The effect of additional delayed images for detection of peritoneal implants with (18)F-fluorodeoxyglucose (FDG) PET/CT

Objectives To analyze the potential effect of (18)F-fluorodeoxyglucose (FDG) PET/CT using additional delayed images for the detection of peritoneal implants in recurrent suspected ovarian cancer patients.

Methods The present study retrospectively included 27 patients (mean age: 54.1±10.6 years) with clinical or radiological suspicion of recurrent disease. Patients without peritoneal implants did not included to the study. Patients were evaluated in 3 groups according to their peritoneal implant size as; 0.5-1 cm (Group 1), 1-2 cm (Group2) and > 2 cm (Group 3). A whole body PET/CT scan was performed at 60 min (standard images) and after 2 hr (delayed images) post-injection of 14.1±3.8 mCi of (18)F-FDG. Visual and quantitative SUV analyses of PET/CT findings were performed.

Results 16 patients in Group 1 were detected to have same lesions in early and delayed images; whereas 24 and 25 patients were detected peritoneal implants in group 2 with early and delayed images, respectively. In Group 2, 69 and 71 lesions were detected in early and late images, respectively. Meanwhile, 15 and 17 patients were detected to have peritoneal implants in Group 3 in early and delayed images, respectively. In this group, 46 and 58 lesions were detected in early and delayed images, respectively. All lesions were demonstrated to have increased FDG uptake in delayed images. The SUV max values of the lesions seen in early images were increased from 9.3±4.7 to 11.4±5.6 (p< 0.05) in delayed images.

Conclusions The present study revealed that more peritoneal implants may be detected especially in patients with peritoneal implants < 1 cm with delayed images