Nuklearmedizin 2021; 60(02): 155-156
DOI: 10.1055/s-0041-1726765
WIS-Vortrag
Onkologie – Bildgebung

Diagnosis of pseudoprogression following lomustine-temozolomide chemoradiation in newly diagnosed glioblastoma patients using FET PET

JM Werner
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
,
J Weller
2   Department of Neurology, University Hospital Bonn, Division of Clinical Neurooncology, Bonn
,
G Ceccon
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
,
C Schaub
2   Department of Neurology, University Hospital Bonn, Division of Clinical Neurooncology, Bonn
,
C Tscherpel
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
,
P Lohmann
3   Research Center Juelich, Inst. of Neuroscience and Medicine (INM-4), Juelich
,
EK Bauer
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
,
N Schäfer
2   Department of Neurology, University Hospital Bonn, Division of Clinical Neurooncology, Bonn
,
G Stoffels
3   Research Center Juelich, Inst. of Neuroscience and Medicine (INM-4), Juelich
,
C Baues
4   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Radiation Oncology and Cyberknife Center, Cologne
,
E Celik
4   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Radiation Oncology and Cyberknife Center, Cologne
,
S Marnitz
4   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Radiation Oncology and Cyberknife Center, Cologne
,
C Kabbasch
5   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neuroradiology, Cologne
,
GH Gielen
6   University Hospital Bonn, Department of Neuropathology, Bonn
,
GR Fink
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
,
KJ Langen
3   Research Center Juelich, Inst. of Neuroscience and Medicine (INM-4), Juelich
,
U Herrlinger
2   Department of Neurology, University Hospital Bonn, Division of Clinical Neurooncology, Bonn
,
N Galldiks
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Department of Neurology, Cologne
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Ziel/Aim The CeTeG/NOA-09 phase-III trial demonstrated a significant survival benefit of lomustine-temozolomide chemoradiation in newly diagnosed glioblastoma patients with methylated O6-methylguanine-DNA methyltransferase promoter. Following lomustine-temozolomide chemoradiation, late and prolonged pseudoprogression may occur. We here evaluated the value of amino acid PET using O-(2-[18F]fluoroethyl)-L-tyrosine (FET) for differentiating pseudoprogression from tumor progression.

Methodik/Methods We retrospectively identified patients (i) who were treated off-study according to the CeTeG/NOA-09 trial, (ii) had progressive MRI findings after radiotherapy, and (iii) underwent additional FET PET imaging for diagnostic evaluation (number of scans, 1-3). Maximum and mean tumor-to-brain ratios (TBRmax, TBRmean) and dynamic FET uptake parameters (e.g., time-to-peak) were calculated. In patients with more than one FET PET scan, relative changes of TBR values were evaluated, i.e., an increase or decrease of >10 % compared to the reference scan was considered as tumor progression or pseudoprogression. Diagnostic performances were evaluated using receiver operating characteristic curve analyses and Fisher’s exact test. Diagnoses were confirmed histologically or clinicoradiologically.

Ergebnisse/Results We identified 24 patients with 34 FET PET scans. Within 5-25 weeks after radiotherapy (median time, 9 weeks), pseudoprogression occurred in 10 patients (42 %). The accuracy of TBRmean, TBRmax, and time-to-peak calculated from the FET PET performed 10 ± 7 days after the progressive MRI to identify pseudoprogression was 83 %, 75 %, and 75 %, respectively (thresholds, TBRmean < 1.95, TBRmax < 3.05, time-to-peak >35 minutes; all P < 0.05). The integration of relative changes of TBRmean further improved the accuracy (88 %; P < 0.001).

Schlussfolgerungen/Conclusions Lomustine-temozolomide chemoradiation may increase the pseudoprogression rate considerably. FET PET parameters appear of value for the diagnosis of pseudoprogression.



Publication History

Article published online:
08 April 2021

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