TY - JOUR AU - Galldiks, Norbert AU - Abdulla, Diana SY AU - Scheffler, Matthias AU - Wolpert, Fabian AU - Werner, Jan-Michael AU - Huellner, Martin W AU - Stoffels, Gabriele AU - Schweinsberg, Viola AU - Schlaak, Max AU - Kreuzberg, Nicole AU - Landsberg, Jennifer AU - Lohmann, Philipp AU - Ceccon, Garry AU - Baues, Christian AU - Trommer, Maike AU - Celik, Eren AU - Ruge, Maximilian I AU - Kocher, Martin AU - Marnitz, Simone AU - Fink, Gereon R AU - Tonn, Joerg-Christian AU - Weller, Michael AU - Langen, Karl-Josef AU - Wolf, Jürgen AU - Mauch, Cornelia TI - Treatment Monitoring of Immunotherapy and Targeted Therapy using 18 F-FET PET in Patients with Melanoma and Lung Cancer Brain Metastases: Initial Experiences JO - Journal of nuclear medicine VL - 62 IS - 4 SN - 2159-662X CY - New York, NY PB - Soc. M1 - FZJ-2021-00862 SP - 464-470 PY - 2021 AB - 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 metastasis (BM) since contrast-enhanced MRI often remains inconclusive. Methods: We retrospectively identified 40 patients with 107 BMs secondary to melanoma (n = 29 with 75 BMs) or non–small cell lung cancer (n = 11 with 32 BMs) treated with ICI or TT who had 18F-FET PET (n = 60 scans) for treatment monitoring from 2015 to 2019. Most patients (n = 37; 92.5%) had radiotherapy during the course of the disease. In 27 patients, 18F-FET PET was used to differentiate treatment-related changes from BM relapse after ICI or TT. In 13 patients, 18F-FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 mo). 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 neuropathologic findings as a 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 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. LB - PUB:(DE-HGF)16 C6 - 32887757 UR - <Go to ISI:>//WOS:000658416500008 DO - DOI:10.2967/jnumed.120.248278 UR - https://juser.fz-juelich.de/record/890281 ER -