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Updated: Jun 19, 2026
Fluorescence Molecular Tomography for In Vivo Imaging of Glioblastoma Xenografts
Published on: April 26, 2018
Detecting epidermal growth factor receptor tumor activity in vivo during cetuximab therapy of murine gliomas
Summer L Gibbs-Strauss1, Kimberley S Samkoe, Julia A O'Hara
1Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. sgibbs@bidmc.harvard.edu
Rationale And Objectives:
Noninvasive molecular imaging of glioma tumor receptor activity was assessed with diagnostic in vivo fluorescence monitoring during targeted therapy. The study goals were to assess the range of use for treatment monitoring and stratification of tumor types using epidermal growth factor (EGF) receptor (EGFR) status with administration of fluorescently labeled EGF and determine its utility for tumor detection compared to magnetic resonance imaging (MRI).
Materials And Methods:
EGFR+ and EGFR- glioma tumor lines (human glioma [U251-GFP] and rat gliosarcoma [9L-GFP], respectively) were used to assess these goals, having a 20-fold difference between their EGF uptakes.
Results:
Treatment with cetuximab in the EGFR+ tumor-bearing animals led to decreased EGF tumor uptake, whereas for the EGFR- tumors, no change in fluorescence signal followed treatment. This diagnostic difference in EGFR expression could be used to stratify the tumor-bearing animals into groups of potential responders and nonresponders, and receiver-operating characteristic curve analysis revealed an area under the curve (AUC) of 0.92 in separating these tumors. The nonlocalized growth pattern of U251-GFP tumors resulted in detection difficulty on standard MRI, but high EGFR expression made them detectable by fluorescence imaging (AUC = 1.0). The EGFR+ U251-GFP tumor-bearing animals could be noninvasively stratified into treated and untreated groups on the basis of fluorescence intensity difference (P = .035, AUC = 0.90).
Conclusions:
EGFR expression was tracked in vivo with fluorescence and determined to be of use for the stratification of EGFR+ and EGFR- tumors, the detection of EGFR+ tumors, and monitoring of molecular therapy.
Insights
Fluorescently labeled epidermal growth factor (EGF) receptor (EGFR) imaging noninvasively tracks EGFR status in glioma tumors. This method aids in tumor detection, stratification, and monitoring targeted therapy effectiveness.
Area of Science:
- Oncology
- Molecular Imaging
- Biotechnology
Background:
- Gliomas are primary brain tumors with varying receptor expression.
- Targeted therapies aim to inhibit specific molecular pathways, such as the epidermal growth factor receptor (EGFR).
- Noninvasive monitoring of treatment response and tumor characteristics is crucial for effective glioma management.
Purpose of the Study:
- To assess in vivo fluorescence monitoring for tracking glioma tumor receptor activity during targeted therapy.
- To evaluate the utility of fluorescently labeled EGF for stratifying tumor types based on EGFR status.
- To compare the diagnostic performance of fluorescence imaging with MRI for tumor detection.
Main Methods:
- Utilized EGFR+ (human glioma U251-GFP) and EGFR- (rat gliosarcoma 9L-GFP) tumor models.
- Administered fluorescently labeled EGF to assess uptake differences between tumor types.
- Monitored fluorescence signal changes in response to cetuximab treatment.
Main Results:
- Fluorescence imaging detected significant differences in EGF uptake between EGFR+ and EGFR- tumors.
- Cetuximab treatment reduced EGF uptake in EGFR+ tumors, while EGFR- tumors showed no change.
- Fluorescence imaging demonstrated high accuracy (AUC = 1.0) in detecting EGFR+ tumors, outperforming MRI for certain growth patterns.
- Noninvasive stratification of EGFR+ tumors into treated and untreated groups was achieved with high accuracy (AUC = 0.90).
Conclusions:
- In vivo fluorescence imaging effectively tracks EGFR expression in gliomas.
- This technique enables stratification of tumors based on EGFR status.
- Fluorescence imaging is valuable for detecting EGFR+ gliomas and monitoring molecular therapy response.
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