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Objective To evaluate the clinical role of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) for the diagnosis and staging of prostate cancer.Methods 18F-FDG PET/CT and 99Tcm-MDP ECT whole body bone scan were both performed in 40 patients with prostate cancer proved by biopsy or surgery.We then evaluated the diagnostic value of 18F-FDG PET/CT for prostate cancer.Results Of 40 cases,17 cases were detected by 18 F-FDG PET/CT with a sensitivity of 42.5％.Of the 17 cases with lymphoma metastasis,8 cases were detected by CT while 15 cases were detected by 18F-FDG PET/CT.The sensitivity of 18F-FDG PET/CT is 88.2％.Though 18F-FDG PET/CT and 99Tcm-MDP bone scan have a similar sensitivity in detecting bone metastases,18 F-FDG PET/CT has better specificity and accuracy in detecting bone metastases than that of an 99Tcm-MDP bone scan.Conclusions Though the diagnostic value of 18F-FDG PET/CT in detecting primary focus of prostate is limited,it still has an important role in detecting lymph node metastases and bone metastases.18F-FDG PET/CT has its superiority in prostate cancer staging.It can also help clinicians to select the regimen of treatment.
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Objective To evaluate the application of early 18F-FDG PET-CT imaging after radiofrequency ablation (RFA) of hepatic malignancies. Methods Fifteen patients with liver tumors (five hepatocellular carcinoma, ten colorectal cancer liver metastasis ) underwent RFA as part of clinical management. The lesions were all hypermetabolic on PET-CT performed within 2 weeks prior to RFA. All subjects underwent 18F-FDG PET-CT (early PET-CT) within 24 hours after RFA. Total photopenia, focal uptake, and rim-shaped uptake were regarded as complete ablation, residual tumor, and inflammation, respectively. Follow-up PET-CT scans were performed as the reference standard. Results Twelve patients showed total photopenia at the ablation site on the early PET-CT scan, and in all of these patients, total photopenia at the ablation sites was seen on the follow-up PET-CT scans. Two patients had focal uptake at the ablation sites on the early PET-CT scan, and both of these foci increased in size and intensity, which were compatible with residual tumors at the time of ablation. Only one patient had rim-shaped uptake on the early PET-CT scan. The rim-shaped uptake disappeared on PET-CT performed 3 months later, which indicated the nature of inflammation. Conclusions There is infrequent inflammatory uptake at the RFA site of liver tumors on 18F-FDG PET-CT if scanning is performed within 24 hours after ablation. Thus, early PET-CT has the potential to evaluate the efficacy of an RFA procedure by indicating tumor-free as total photopenia and residual tumors as focal uptake.
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Objective:Position emission tomography/computed tomography(PET/CT) is a new bio-imaging system which is combined metabolic with anatomic imaging.This study was to compare the accuracy of conventional staging methods(including computed tomography,ultrasound,magnetic resonance imaging,and detection of bone marrow) with that of PET/CT for lymphoma staging and re-staging. Methods:A total of 42 patients with lymphoma diagnosed by operation or biopsy,received conventional and PET/CT staging.The accuracy of these two methods and their impact on lymphoma staging were compared.Results:The accuracy of PET/CT scan was 95.2%(40/42),and that of conventional staging was 78.6%(33/42).The detection rates of internal lymph node were 97.1%(66/68) and 88.2%(60/68),respectively.The detection rates of outer lymph node were 91.7%(22/24) and 58.3%(14/24),respectively.Compared with conventional staging methods,7 cases were up-staged and 2 cases were down-staged by PET/CT,which led to the change of therapy in 8 cases.Conclusion:PET/CT scan is more sensitive and accurate than conventional staging methods in staging and restaging of lymphoma.