Hypoxia18F-FAZA PET/CT imaging in lung cancer and high-grade glioma: open issues in clinical application

Purpose: Hypoxia can influence response to chemo and radiotherapy in different tumours, including non-small cell lung cancer (NSCLC) and high-grade gliomas (HGG). PET/CT can non-invasively investigate hypoxia and18F-FAZA seems to be the most promising radiotracer. However, there are still controversial issues related to image analysis and data interpretation hampering the effective possibility to translate the use of this imaging modality in clinical applications. The aim of the present pictorial review is to provide insights and answers on the open issues related to the potential clinical applicability of18F-FAZA PET/CT for hypoxia delineation. Methods: From Pubmed and Scopus databases, a literature research has been performed with the following research filters for both NSCLC and HGG: (1) time frame: last 10 years; (2) language: English; (3) species: human. Applied searching keywords were “hypoxia” or “hypoxic” and “PET” and “lung cancer” for NSCLS and “hypoxia”, “PET” and “glioma” for HGG. Papers not strictly matching the imposed search filters have not been considered. Results: The literature search led to 76 papers for NSCLC, but for the purpose of the review only 10 have been considered, after double-checking and exclusion if not matching the imposed search filters. For HGG, the selected filters lead to 19 papers but only 8 have been considered for data analysis. Results on the use of18F-FAZA PET/CT in two different settings are reported in the present pictorial essay and methodological suggestions for clinical practice are presented through the description of addressed representative case reports. Conclusions: Based on literature evidence and presentation of relevant clinical case reports, issues related to18F-FAZA PET/CT in clinical settings have been addressed, providing possible solutions that may help the reliable use of this imaging method in clinical practice.