Nuklearmedizin 2020; 59(02): 126-127
DOI: 10.1055/s-0040-1708239
Wissenschaftliche Vorträge
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© Georg Thieme Verlag KG Stuttgart · New York

Imaging findings following regorafenib in malignant gliomas: FET PET adds valuable information to anatomical MRI

JM Werner
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Dept. of Neurology, Cologne
,
C Tscherpel
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Dept. of Neurology, Cologne
,
G Stoffels
2   Research Center Juelich, Inst. of Neuroscience and Medicine (INM-4), Juelich
,
GR Fink
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Dept. of Neurology, Cologne
,
KJ Langen
2   Research Center Juelich, Inst. of Neuroscience and Medicine (INM-4), Juelich
,
N Galldiks
1   Faculty of Medicine and University Hospital Cologne, University of Cologne, Dept. of Neurology, Cologne
› Author Affiliations
Further Information

Publication History

Publication Date:
08 April 2020 (online)

 

Ziel/Aim Recent phase 2 data show promising effectivity of the antiangiogenic multikinase inhibitor regorafenib for glioblastoma treatment at first progression (1). Following antiangiogenic treatment, amino acid PET provides valuable additional diagnostic information regarding treatment-related changes on MRI (e.g., non-enhancing tumor progression). In contrast, only a little is known about regorafenib. The present prospective pilot study aimed to determine the value of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET for the assessment of regorafenib-related treatment effects.

Methodik/Methods Fourteen patients (age range, 38-81 years) with progressive malignant glioma (median number of relapses, 2; range, 1-4) were enrolled. Seven of 14 patients were eligible for data evaluation and underwent regorafenib therapy (120-160 mg per day, 21 days on, 7 days off; median number of cycles, 2). FET PET and MRI was performed at baseline and after the second cycle. MRI response was evaluated according to RANO criteria (2). FET uptake 20-40 minutes p.i. was quantified by maximum and mean tumor-to-brain ratios (TBRmax, mean).

Ergebnisse/Results In 4 of 7 patients, FET PET provided clinically relevant additional information. In two patients with MRI improvement despite subsequent clinical progression, increasing FET uptake (range of relative TBRmax increase, 34-94 %) was consistent with pseudoresponse. In one patient, a FET uptake below a TBRmax < 1.6 despite progressive disease on MRI suggested pseudoprogression. In another patient, increasing FET uptake (relative TBRmax increase, 138 %) enabled an earlier diagnosis of tumor progression (time benefit, 5 weeks), in which MRI was unchanged.

Schlussfolgerungen/Conclusions Following regorafenib and in contrast to conventional MRI, FET PET was able to identify pseudoresponse and pseudoprogression, and to detect tumor progression earlier.

 

  • Literatur/References:

  • 1 Lombardi. et al., 2019 Lancet Oncol.
  • 2 Wen. et al., 2010 J Clin Oncol.