What is the typical delay after the administration of 18F-FMISO before imaging?

For imaging with 18F-FMISO (Fluoromisonidazole), which is a radiotracer used in PET imaging to assess tumor hypoxia, a typical delay of approximately 2 hours after administration is recommended. This delay allows sufficient time for the tracer to distribute within the tissues and for it to clear from non-target areas. The radiotracer accumulates in hypoxic regions (areas with low oxygen levels), making it critical to wait for an optimal time to achieve accurate localization and quantification of these regions.

While shorter times like 30 minutes or 45 minutes may not provide the necessary clearance and distribution needed for effective imaging, a 2-hour wait optimizes the contrast between normal and hypoxic tissues, enhancing the diagnostic quality of the images. Therefore, a 2-hour delay is standard practice in many clinical settings for this type of imaging.