[18F]fluoroethyltyrosine-positron emission tomography-based therapy monitoring after stereotactic iodine-125 brachytherapy in patients with recurrent high-grade glioma.

Abstract

Therapy monitoring of glioma after stereotactic iodine-125 brachytherapy (SBT) remains challenging because posttherapeutic changes in magnetic resonance imaging can mimic tumor progression. We evaluated the prognostic value of serial [18F]fluoroethyltyrosine (FET)-positron emission tomographic (PET) scans for therapy monitoring of high-grade glioma (HGG) after SBT. Thirty-three patients with recurrent HGG were included. Serial FET-PET scans were performed prior to therapeutic intervention and at 3-month intervals during the first year after SBT. FET-PET evaluation was performed by both conventional data analysis and kinetic analysis. Prognostic factors were obtained from proportional hazard models. Median local progression-free survival (LPFS) was 11.1 months. Maximal standardized background uptake value (SUVmax/BG) and biologic tumor volume (BTV) differentiated accurately between therapeutic effects and local tumor progression at the 6-month and subsequent examinations. Increasing uptake kinetics at baseline (p < .05) and during follow-up (p < .01) were stringently associated with a longer LPFS. Early increase in FET uptake after SBT is not unequivocally associated with tumor progression; it might be induced by reactive changes and could easily lead to a misclassification of the tumor status (pseudoprogression). Six months after SBT (or later), however, increased SUVmax/BG and BTV values are associated with a worse prognosis. Multivariate analysis stresses the prognostic importance of dynamic studies.

• Authors: Nathalie L Jansen, Bogdana Suchorska, Silke B Schwarz, Sabina Eigenbrod, Juergen Lutz, Vera Graute, Peter Bartenstein, Claus Belka, Friedrich W Kreth, Christian la Fougère
• Journal: Molecular imaging (Mol Imaging) Vol. 12 Issue 3 Pg. 137-47 (May 2013) ISSN: 1536-0121 [Electronic] England
• PMID: 23490440 (Publication Type: Journal Article)

Chemical References

• O-(2-fluoroethyl)tyrosine
• Tyrosine
• Iodine

Topics

• Brachytherapy (methods)
• Disease-Free Survival
• Glioma (diagnosis, pathology, therapy)
• Humans
• Iodine (therapeutic use)
• Magnetic Resonance Imaging
• Positron-Emission Tomography (methods)
• Tyrosine (analogs & derivatives)