Aquaporin positron emission tomography differentiates between grade III and IV human astrocytoma

Abstract

BACKGROUND: Aquaporin (AQP) water channels play a signifcant role in mesenchymalmicrovascular proliferation and infltrative growth. AQPs are highly expressed in malignantastrocytomas, and a positive correlation is observed between their expression levels andhistological tumor grade.OBJECTIVE: To examine the utility of aquaporin positron emission tomography (PET) fordifferentiating between astrocytoma grade III and grade IV using the AQP radioligand[11C]TGN-020.METHODS: Fifteen astrocytoma patients, grade III (n = 7) and grade IV (n = 8), and 10healthy volunteers underwent [11C]TGN-020 aquaporin PET imaging. Surgical tissues ofastrocytoma patients were examined for histopathological grading using the WHO classifcation standard and expression of AQP1 and AQP4 immunohistochemically.RESULTS: Mean standardized uptake values of astrocytoma grade III and IV (0.51 ± 0.11 vs1.50 ± 0.44, respectively) were higher than normal white matter (0.17 ± 0.02, P