BACKGROUND: Both (18)F-fluorodihydroxyphenylalanine ((18)F-DOPA) and (18)F-fluoroethyltyrosine ((18)F-FET) have already been used successfully for imaging of brain tumors. The aim of this study was to evaluate differences between these 2 promising tracers to determine the consequences for imaging protocols and the interpretation of findings. METHODS: Forty minutes of dynamic PET imaging were performed on 2 consecutive days with both (18)F-DOPA and (18)F-FET in patients with recurrent low-grade astrocytoma (n = 8) or high-grade glioblastoma (n = 8). Time-activity-curves (TACs), standardized uptake values (SUVs) and compartment modeling of both tracers were analyzed, respectively. RESULTS: The TAC of DOPA-PET peaked at 8 minutes p.i. with SUV 5.23 in high-grade gliomas and 10 minutes p.i. with SUV 4.92 in low-grade gliomas. FET-PET peaked at 9 minutes p.i. with SUV 3.17 in high-grade gliomas and 40 minutes p.i. with SUV 3.24 in low-grade gliomas. Neglecting the specific uptake of DOPA into the striatum, the tumor-to-brain and tumor-to-blood ratios were higher for DOPA-PET. Kinetic modeling demonstrated a high flow constant k1 (mL/ccm/min), representing cellular internalization through AS-transporters, for DOPA in both high-grade (k1 = 0.59) and low-grade (k1 = 0.55) tumors, while lower absolute values and a relevant dependency from tumor-grading (high-grade k1 = 0.43; low-grade k1 = 0.33) were observed with FET. CONCLUSIONS: DOPA-PET demonstrates superior contrast ratios for lesions outside the striatum, but SUVs do not correlate with grading. FET-PET can provide additional information on tumor grading and benefits from lower striatal uptake but presents lower contrast ratios and requires prolonged imaging if histology is not available in advance due to a more variable time-to-peak.
BACKGROUND: Both (18)F-fluorodihydroxyphenylalanine ((18)F-DOPA) and (18)F-fluoroethyltyrosine ((18)F-FET) have already been used successfully for imaging of brain tumors. The aim of this study was to evaluate differences between these 2 promising tracers to determine the consequences for imaging protocols and the interpretation of findings. METHODS: Forty minutes of dynamic PET imaging were performed on 2 consecutive days with both (18)F-DOPA and (18)F-FET in patients with recurrent low-grade astrocytoma (n = 8) or high-grade glioblastoma (n = 8). Time-activity-curves (TACs), standardized uptake values (SUVs) and compartment modeling of both tracers were analyzed, respectively. RESULTS: The TAC of DOPA-PET peaked at 8 minutes p.i. with SUV 5.23 in high-grade gliomas and 10 minutes p.i. with SUV 4.92 in low-grade gliomas. FET-PET peaked at 9 minutes p.i. with SUV 3.17 in high-grade gliomas and 40 minutes p.i. with SUV 3.24 in low-grade gliomas. Neglecting the specific uptake of DOPA into the striatum, the tumor-to-brain and tumor-to-blood ratios were higher for DOPA-PET. Kinetic modeling demonstrated a high flow constant k1 (mL/ccm/min), representing cellular internalization through AS-transporters, for DOPA in both high-grade (k1 = 0.59) and low-grade (k1 = 0.55) tumors, while lower absolute values and a relevant dependency from tumor-grading (high-grade k1 = 0.43; low-grade k1 = 0.33) were observed with FET. CONCLUSIONS:DOPA-PET demonstrates superior contrast ratios for lesions outside the striatum, but SUVs do not correlate with grading. FET-PET can provide additional information on tumor grading and benefits from lower striatal uptake but presents lower contrast ratios and requires prolonged imaging if histology is not available in advance due to a more variable time-to-peak.
Authors: Barbara J Fueger; Johannes Czernin; Timothy Cloughesy; Daniel H Silverman; Cheri L Geist; Martin A Walter; Christiaan Schiepers; Phioanh Nghiemphu; Albert Lai; Michael E Phelps; Wei Chen Journal: J Nucl Med Date: 2010-09-16 Impact factor: 10.057
Authors: Gabriele Pöpperl; Friedrich W Kreth; Jan H Mehrkens; Jochen Herms; Klaus Seelos; Walter Koch; Franz J Gildehaus; Hans A Kretzschmar; Jörg C Tonn; Klaus Tatsch Journal: Eur J Nucl Med Mol Imaging Date: 2007-09-01 Impact factor: 9.236
Authors: Friederike C Rau; Wolfgang A Weber; Hans-Jürgen Wester; Michael Herz; Ingrid Becker; Achim Krüger; Markus Schwaiger; Reingard Senekowitsch-Schmidtke Journal: Eur J Nucl Med Mol Imaging Date: 2002-05-28 Impact factor: 9.236
Authors: Stephanie E Combs; Meinhard Kieser; Stefan Rieken; Daniel Habermehl; Oliver Jäkel; Thomas Haberer; Anna Nikoghosyan; Renate Haselmann; Andreas Unterberg; Wolfgang Wick; Jürgen Debus Journal: BMC Cancer Date: 2010-09-06 Impact factor: 4.430
Authors: Ryan S Youland; Gaspar J Kitange; Timothy E Peterson; Deanna H Pafundi; Judi A Ramiscal; Jenny L Pokorny; Caterina Giannini; Nadia N Laack; Ian F Parney; Val J Lowe; Debra H Brinkmann; Jann N Sarkaria Journal: J Neurooncol Date: 2012-10-20 Impact factor: 4.130
Authors: Stephanie E Combs; Iris Burkholder; Lutz Edler; Stefan Rieken; Daniel Habermehl; Oliver Jäkel; Thomas Haberer; Renate Haselmann; Andreas Unterberg; Wolfgang Wick; Jürgen Debus Journal: BMC Cancer Date: 2010-10-06 Impact factor: 4.430
Authors: Manuel Röhrich; Kristin Huang; Daniel Schrimpf; Nathalie L Albert; Thomas Hielscher; Andreas von Deimling; Ulrich Schüller; Antonia Dimitrakopoulou-Strauss; Uwe Haberkorn Journal: Eur J Nucl Med Mol Imaging Date: 2018-05-07 Impact factor: 9.236
Authors: Nathalie L Albert; Michael Weller; Bogdana Suchorska; Norbert Galldiks; Riccardo Soffietti; Michelle M Kim; Christian la Fougère; Whitney Pope; Ian Law; Javier Arbizu; Marc C Chamberlain; Michael Vogelbaum; Ben M Ellingson; Joerg C Tonn Journal: Neuro Oncol Date: 2016-04-21 Impact factor: 12.300
Authors: Francesco Cicone; Christian P Filss; Giuseppe Minniti; Camilla Rossi-Espagnet; Annalisa Papa; Claudia Scaringi; Norbert Galldiks; Alessandro Bozzao; N Jon Shah; Francesco Scopinaro; Karl-Josef Langen Journal: Eur J Nucl Med Mol Imaging Date: 2015-03-07 Impact factor: 9.236