) than in iMRI (0.41). Specificity was significantly (p<0.001) lower in 5-ALA(0.43) as in iMRI(0.70). For detection of pathological tissue 5-ALA exceeded iMRI in specificity (0.80 vs. 0.60) and sensitivity (0.91 vs. 0.66) significantly(p<0.001). Imaging results of iMRI and 5-ALA did not correlate significantly. Only 5-ALA showed a significant correlation with final histopathological diagnosis of specimen and with typical histopathological features of GMS.
Imaging results of 5-ALA and iMRI are significantly different at the border zone of GBMs. 5-ALA has a higher sensitivity and a lower specificity for tumor detection than Gd-DTPA-enhanced iMRI. For detection of infiltrating tumor 5-ALA is superior to Gd-DTPA-enhanced iMRI concerning both sensitivity and specificity. Thus, additional use of 5-ALA to iMRI might be beneficial to maximize extend of resection.
Article ID: AA-28636