A Comparative Study of Noninvasive Hypoxia Imaging with (18)F-Fluoroerythronitroimidazole and (18)F-Fluoromisonidazole PET/CT in Patients with Lung Cancer

PURPOSE: This is a clinical study to compare noninvasive hypoxia imaging using (18)F-fluoroerythronitroimidazole ((18)F-FETNIM) and (18)F-fluoromisonidazole ((18)F-FMISO) positron emission tomography/computed tomography (PET/CT) in patients with inoperable stages III–IV lung cancer. METHODS: A total of forty-two patients with inoperable stages III–IV lung cancer underwent (18)F-FETNIM PET/CT (n = 18) and (18)F-FMISO PET/CT (n = 24) before chemo/radiation therapy. The standard uptake values (SUVs) of malignant and normal tissues depict (18)F-FETNIM PET/CT and (18)F-FMISO PET/CT uptake. Tumor-to-blood ratios (T/B) were used to quantify hypoxia. RESULTS: All patients with lung cancer underwent (18)F-FETNIM PET/CT and (18)F-FMISO PET/CT successfully. Compared to (18)F-FMISO, (18)F-FETNIM showed similar uptake in muscle, thyroid, spleen, pancreas, heart, lung and different uptake in blood, liver, and kidney. Significantly higher SUV and T/B ratio with (18)F-FMISO (2.56±0.77, 1.98±0.54), as compared to (18)F-FETNIM (2.12±0.56, 1.42±0.33) were seen in tumor, P = 0.022, <0.001. For the patients with different histopathological subtypes, no significant difference of SUV (or T/B ratio) was observed both in (18)F-FMISO and (18)F-FETNIM in tumor. A significantly different SUV (or T/B ratio) was detected between < = 2cm, 2~5cm, and >5cm groups in (18)F-FMISO PET/CT, P = 0.015 (or P = 0.029), whereas no difference was detected in (18)F-FMISO PET/CT, P = 0.446 (or P = 0.707). Both (18)F-FETNIM and (18)F-FMISO showed significantly higher SUVs (or T/B ratios) in stage IV than stage III, P = 0.021, 0.013 (or P = 0.032, 0.02). CONCLUSION: (18)F-FMISO showed significantly higher uptake than (18)F-FETNIM in tumor/non-tumor ratio and might be a better hypoxia tracer in lung cancer.