^99mTc-CXCR4-L for Imaging of the Chemokine-4 Receptor Associated with Brain Tumor Invasiveness: Biokinetics, Radiation Dosimetry, and Proof of Concept in Humans

Figure 6

Follow-up of patients with suspected glioma by using magnetic resonance imaging (MRI) of the brain (A, D, and G), correlated with the lesion-specific uptake of ^99mTc-CXCR4-L SPECT/MRI (B, E, and H), and with the immunohistochemical detection of CXCR4 expression (C, F, and I). MRI of patient 1 with low-grade glioma (A) has no contrast enhancement and low radiotracer uptake (B); MRI of patient 4 with high-grade glioma (D) shows a hyperintense lesion in the frontal lobe and high radiotracer uptake (E); MRI of patient 9 (G) shows hyperintense areas in the subcortical location within the insulas and a rounded lesion in the right cerebral hemisphere negative for ^99mTc-CXCR4-L uptake (H), which suggests a diagnosis of gliosis. The biopsy of patient 1 with low-grade glioma (C) shows diffuse cytoplasmic CXCR4 protein immunostaining (+), while the biopsy of patient 4 with high-grade glioma (F) presents intense recognition of CXCR4 in the cytoplasmic and nuclear cell compartments (+++). Gliosis tissue of patient 9 (I) showed no HRP (horseradish peroxidase) staining, indicating the absence of CXCR4 cell expression, which correlates with the negative ^99mTc-CXCR4-L uptake.