The feasibility of [(18)F]EF5-PET/CT to image hypoxia in ovarian tumors: a clinical study

RATIONALE: Evaluation of the feasibility of [(18)F]EF5-PET/CT scan in identifying hypoxic lesions in ovarian tumors in prospective clinical setting. METHODS: Fifteen patients with a suspected malignant ovarian tumor were scanned with [(18)F]EF5 and [(18)F]FDG-PET/CT preoperatively. The distribution of [(18)F]EF5-uptake, total intraabdominal metabolic tumor volume (TMTV), and hypoxic subvolume (HSV) were assessed. RESULTS: [(18)F]EF5-PET/CT suggested hypoxia in 47% (7/15) patients. The median HSV was 87 cm(3) (31% of TMTV). The [(18)F]EF5-uptake was detected in primary tumors and in four patients also in intra-abdominal metastases. The [(18)F]EF5-uptake in cancer tissue was low compared to physiological excretory pathways, complicating the interpretation of PET/CT images. CONCLUSIONS: [(18)F]EF5-PET/CT is not feasible in ovarian cancer imaging in clinical setting due to physiological intra-abdominal [(18)F]EF5-accumulation. However, it may be useful when used complementarily to FDG-PET/CT.