Artikel
Dynamic 18FET-PET predicts the outcome in anaplastic glioma WHO° III and is correlated with IDH 1 mutation status
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Veröffentlicht: | 2. Juni 2015 |
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Objective: The outcome in patients with anaplastic glioma (WHO° III) without IDH1/2 mutation is comparable to the unfavorable course of glioblastoma. Dynamic 18FET-PET has been shown to have prognostic influence in high-grade glioma independent of other clinical parameters. In the present study, we have correlated dynamic parameters acquired from 18FET-PET imaging with the occurrence of IDH1/2 mutation as well as vascularization and clinical progression.
Method: We selected 96 patients with a glioma WHO° III who received a 18FET-PET at primary diagnosis. In all cases IDH1/2 mutation, MGMT promoter methylation status, LOH 1p/19q status and the degree of vascularity as detected by quantification of CD34-positive tumor area were determined. The maximum "tumor-to-brain"-quotient (TBRmax) and the minimum "time-to-peak" (TTPmin) were analyzed as 18FET-PET parameters. Clinical outcome measures were progression free survival (PFS) and overall survival (OS).
Results: From a total of 96 patients, 52/96 (54%) showed no IDH1 mutation. The IDH 1 status did not correlate with TBRmax (2.9 vs. 3.2 without vs. with IDH 1 mutation; p=0.24), but with TTPmin (p<0.001): 37/41 (90%) patients with a TTPmin <12.5 min showed no IDH 1/2 mutation, while a TTPmin >12.5 min was often associated with IDH1 mutation (31/43 patients (72%), 4 patients could not be evaluated). The TTPmin was independent of the degree of vascularization; in addition, there was no correlation between TTPmin and MGMT methylation status or LOH 1p/19q. In an interim analysis of 53 cases, patients without IDH 1 mutation or with a TTPmin <12,5 min had a significantly shorter PFS (10.0 vs. 37.4 months vs. 37.4 months and 9.8; p<0.001) and OS (20.5 and 22.0 months versus median not reached, respectively; p<0.001). In the multivariate analysis, both TTPmin and IDH 1 status were independent predictors of OS.
Conclusions: In anaplastic gliomas, early TTPmin <12.5 min is associated with a lack of IDH 1 mutation, but not with the extent of vascularization, the MGMT status or LOH 1p/19q. TTPmin and IDH1 mutation are both associated with clinical outcome.