Comparison of combined PET/CT and 18F-FDG PET only in cervical cancers
Аннотация
Aim: To assess anatomical localization of 18F-FDG uptake in primary cervical cancers with PET alone as compared to combined PET/CT. Method: A retrospective analysis of 18F-FDG studies in 15 patients (median=41, range=24–54 years) with cervical cancer was undertaken. Two-dimensional whole-body images were acquired using a GE discovery LS PET/CT scanner and data reconstructed using OSEM and CT based attenuation correction. SUVs were calculated for all FDG avid lesions. Three observers independently interpreted PET only images, and after a week, interpreted combined PET/CT images. 18F-FDG avidity at both the primary and non-primary sites was designated an anatomical territory and the degree of confidence for localization noted (0=exact region unknown, 1=probable, 2=definite). Change in confidence was calculated using the above scoring system and expressed as a percentage. Results: Of the 15 patients, FDG PET only identified 14 primary lesions (SUVmax=8.14) and 20 non-primary sites (SUVmax=6.9). Combined PET/CT identified all 15 primary lesions and 20 non-primary sites. Anatomical localization with FDG PET only was correct in 4/9 primary and 8/20 non-primary sites. Combined PET/CT correctly identified anatomical sites in all FDG avid lesions. Conclusion: 18F-FDG PET/CT, in comparison with 18F-FDG PET only, improves confidence of localizing of 18F-FDG avid sites by 59% in primary and 78% in non-primary sites.