RT Journal Article
SR Electronic
T1 Treatment Monitoring of Immunotherapy and Targeted Therapy using <sup>18</sup>F-FET PET in Patients with Melanoma and Lung Cancer Brain Metastases: Initial Experiences
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP jnumed.120.248278
DO 10.2967/jnumed.120.248278
A1 Norbert Galldiks
A1 Diana SY Abdulla
A1 Matthias Scheffler
A1 Fabian Wolpert
A1 Jan-Michael Werner
A1 Martin W Huellner
A1 Gabriele Stoffels
A1 Viola Schweinsberg
A1 Max Schlaak
A1 Nicole Kreuzberg
A1 Jennifer Landsberg
A1 Philipp Lohmann
A1 Garry Ceccon
A1 Christian Baues
A1 Maike Trommer
A1 Eren Celik
A1 Maximilian I Ruge
A1 Martin Kocher
A1 Simone Marnitz
A1 Gereon R Fink
A1 Joerg-Christian Tonn
A1 Michael Weller
A1 Karl-Josef Langen
A1 Jürgen Wolf
A1 Cornelia Mauch
YR 2020
UL http://jnm.snmjournals.org/content/early/2020/09/04/jnumed.120.248278.abstract
AB Purpose: We investigated the value of O-(2-[18F]fluoroethyl)-L-tyrosine (18F-FET) PET for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastases (BM) since contrast-enhanced MRI often remains inconclusive. Methods: We retrospectively identified 40 patients with 107 BM secondary to melanoma (n = 29 with 75 BM) or non-small cell lung cancer (n = 11 with 32 BM) treated with ICI or TT who had 18F-FET PET (n = 60 scans) for treatment monitoring from 2015-2019. The majority of patients (n = 37; 92.5%) had radiotherapy during the course of disease. In 27 patients, 18F-FET PET was used for the differentiation of treatment-related changes from BM relapse following ICI or TT. In 13 patients, 18F-FET PET was performed for response assessement to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 months). In all lesions, static and dynamic 18F-FET PET parameters were obtained (i.e., mean tumor-to-brain ratios (TBR), time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathological findings as reference. Results: A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% (P = 0.003). Metabolic responders to ICI or TT on 18F-FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; P = 0.004). Furthermore, at follow-up, time-to-peak values in metabolic responders increased significantly (P = 0.019). Conclusion: 18F-FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.