Comparison of (18)F-FET and (18)F-FLT small animal PET for the assessment of anti-VEGF treatment response in an orthotopic model of glioblastoma
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
BACKGROUND: The radiolabeled amino acid O-(2-(18)F-fluoroethyl)-L-tyrosine (FET) and thymidine analogue 3'-deoxy-3'-(18)F-fluorothymidine (FLT) are widely used for positron emission tomography (PET) brain tumor imaging; however, comparative studies are scarce. The aim of this study therefore was to compare FLT and FET PET for the assessment of anti-VEGF response in glioblastoma xenografts.
METHODS: Xenografts with confirmed intracranial glioblastoma were treated with anti-VEGF therapy (B20-4.1) or saline as control. Weekly bioluminescence imaging (BLI), FLT and FET PET/CT were used to follow treatment response. Tracer uptake of FLT and FET was quantified using maximum standardized uptake (SUVmax) values and tumor-to-background ratios (TBRs). Survival, the Ki67 proliferation index and micro-vessel density (MVD) were evaluated.
RESULTS: In contrast to FLT TBRs, FET TBRs were significantly lower as early as one week after treatment initiation in the anti-VEGF group as compared to the control group. Following two weeks of treatment, both FLT and FET TBRs were significantly lower in the anti-VEGF group. In contrast, no significant difference between the treatment groups was detected using BLI. Furthermore, we found a significantly lower MVD in the anti-VEGF group as compared to the control group. However, we found no difference in the Ki67 proliferation index or mean survival time.
CONCLUSION: FET appears to be a more sensitive tracer than FLT to measure early response to anti-VEGF therapy with PET. Advances in knowledge and implications for patient care FET PET appears to be an early predictor of anti-VEGF efficacy. Confirmation of these results in clinical studies is needed.
Originalsprog | Engelsk |
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Tidsskrift | Nuclear Medicine and Biology |
Vol/bind | 43 |
Udgave nummer | 3 |
Sider (fra-til) | 198-205 |
Antal sider | 8 |
ISSN | 0969-8051 |
DOI | |
Status | Udgivet - mar. 2016 |
ID: 164971922