Purpose: The purpose of this study was to investigate the changes of tumor hypoxia as a result of neoadjuvant chemotherapy (NAC) by measuring the changes of [(18)F]fluoromisonidazole ([(18)F]FMISO) positron emission tomography (PET) uptake, as well as to look into the ability of [(18)F]FMISO PET to predict the NAC result.
Procedures: A total of 13 patients with locally advanced head and neck squamous cell carcinoma underwent [(18)F]FMISO PET scans before and after NAC. For analysis of PET index, maximum standardized uptake value, tumor-to-muscle ratio, and hypoxic volume (HV) were measured.
Results: All PET indexes of [(18)F]FMISO significantly decreased after NAC. Although HV in primary tumor and a few indexes before NAC in responder was lower than that in nonresponder, none of the indexes were statistically significant.
Conclusions: Pretreatment [(18)F]FMISO could not predict NAC outcome in this study. However, [(18)F]FMISO uptake significantly decreased after NAC, and [(18)F]FMISO PET seemed to be a useful noninvasive tool for detecting hypoxia reduction after NAC.