Clinical study of F-18 FDG PET and GA-67 imaging in patients lymphoma

Purposes: Clinical value was studied in the patients with lymphomas by comparing the F-18 FDG PET and Ga-67 whole body imaging. Methods: 23 cases with lymphomas proved by the histopathology were included in this study, the F-18 FDG PET and Ga-67 whole body imaging were performed in Pre- and Post-therapy. PET scan was performed after 40-50 mins of injected intravenously F-18 FDG 3-5mCi (0.06mCi/kg) .The ADAC CPET-250.was used. The fasting of the patients is at least 4 hours before imaging. Ga-67 whole body imaging was performed after 48-72 hours of injected intravenously 370 MBq (10mCi) Ga-67 .Both of images were analyzed visually. That means the positive findings showed the abnormally high uptake of radioactivity. Results. F-18 FDG PET scan demonstrated the 53 positive lesions in 23 patients.However, the Ga-67 whole body imaging showed 44 (83%) positive lesions in 19 (82.6%) patients. Of these lesions,there are 36% in head-neck,21.5% in abdomen,35% in mediastinal,7.5% in pelvic.The findings comparing PET and Ga-67whole body scan showed the concordance in 19 cases with 44 lesions.In 53 lesions detected by PET scan,Ga-67 imaging did not detect 9 lesions, 1 localized in the head-neck, 4 in abdomen,2 in the pelvic and 2 in the mediastinal, the lesion size rang is 0.6-3.2 cm. Conclusion: F-18 FDG PET scan is obviously better than Ga-67 whole body imaging in the staging of the patients with lymphomas.The diagnostic accuracy of Ga-67 imaging will be affected by the lesion size and localization. (authors)