%0 Journal Article %A Galldiks, Norbert %A Dunkl, Veronika %A Ceccon, Garry %A Tscherpel, Caroline %A Stoffels, Gabriele %A Law, Ian %A Henriksen, Otto M. %A Muhic, Aida %A Poulsen, Hans S. %A Steger, Jan %A Bauer, Elena K. %A Lohmann, Philipp %A Schmidt, Matthias %A Shah, Nadim J. %A Fink, Gereon R. %A Langen, Karl-Josef %T Early treatment response evaluation using FET PET compared to MRI in glioblastoma patients at first progression treated with bevacizumab plus lomustine %J European journal of nuclear medicine and molecular imaging %V 45 %N 13 %@ 0340-6997 %C Heidelberg [u.a.] %I Springer-Verl. %M FZJ-2018-04047 %P 2377–2386 %D 2018 %X BackgroundThe goal of this prospective study was to compare the value of both conventional MRI and O-(2-18F-fluoroethyl)-L-tyrosine (FET) PET for response evaluation in glioblastoma patients treated with bevacizumab plus lomustine (BEV/LOM) at first progression.MethodsAfter chemoradiation with concomitant and adjuvant temozolomide, 21 IDH wild-type glioblastoma patients at first progression (age range, 33–75 years; MGMT promoter unmethylated, 81%) were treated with BEV/LOM. Contrast-enhanced MRI and FET-PET scans were performed at baseline and after 8–10 weeks. We obtained FET metabolic tumor volumes (MTV) and tumor/brain ratios. Threshold values of FET-PET parameters for treatment response were established by ROC analyses using the post-progression overall survival (OS) ≤/>9 months as the reference. MRI response assessment was based on RANO criteria. The predictive ability of FET-PET thresholds and MRI changes on early response assessment was evaluated subsequently concerning OS using uni- and multivariate survival estimates.ResultsEarly treatment response as assessed by RANO criteria was not predictive for an OS>9 months (P = 0.203), whereas relative reductions of all FET-PET parameters significantly predicted an OS>9 months (P < 0.05). The absolute MTV at follow-up enabled the most significant OS prediction (sensitivity, 85%; specificity, 88%; P = 0.001). Patients with an absolute MTV below 5 ml at follow-up survived significantly longer (12 vs. 6 months, P < 0.001), whereas early responders defined by RANO criteria lived only insignificantly longer (9 vs. 6 months; P = 0.072). The absolute MTV at follow-up remained significant in the multivariate survival analysis (P = 0.006).ConclusionsFET-PET appears to be useful for identifying responders to BEV/LOM early after treatment initiation. %F PUB:(DE-HGF)16 %9 Journal Article %$ pmid:29982845 %U <Go to ISI:>//WOS:000450713500016 %R 10.1007/s00259-018-4082-4 %U https://juser.fz-juelich.de/record/849952