Background and purpose: F-18-fluoroazomycinarabinoside (F-18-FAZA) is a promising hypoxia radiopharmaceutical agent with outstanding biokinetic parameters. We aimed to determine the accuracy of F-18-FAZA-PET/CT scan in detecting hypoxic regions within the tumor using immunohistochemical markers in a pilot study.
Patients and methods: Eleven patients with primary or recurrent laryngeal squamous cell carcinoma were indicated for total laryngectomy (TLE). Patients underwent F-18-FAZA-PET/CT scan before TLE. Hypoxic regions inside the laryngeal tumor were determined. After TLE, regions with high uptake on F-18-FAZA-PET scan were selected for immunohistochemical examination for exogenous (pimonidazole) and endogenous (HIFI alpha, CA-IX and GLUT-1) hypoxia markers. To assess the accuracy of F-18-FAZA-PET scanning, radiopharmacon accumulation was related with immunohistochemical expression of hypoxia markers.
Results: Inter- and intratumoral heterogeneity of tumor hypoxia was observed on F-18-FAZA-PET scan. Nine of the eleven tumors were hypoxic with F-18-FAZA-PET. Hypoxia could also be detected with pimonidazole, HIFI alpha, CA-IX and GLUT-1 expression in some tumors. No clear association was observed between F-18-FAZA uptake and hypoxia markers.
Conclusions: This pilot study could not prove the accuracy of F-18-FAZA-PET in determining hypoxic sub-volumes in laryngeal cancer. Further study is required to investigate the benefit of F-18-FAZA-PET imaging in radiotherapy planning. (C) 2015 Elsevier Ireland Ltd. All rights reserved.